bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of optical dilatation before retrograde intrarenal surgery on success and complications: results of the RIRSearch group study.
Authors: Sancak Eyup Burak , Basatac Cem , Akgul Murat , Cinar Onder , Ozman Oktay , Yazıcı Cenk Murat , Akpinar Haluk
Published: April 2021

Aims: The guidelines propose optical dilatation before retrograde
intrarenal surgery (RIRS), but there are no evidence-based studies
concerning the impact of optical dilatation with semirigid ureteroscopy
(sURS) in the literature. The aim of this study was to evaluate the
effect of optical dilatation through sURS prior to the procedure on the
success and complications of RIRS. Methods: In a multicentre
retrospective study, 422 patients were included in the study. The
patients were divided into two groups according to whether sURS was to
be performed. Patients’ demographics, stone parameters and operative
outcomes were compared. Surgical success was defined as no or up to 3-mm
residual stone fragments without the need for additional procedures. The
independent predictors for surgical success were determined with a
multivariable logistic regression model. Results: Of the 422 patients,
133 (31.5%) were in the sURS group and 289 (68.5%) were in the
non-sURS group. Operation time in the sURS group was significantly long
(p<0.0001). A ureteral access sheath (UAS) could not be placed
in four (3.0%) patients in the sURS group, nor in 25 (8.7%) patients
in the non-sURS group (p=0.03). Compared with the non-sURS group, the
intraoperative complication rate was low in the sURS group (14 (4.8%)
vs 1 (0.8%), p=0.04). The surgical success rate was higher in the sURS
group (p=0.002). Nevertheless, sURS had no independent effect on
surgical success. We have found two independent predictors for surgical
success rate: stone number (p<0.0001, OR:2.28) and failed UAS
placement (p=0.035, OR:3.49) Conclusion: Optical dilatation with sURS
before RIRS increases surgical success by raising the rate of UAS
placement and reducing the rate of intraoperative complications. We
suggest that this method can be routinely applied in the group of
patients who have not been passively dilated with a JJ stent
Correlation of Complete Blood Count Parameters and Ferritin Levels at the Time of Diagnosis with the Prognosis of Patients Hospitalized Due to Covid 19
Authors: Çiftçiler Rafiye , Ciftciler Ali Erdinc , batman adnan
Published: April 2021

Background and Aim:The novel coronavirus (SARS-CoV-2) that causes novel
coronavirus pneumonia (COVID-19) is the third fatal coronavirus. The
prognosis of disease varies depending on patient’s specialties. The aim
of this study was to evaluate the correlation of CBC parameters and
ferritin levels at the time of diagnosis with the prognosis of patients
hospitalized due to COVID 19. Materials and Methods: In this
retrospective study, 1320 patients hospitalized at the Aksaray
University Training and Research Hospital between July 2020 and December
2020 were evaluated. Results: All of the patients were hospitalized
because of symptoms associated with COVID 19. There were 688 males and
632 females with a median age of 70 (19-98) at the time of
hospitalization with COVID 19 symptoms. The median follow-up time was 7
(range, 1-57) days in hospital for all patients. Median age was
significantly higher in patients who do not respond to treatment and
have mortality (p<0.001). Most of the patients with mortality
were males (p=0.001). There was a statistically significant difference
in the parameters other than monocyte and basophil among the hemogram
parameters checked at the time of presentation. Neutrophil / lymphocyte
ratio was significantly higher in patients with mortality
(p<0.001). Conclusion: In conclusion, this study indicates
that by using the most simple and routine hematological tests at the
time of COVID-19 diagnosis, it may be possible to predict a patient’s
prognosis. This will help patients receive early clinical care, reducing
patient mortality and aiding in the control and prevention of the
outbreak.
COMPARISON OF PATIENTS WITH ACUTE ISCHEMIC STROKE WITH AND WITHOUT COVID-19
Authors: OKUYAN Dilek YILMAZ , GÖLEN Meltem KARACAN
Published: April 2021

Objectives: Information on the incidence of acute ischemic stroke (AIS),
which is an important cause of morbidity and mortality, its association
with COVID-19, and its course in infected patients in this pandemic
period is limited. In this study, it was aimed to compare the
demographic, clinical and stroke characteristics, and the laboratory,
prognosis and mortality findings of patients with AIS with and without
COVID-19. Methods: This study included 43 patients with a positive
nasopharyngeal PCR test who were followed up for AIS, and 70 patients
without COVID-19 who were followed up for AIS during the same period.
Results: Poor prognosis and mortality were found to be significantly
higher in the AIS group with COVID-19 compared with the non-COVID-19 AIS
group. In the AIS group with COVID-19, a higher rate of intensive care
unit (ICU) need (40% vs. 5%), higher intubation rate (35% vs. 3%)
and longer hospital stay (12.9 ± 10.8 vs. 6.6 ± 4.0 days) were observed.
In the laboratory examinations, C-reactive protein, ferritin, D-dimer,
troponin, and lactate dehydrogenase levels were found to be
significantly higher in patients with AIS who were positive for
COVID-19. An increase in D-dimer, ferritin and thrombocytopenia were
found to be associated with mortality in the COVID-19 positive AIS
group. Conclusion: Patients with AIS and COVID-19 had a higher rate of
ICU need, higher intubation rate, longer hospital stay, higher
mortality, and poorer prognosis than those without COVID-19. High levels
of ferritin, D-dimer and fibrin degradation products were associated
with a poor prognosis. Keywords: COVID-19, stroke, prognosis, mortality
Does chronotherapy for essential hypertension matter by class? A systematic review and meta-analysis
Authors: Kuang Hongyu , Chen Yunlin
Published: April 2021

Objectives The study was performed to evaluate the efficacy and safety
of chronotherapy of hypertension with different medications monotherapy
or a combination compared with traditional regimens Methods Three
databases including PubMed, EMBASE and the Cochrane Library were
searched, from the inception of each database to 10 April 2020. The
Review Manager 5.4 was adopted for meta-analyses and subgroup analyses.
The blood pressure delta (Δ) was used as mean of differences (MD) with
95% confidence intervals (CIs), and the estimated effect for events
estimates the 95% CIs for frequency of events. The adults with
essential hypertension were treated with chronotherapy and traditional
regimens. Results Twenty-eight RCTs, recruiting 1865 patients in
bedtime/evening dosing and 1867 in awakening/morning dosing, were
enrolled in this quantitative review. Meta-analysis showed no
significant differences for overall drug-related AEs (RR=0.81, P=0.17;
I2=41%), but an obvious reduction of risk for overall withdrawals
(RR=0.52, P=0.005; I2=0.0%) with bedtime dosing. No statistically
significant differences were noted for clinic BP and diurnal BP, but
24-hour (48-hour) BP, nocturnal BP, morning BP, and non-dippers (%)
showed obvious reductions, statistically. By class, there existed
different efficacy between 2 administrations, with great decrease in
nocturnal BP control and changes in circadian rhythm with RAAS blockers
monotherapy, but an all-day control of BP for CCBs and diuretics. With
regard to a combination, no significant differences in BP management
were detected and the data about beta-receptor blockers were limited.
Conclusions The safety and efficacy of chronotherapy in antihypertensive
drugs might be based on the classes.
Pediatric Pulmonology Year in Review 2020: Physiology
Authors: Delecaris Angela , Averill, Samantha , Krasinkiewicz Jonathan , Saunders Jessica , Ren Clement
Published: April 2021

Pulmonary physiology is a core element of pediatric pulmonology care and
research. This article reviews some of the notable publications in
physiology that were published in Pediatric Pulmonology in 2020.
Exploring Spatio-temporal change in global land cover using categorical intensity analysis
Authors: Lamchin M , Bilintoh Thomas , Lee Woo-Kyun , Ochir Altansukh , Lim Chul-Hee
Published: April 2021

Global land degradation and urbanization are rapidly progressing during
the 21st century. Herein, we assessed Spatio-temporal changes in global
land cover using categorical intensity analyses from 1992 to 2018 to
evaluate global land degradation and urbanization. Specifically, we
evaluated the decrease, increase, and expansion processes and observed
temporal differences. These evaluations were performed on a global scale
across continents and climates at a category level for six-term
intervals. Intensity analysis is a means of characterizing differences
between sets at multiple time points using mathematics. In this study,
inputs were gridded land cover from 1992, 1997, 2002, 2007, 2012, 2015,
and 2018 and for six land categories: “Cropland,” “Forest,”
“Shrubland,” “Built,” “Bare areas,” and “Other” The analysis of
change for the 26 years shows that the cropland area increased globally
by 786,656 km2 between 1992 and 2018. The areas occupied by forests
continuously decreased by 936,960 km2, especially in South America which
experienced the highest decline. Urban areas increased by 436,084 km2,
with the highest increase observed in temperate regions. This paper
concludes that for the last 26 years, land has been converted and
degraded attributable to urbanization in temperate regions.
Additionally, in South America and tropical regions, the expansion of
cropland is the biggest contributor to the decline in “Forests” and
“Shrubland”. The largest component of change was observed for the
“Built” category. while, “Forest” and “Cropland” experienced
significant losses and gains in the first, second, and third intervals.
Plant communities and potential native phytoremediator species in petroleum hydrocarbon-polluted desert systems
Authors: Al_Ateeqi Sarah , Al-Musawi Layla , Sharma Virender , Abdullah Meshal , Ma Xingmao
Published: April 2021

This paper reported the recovery of desert plant communities after
twenty years of oil-derived hydrocarbon contamination in desert habitats
of Kuwait, caused by the First Gulf War (1990 – 1991). The hypothesis
that certain native desert plant species can tolerate weathered
oil-polluted soils with oil breakdown products (i.e., polycyclic
aromatic hydrocarbons ( PAHs)) and have the potential to function as
bioindicators and phytoremediator species for oil-polluted soil was
tested. A field survey of 200 quadrat sampling plots at seven
hydrocarbon-contaminated and unpolluted desert areas in Kuwait was
performed that recorded 42 plant species, with Haloxylon salicornicum,
Cyperus conglomeratus and Rhanterium epapposum as the most dominant
species. Analysis of plant tissues indicated plant uptake and
accumulation of some PAHs. H. salicornicum was used as a representative
species in a controlled field study that included growth of plants in
hydrocarbon-polluted and unpolluted soils in two separate desert areas
under similar growth conditions. Results showed a significant decrease
in plant biomass in oil-contaminated soil compared to those from the
uncontaminated site. However, the plants appeared green and healthy in
both sites, and showed no overt stress. The results suggest that some
desert plant communities exhibit signs of recovery after severe oil
pollution, and that H. salicornicum may serve as a phytoremediator of
oil-contaminated desert soils. Our results also demonstrated that some
desert plant communities could be cultivated in oil fields to reduce
hydrocarbon contamination and provide guide to other ecosystem services
through improving soil quality and biodiversity.
Factors influencing rehabilitation outcomes in prelingually deafened late implanted cochlear implant users and development of a nomogram
Authors: Liu Riyuan , WANG Qian , Jiao Qingshan , Ji Fei , zhao hui , Li Jianan , Yang SM
Published: April 2021

Objectives: Our study aimed to identify potential factors that influence
rehabilitation outcomes in late-implanted adolescents and adults with
prelingual deafness and attempted to develop a reliable nomogram.
Design: This retrospective study included 120 subjects less than 30
years of age who had received cochlear implantation at a single medical
center. The Categories of Auditory Performance (CAP) scale was used to
evaluate the rehabilitation outcomes. A nomogram was constructed using
the R and EmpowerStats software. Results: Univariate analysis indicated
higher rates of auditory performance improvement in younger aged
subjects. Residual hearing and regular and longer implant use were more
common among subjects showing auditory performance improvement.
Multivariate analysis identified residual hearing (Hazard Ratio, 6.11;
95% Confidence Interval, 1.83-20.41; P<0.01), age at
implantation (Hazard Ratio, 0.31; 95% Confidence Interval, 0.14-0.83;
P=0.02) and regular CI use (Hazard Ratio, 7.79; 95% Confidence
Interval, 2.50-24.20; P<0.01) as independent predictors for
auditory performance improvement. The nomogram’s predictive performance
was satisfactory as verified by the calibration curve and Receiver
operating characteristic (ROC) curve. Conclusions: We demonstrated that
residual hearing, younger age, and regular CI use were associated with
auditory performance improvement in this cochlear implant user
population. Our nomogram model demonstrated satisfactory predictive
performance for this population.
Global South: Conceptual Approaches and SocioEconomic Processes
Authors: Yakovlev P. P.
Published: April 2021

In a dynamic world, developing in the direction of polycentricism, the countries of Asia, Africa and Latin America, forming together the so-called Global South, are increasingly prominent. Today, the Global South comprises nearly two-thirds of the UN member states, accounts for about 80% of the world’s population, about 50% of world GDP and about a half of total international trade. These dry figures alone point to the paramount methodological, scientific and practical importance of studying the economic and socio-political issues of the Global South, a comprehensive analysis of its role in the world economy and politics, in the globalization, and also in geoeconomic and geopolitical relations. Equally relevant is the analysis of the Global South’s participation in the international community’s efforts to combat global challenges, including climate change, the eradication of poverty, the fight against cross-border terrorism and drug trafficking, humanity’s victory over the COVID-19 pandemic and the launch of the recovery economic growth undermined by the coronacrisis. According to the author’s of the article point of view, the former colonial and dependent countries forming the Global

South, many of which have achieved state independence in the last 50-60 years, have accumulated considerable experience of joint actions to defend their economic and political interests, established mechanisms and organizations of cooperation in a variety of fields. Far from simplifying the extremely difficult present situation and not turning a blind eye to existing problems and difficulties, it is logical to assume that a rich historical experience and a large international weight can enable the countries of the Global South to participate actively in building a more sustainable, just and secure world order.
Chinese Aid to the Industrial Development of the South: Input into Post-Industrialization of China
Authors: Kalashnikov D. B.
Published: April 2021

The article discusses the true goals and benefits of China’s assistance to the South. A hypothesis reveals the relationship between China’s transition to an innovative development model and its interest in the industrialization of the least developed countries. The tasks of modernizing the economy and the national interests of China in the context of the modern international labor division are analyzed. To ensure the growth of incomes of the population to the level of developed countries, the creation of a post-industrial structure of the economy is required. This means that a number of industrial functions must be transferred to such backward countries that, without Chinese capital and technology, are not able to industrialize. In addition, for China, the problem of equilibrium of the balance of payments is urgent, the solution to which is to increase imports of simple goods and make direct investments within the Chinese Global Value Chains. Analysis of directions and first results of Chinese development assistance confirmed its important contribution to solving these problems, as well as its systemic nature within the framework of the Belt and Road Initiative. The Initiative coordinates the construction of power plants, all types of infrastructure, and on their basis the development of industry and consumption under the control of Chinese companies. Therefore, all types of grants or concessional assistance to the South can be considered as investments into the development of the Chinese economy, which has gone beyond national borders. At the same time, participation in the Initiative brings benefits and growth prospects up to the level of the modern PRC for the most backward countries, but does not create growth opportunities for countries with already developed industry and an average standard of living, on the contrary, it reduces their space for post-industrialization.
Chinese Export to the African Countries: Links with Chinese Energy Projects
Authors: Gemueva K. A.
Published: April 2021

The article examines the relationship between China’s exports to African countries and the implementation of energy projects by Chinese companies. The structure of Chinese exports to Africa and trends in the development of bilateral trade is analyzed. Key factors explaining the close correlation between exports and project implementation are: first, the significant volume of tied financing provided by Chinese banks for the construction of energy infrastructure in African countries, second, the need of these countries to purchase a lot of high-tech equipment in the absence of relevant industries on their territory. The dynamics of supplies of specialized equipment from China used for the construction of various types of power plants - hydroelectric power plants, thermal power plants, wind power plants and solar power plants - is considered in detail. The article provides examples of energy projects of Chinese companies in African countries, for which the supply of equipment is directly found in the imports of the respective countries from China. The tendency for Chinese companies to open production facilities in African countries, in particular cement plants and a photovoltaic modules plant, is noted. The author concludes that the African market remains extremely promising for the implementation of energy projects and the sale of relevant Chinese products despite some negative factors.
Political Culture of Transforming Countries: The Experience of China in the Past 40 Years since Reform and Opening Up
Authors: Haiting F.
Published: April 2021

Since the establishment of political culture analysis framework by Almond, it has become an important tool of political science and political analysis. The basic consensus on political culture is that a good political culture can promote political development. Many countries in transformation expect to shape their own civic culture as soon as possible to match their democratization process, but things often go against their wills. They are faced with a dilemma between traditional culture and civic culture at the very beginning of transformation. Besides, the development of political culture does not always present the simple path of traditional to modern type. Therefore, it is very necessary to reflect the principles of political culture development in combination with history and reality. From the view of Chinese scholars, political culture is neither only belief, feeling and attitude of individual, nor the ideology of a nation, but has multi-level content including ideology, value, psychology and action. This view combines the method of political culture analysis, the definition of Soviet culturology and the understanding of Chinese traditional culture. In transforming countries, the development of political culture is mainly manifested in the change and interaction of political subcultures. And at the same time, political subculture interacts with the change of social structure and political system. There are six main types of political subculture in transforming countries: political subculture of countryside and peasants, workers and migrant workers, private entrepreneurs, bureaucrats and officials, middle class and network. Through the analysis of these main types of political subculture in China after the reform and opening up, it can be concluded that political culture may present a complex path of development, and there may also be a variety of different development patterns and ideal forms.
Changing Geopolitics and Negotiating Postures in the India-China Border Dispute
Authors: Daulet Singh Z.
Published: April 2021

The article is based on the author’s most recent book Powershift: India-China Relations in a Multipolar World (2020). It retraces the most salient moments and episodes in the India China border issue ever since the crisis broke out in 1959. What we learn from history is Chinese leaders have often shaped their policy on India as part of a wider geopolitical calculus, typically linked to the degree of pressure Chinese perceive on other geopolitical fronts. For India too, the nature of great powers relations impacts how it formulates China policy. This basic framework has remained relevant until the present day.

Over the past decade, as the world order began shifting to a multipolar balance of power, India and China have confronted challenges in their relationship. The relationship is at a crossroad, and both Delhi and Beijing are struggling to find an equilibrium that allows both sides to pursue their interests and visions. Nevertheless, as Asia is returning to what it was for 1,800 years of the last two millennia, and, it is that big picture trend that Indian and Chinese leaders must pay attention to. Ultimately, this means stabilising India China relations
Post-Soviet Central Asia in the Focus of Interests of Major Asian States (2019-2020)
Authors: Malysheva D. B.
Published: April 2021

The study aims at identifying some areas of international political interaction between post-Soviet Central Asian states and the major economic powers of Asia -China, India and Japan. The task is to determine their interests in the Central Asian region with an emphasis on the political component. The current state of political cooperation between China, India, Japan and the countries of Central Asia is considered. Their joint efforts to solve the problems and threats facing the sustainable development of the region are characterized, while overcoming those problems occurs within the framework of the formation of both bilateral and multilateral relations. The dynamics of political and military interaction between China and its Central Asian partners is revealed. It is shown that the regional security sphere is directly linked by China with the problem of protecting its own economic interests in the countries undergoing its Belt and Road program, aimed at changing the economic landscape not only in Central Asia, but throughout Asia. India and Japan, whose positions have come closer against the background of rising China, has defined their own strategies for Central Asia. Politics of major Asian powers in post-Soviet Central Asia are analyzed through the prism of the emergence of a polycentric world in Asia. Its distinctive features are: the emergence of new regional “centers of power”; their confrontation along the line of Sino-Pakistani, Sino-Indian rivalries; involvement of external players (the U.S.) in regional processes. In this regard, attention is drawn to the activities of such a multilateral international structure as the Shanghai Cooperation Organization (SCO), as well as to the development of alternative infrastructure projects and concepts - QUAD, Indo-Pacific, Blue Dot Network. The results of the study are formulated in the following conclusion: the countries of Central Asia and the major regional economic powers in Asia base their relations on the foundation of mutually beneficial interests and equal partnership of independent states.
Assessment of Factors and Indicators Influencing the Cyclical Development of the Economy of Azerbaijan
Authors: Ahmadova E. M.
Published: April 2021

We are proposing the results of economic development factors analysis, and there influence in forming and display of the economic cycles. The purpose of this article is to identify significant indicators of the cyclical development Azerbaijan economy for the capable of predicting and regulating phases of the onset of business cycle. Were checking 20 different indicators based by the annual data of the State Statistical Committee from 1998 to 2018. The relationship and influence of interest rates and the cyclical Azerbaijan economy development were examined. The methodological basis of this work became an analysis of such fundamental research data as papers IMF and the National Bureau of Economic Research (NBEI) of the United States. Scientific methods of our research were an indicator approach, complemented by a qualitative analysis and a correlation-regression analysis. The calculations were performed by the freely distributed modern software - the statistical environment R, the most dynamically developing program in its class. So acyclic, countercyclical, and pro-cyclic indicators were identified by us. The features of the influence of these indicators on cyclic development in modern conditions were identified, their significance was determined. It was concluded that the possibility of economic cycles forecasting by the various phases indicators contributes to the modeling of economic activity. The results of the research can be applied both to monitor the development of the Azerbaijan economy and to predict the onset of the corresponding economic phases with the aim of adapting and reducing crises’ negative impact at the micro and macro levels.
Assessment of the Competitiveness of the Diamond Cutting Industry in India (Case Study: The Gujarati Diamond Cutting Cluster)
Authors: Galistcheva N. V. , Khromova N. G.
Published: April 2021

The aim of the research is the comprehensive analysis of the Indian diamond cutting industry’s competitiveness (case study: Gujarati diamond cutting cluster). The authors show that the promotion of the diamond industry has a significant positive impact not only on the development of the economy of Gujarat, but also on the entire Indian economy as a whole. The authors pay attention to the evolution of the development of the Gujarat diamond cutting cluster, as well as its modern trends through the prism of the current situation on the world diamond market in the 2010s.

The subject of the article is Gujarat diamond cutting cluster and the research question is to evaluate its drivers and limits. The working hypothesis of the study is the following: the competitiveness of the Indian diamond cutting industry is largely determined by the significant role of the state, which is generally typical for the Indian economy as a whole.

The theoretical basis of the research is the synthesis of M.Porters concept of competitiveness of national economy branches and the mathematical approach of B.Balassa to the assessment of the revealed comparative advantages of the country on the specific product’s world market. The research is based on the systematic approach to the study of national economy using basic methods of scientific knowledge such as induction and deduction, analysis and synthesis as well as field research.

The specific feature of this article is a detailed analysis of the competitiveness model of the Indian diamond cutting industry, as well as the calculation of the Balassa index and the drawing the appropriate graphs.

The article presents different data on the place of the Indian diamond industry on the global market and India’s achievements in the special equipment production and fostering the creation of specific factors. Future studies should focus on further research on specific factors of competitiveness of Indian diamond cutting industry, as well as the role of the state in the Indian economy.
Clusters in Africa's Economy as a Perspective Model of Production
Authors: Kalinichenko L. N. , Morozenskaya E. V.
Published: April 2021

For attracting private capital to the economy, African governments allocate territories for commercial and industrial use within Special Economic Zones (SEZ). This is an important factor in export diversification (primarily of manufactured products), expanding country’s participation in global value chains, and creating new jobs. Despite different specialization from labor-intensive (textile production, agriculture, etc.) to high-tech sectors, most of the existing SEZs are ineffective due to the underdevelopment of African markets, weak competition, large-scale corruption, but to a large extent - as a result of insufficient interconnection between individual producers.

Economic space organization through the creation of clusters - production efficiency and the emergence of a special type of competition -allows them to use common infrastructure, labor and raw materials markets; jointly export products; exchange knowledge and technologies, which is significant in terms of the industrial revolution 4.0. Clusters have the characteristics of “growth poles” - territorial conglomerates that, due to their special position and infrastructural advantages, become locomotives of industrial growth, spreading to other regions.

This is especially important given the prevalence of highly inefficient micro, small and medium-sized companies in African economies, a significant part of which is in the informal sector. Clusters, emerging as a rule “from below”, can turn into structure-forming elements of the economy (both at the national and regional levels), but only on condition of organizational and financial support from individual states and their economic communities. This is in the African economies interest, as evidenced by their gradual reorientation towards the domestic market development, as well the regional market expansion within the framework of integration associations.
Colecistitis xantologranulomatosa que imita el cáncer vesicular. Reporte de caso
Authors: Garcia Belén , Fonte Alex , Iza Erika
Published: April 2021

La colecistitis xantogranulomatosa es una enfermedad poco común que se presenta clínicamente  con dolor en hipocondrio derecho, cuyos diagnósticos diferenciales más importantes son colecistitis crónica y cáncer de vesícula. En estudios de imagen se observa engrosamiento de la pared vesicular con irregularidades en su trayecto, el tratamiento es la colecistectomía laparoscópica o colecistectomía abierta, siendo el diagnóstico de confirmación histopatológico. Además, se asocia con presencia de adherencias intra-abdominales que pueden dificultar su extracción y genera complicaciones quirúrgicas. Presentamos el caso de un paciente masculino de 45 años con clínica dolor abdominal y estudio ecosonográfico de sospecha de cáncer de vesícula. Tras estudios complementarios se realiza colecistectomía encontrándose en el reporte histopatológico la presencia de  senos de Rokitanski Aschoff y granulomas constituidos por células gigantes tipo cuerpo extraño e histiocitos espumosos característicos de colecistitis xantogrenulomatosa. El paciente fue dado de alta con adecuada evolución y sin complicaciones.
Asociación entre uso de cigarrillo electrónico e historia de accidente cerebrovascular en mujeres adultas de EE. UU. en el año 2018
Authors: Kleynner Kleynner
Published: April 2021

La disminución de oxígeno en el cerebro que produce la expocisión prolongada al humo del cigarrillo y sus consecuencias ya han sido estudiadas, sin embargo, aún falta mucho por determinar si el cigarrillo electrónico produce o no los mismos efectos en el organismo.
La epidemiologia microbiológica de una unidad rural de cuidados intensivos en Ecuador
Authors: Gaus David , Larco Danny
Published: April 2021

Objetivo: Existe mucha información sobre las causas de infecciones bacterianas en Unidades de Cuidados Intensivos (UCI) en paises de altos ingresos. Por otro lado, hay una carencia de la misma información de UCIs en países de bajos y medianos ingresos (PBMI). Además, existe una escasez de estos datos de UCIs rurales en PBMI. 

Metodología: Se presenta un estudio retrospectivo y descriptivo del perfil bacteriano de una nueva UCI rural en Ecuador que cuenta con un laboratorio de microbiología durante un periodo de tres años.

Resultados: Un total de 336 aislamientos fueron recogidos durante 36 meses de aspirado traqueal 142 (42.4%), Orina 46 (13.7%), Sangre 37 (11.0%), Herida 29 (8.6%), Liquido 21 (6.3%), Otros 62 (18.4%). Organismos aislados incluyeron: Klebsiella pneumoniae 85 (25.3%) fue el aislado mas común, seguido de E coli 66 (19.6%), Pseudomonas aeruginosa 55 (16.4%), Staphylococcus 52 (15.5%), Cándida 14 (4.2%), Enterococcus 9 (2.7%), y Acinetobacter 7 (2.1%). 60% de los aislados de Staphylococcus aureus demostró resistencia a Cefoxitin/Oxacilina (MRSA). Entre los bacilos gram negativos, las bacterias multi-resistentes fueron Pseudomonas sp (21.8%), Klebsiella sp (44.7%), Escherichia sp (19.7%).

Conclusión: La epidemiologia microbiológica y la presencia de resistencia y multi-resistencia de una nueva UCI rural en Ecuador es similar a la epidemiologia de otras unidades. Klebsiella, E coli, Pseudomonas, y S. aureus predominan. Existe nueva evidencia para la suspensión o des-escalación de antibióticos mas temprano. Utilizando herramientas como CPIS, en ciertos pacientes se puede considerar suspender antibióticos luego de 6 días de terapia. Los médicos de familia que manejan pacientes dados de alta de UCI deben saber esta nueva evidencia para minimizar el uso innecesario de antibióticos.
Reapertura de escuelas durante la pandemia de COVID-19
Authors: Gavilánez-Morales Claudia , Serrano-Arevalo Karen , Guerra Verónica , Simancas-Racines Daniel , Montesinos-Guevara Camila
Published: April 2021

El 11 de marzo del 2020 la OMS declaró pandemia de COVID-19, causada por el virus SARS-CoV-2. Como resultado, varios países implementaron medidas para evitar la propagación del virus, dentro de las cuales el cierre de los centros escolares fue una decisión común implementada a nivel mundial. La información sobre esta medida es conflictiva, varios estudios reportan que los niños tienen baja participación en la cadena de transmisión mientras que otros reportan que son vehículos de transmisión por su alta carga viral y tendencia a no ser detectados por radares epidemiológicos. Existe un impacto psicológico y social en los niños frente al cierre de escuelas, sin embargo, este factor no debe ser el único determinante en la decisión de reaperturar centros escolares. El gobierno de cada país debe medir su capacidad de control epidemiológico y de respuesta ante posibles brotes y sopesarla contra los efectos que el cierre escolar tiene en sus niños para empezar a considerar la reapertura de escuelas. Con este fin organismos internaciones proponen un listado de recomendaciones para ayudar a los países que decidan reaperturar escuelas a hacerlo tan seguro como sea posible.
Sintomatología, factores de riesgo y seroprevalencia en la poblacion pediátrica dignosticada con COVID-19
Authors: Bunces Doménica , Serrano-Arevalo Karen , Montesinos-Guevara Camila , Simancas-Racines Daniel , Félix Salazar María
Published: April 2021

El diagnóstico de COVID-19 en niños es un reto clínico especialmente para los médicos generales pues su prevalencia es menor en la infancia, la sintomatología es diversa y varía según la edad. Los niños pueden ser asintomáticos, presentar sintomatología leve o incluso llegar a tener cuadros graves como el Síndrome Inflamatorio Multisistémico. El propósito de este artículo de revisión es presentar la información científica más importante sobre seroprevalencia, cuadro clínico y factores de riesgo asociados a esta enfermedad infecciosa en la infancia con el fin de aportar al diagnóstico y manejo oportunos.
Tuberculosis Miliar en paciente con infección por COVID-19 (Doble Problema). Reporte de caso
Authors: Proaño Roberto , Morales Nydia , Cajiao David
Published: April 2021

La tuberculosis es la enfermedad infecciosa con alta mortalidad en el mundo, y endémica en Ecuador, que a la fecha registra cerca de 10 millones de personas afectadas y aproximadamente 1.5 millones de muertes hasta el 2018. (1) Al menos medio millón de personas tienen formas multidrogoresistentes (MDR), generando un tratamiento largo, costoso y tóxico. En febrero del 2020 la Organización Mundial de la Salud (OMS), designó como COVID-19 al virus que provoca el SARS CoV-2 (Síndrome respiratorio Agudo severo), causante de la pandemia que hasta la fecha se mantiene vigente a nivel mundial. Al igual que la tuberculosis, esta tiene predilección por la afectación pulmonar, que clínica y radiológicamente pueden tener similitudes al momento de la evaluación, ambas con posibles desenlaces fatales sino hay un diagnóstico y manejo adecuados a tiempo. Se presenta la evolución de una paciente hospitalizada con diagnóstico de tuberculosis miliar y coinfección por COVID-19.
El coronavirus y el estado de malestar
Authors: Herrera Diego , Troya Carlos
Published: April 2021

¿Podemos reclamar a los médicos y los pacientes por buscar engañar al sistema, en búsqueda del beneficio personal (certificados médicos para justificar cirugías estéticas, reutilizar el sistema de salud duplicando esfuerzos del mismo, buscar “agentes y medios” que adelanten una cirugía programada, “sacarse pacientes” del sistema público a sus consultorios privados), cuando las élites se saltan su turno para vacunar a sus familiares? La crisis de la pandemia desnuda la corrupción de las élites políticas y económicas, la codicia y los privilegios a nivel de naciones y dentro de las sociedades; fenómenos que no son nuevos, y que tampoco disminuyeron en la crisis, sino que se incrementaron en el último año.
COVID-19
Authors: Gaus David
Published: April 2021

Se realiza una revisión de la evidencia existente hasta el cierre de la edición, sobre las vacunas contra el Covid-19, exponiendo las plataformás que utilizan, así como los requerimientos para almacenamiento y transporte. De igual forma se analiza la gran inequidad en el acceso a estas vacunas entre los países de altos ingresos, con los países pobres, y al interior de estos últimos.

Los países desarrollados han iniciado un proceso agresivo de vacunación en sus poblaciones, olvidando que el éxito o el fracaso de las vacunas dependen de la cantidad de inmunizaciones que se logren en todo el planeta y no solo en algunos territorios.

Una encuesta realizada en el Ecuador, demuestra que el 40% de los encuestados, no están dispuestos a vacunarse, esto ejemplifica la complejidad que deben enfrentar los países latinoamericanos para superar sus limitaciones económicas, culturales y técnicas que limitan el éxito de la vacunación en las poblaciones pobres.
Thick-walled spherical shell problem
Authors: Artemov A. M. , Baranovskii E. S. , Verlin A. A. , Syomka E. V.
Published: April 2021

Introduction. Cylindrical and spherical shells are extensively used in engineering. They face internal and/or external pressure and heat. Stresses and strains distribution in elastoplastic shells has been studied by many scientists. Numerous works involve the use of the von Mises yield conditions, maximum shear stress, maximum reduced stress. These condi- tions do not include the dependence on the first invariant of the stress tensor and the sign of the third invariant of the stress deviator. In some cases, it is possible to obtain numerical-analytical solutions for stresses, displacements and de- formations for bodies with spherical and cylindrical symmetry under axisymmetric thermal and force action.

Materials and Methods. The problem on the state of a thick-walled elastoplastic shell is solved within the framework of the theory of small deformations. A plasticity condition is proposed, which takes into account the dependence of the stress tensor on three independent invariants, and also considers the sign of the third invariant of the stress deviator and translational hardening of the material. A disconnected thermoelastoplastic problem is being solved. To estimate the stresses in the region of the elastic state of a spherical shell, an equivalent stress is introduced, which is similar to the selected plasticity function. The construction of the stress vector hodograph is used as a method for verification of the stress state.

Results. The problem has an analytical solution for linear plasticity functions. A solution is obtained when the strength- ening of the material is taken into account. Analytical and graphical relationships between the parameters of external action for the elastic or elastoplastic states of the sphere are determined. For a combined load, variants are possible when the plastic region is generated at the inner and outer boundaries of the sphere or between these boundaries.

Discussion and Conclusions. The calculation results have shown that taking into account the plastic compressibility and the dependence of the plastic limit on temperature can have a significant impact on the stress and strain state of a hollow sphere. In this case, taking into account the first invariant of the stress tensor under the plasticity condition leads to the fact that not only the pressure drop between the outer and inner boundaries of the spherical shell, but the pressure values at these boundaries, can vary within a limited range. In this formulation of the problem, when there is only thermal action, the hollow sphere does not completely pass into the plastic state. The research results provide predicting the behavior of an object (a hollow sphere) that experiences centrally symmetric distributed power and thermal external influences.
Material point physical model rationale while studying kinematic characteristics of a motor vehicle in case of oblique collision with side cable barriers
Authors: Kolesnikova G. P.
Published: April 2021

Introduction. A review of the application of theoretical mechanics methods for the development of algorithms of approximate analytical simulation of a motor vehicle (MV) movement in case of oblique collision with side cable barriers is performed. The representation of the MV as a material point in this type of collision is validated. The study objective is to demonstrate the application of a physical model of a material point to describe the motor vehicle dynamics in the event of its oblique collision with side cable barrier.

Materials and Methods. A new physical model that describes the opposition to the motor vehicle movement from the side of a cable barrier in an oblique collision is proposed. New methods of approximate analytical construction of the MV movements during an oblique collision with the side cable barriers are presented. The analytical calculation results are verified by the data of the finite element (FE) simulation of the collision according to the data of field tests. The FE simulation was carried out using a multi-purpose finite element complex LS-Dyna.

Results. New analytical algorithms have been developed for the MV movement in case of an oblique collision with side cable barriers, as well as a new physical model describing the opposition to the MV movement from the side of cable barriers. The application of a physical model of a material point to study the motor vehicle dynamics during an oblique collision with side cable barriers is established scientifically, including the comparative analysis of the kinematic results of the virtual test with kinematic calculations obtained on the basis of algorithms for analytical construction of the MV movements.

Discussion and Conclusions. The analysis of the kinematic results of the virtual test in comparison with the analytical kinematic calculations has shown that the representation of a motor vehicle as a material point in case of an oblique collision with side cable barriers is reasonable since the MV movement is close to translational motion. The results obtained can be used in the development and analysis of the correctness of the FE modeling of a side collision of a motor vehicle with cable barriers.
Inverse analysis method for mathematical modeling of hydrodynamic ballast in a drilling rig
Authors: Antypas I. R. , Dyachenko A. G. , Saed B. I.
Published: April 2021

Introduction. When organizing drilling operations, one of the major problems is the accuracy and smoothness of lowering bundles of pipes into the shaft of the drilling rig. This depends on many factors, including the operation of the hydraulic brake of the lifting device. The objectives of this work are to create and study a mathematical model of hydrodynamic ballast in a drilling rig. Using the inverse analysis method, the effect of some performance indicators on the braking torque of the hydraulic brake is studied.

Materials and Methods. The experiments were performed using a laboratory setup, which is a model of a hydrobrake. Its valve was closed under various conditions to obtain several pressure values with the calculation of the braking torque when a certain weight was suspended. The real (field) operating conditions of the hydromatic brake were simulated, and the results obtained were compared. When creating a mathematical model, the inverse analysis method is used. It is based on the results of experimental measurements and provides expressing the totality of the effects of individual variables on the braking torque.

Results. A mathematical model of the hydraulic brake has been created and tested. The dependence of the braking torque on the pressure, density, and viscosity of the ballast fluid is determined. The influence of each variable is determined experimentally since the dependence under consideration cannot be represented as a direct relationship. The inverse analysis method is used to obtain a set of constant values that give the optimal solution. Taking into account the standard error array and the minimum standard error, the statistical errors made during experimental measurements are considered. The physically acceptable range of values of the proposed mathematical model is visualized. Using a basic (nonlinear) mathematical model, the auxiliary braking torque of a hydrobrake is calculated as a function of pressure, density, and viscosity. The proposed model validity is established. The calculated values of the braking torque were used as a criterion of correctness. The erroneous discrepancy did not exceed 6 %. For additional testing of the model, a computational experiment simulating field conditions was performed.

Discussion and Conclusions. For mathematical modeling of hydrodynamic ballast in a drilling rig, it is advisable to use the inverse analysis method. The model proposed in this paper relates the braking torque of a hydrobrake to the operating parameters of the fluid inside the ballast: pressure, viscosity, and density. The objectivity of the model is validated. An amendment to it is proposed to simulate the operation of the brake in the field. Based on the results obtained, in future studies it is advisable to test the created model in the field with a real payload.