bluuebunny/crossref_metadata_2025 huggingface dataset:
Bacterial communities in habitats of Dongchuan, China: Their role in slate weathering in triggering and flowing areas of debris flow
Authors: Wang Qi , Cheng Cheng , Agathokleous Evgenios , Zang Shenggang , Sheng Xiafang
Published: April 2021

Debris flow is one of the most severe disasters in China’s mountainous areas. Landslide soil materials are deposited on steep hill terrains or in channels and, once triggered by heavy rainfall, they can evolve into lethal debris flows. Some studies have suggested a prominent role of rock weathering in the formation of large landslides. In the present study, the a-diversity, composition, and weathering potential of bacterial communities inhabiting surfaces of slate rocks from the triggering area (altered less or more) and slate rocks from the flowing area of debris flows were studied. We found that a-diversity indices were positively correlated with the organic matter content, and Firmicutes accounted for about 66% of the total bacterial community. The variation in bacterial community composition was majorly driven by available Ca. The highest relative abundances of genetic families associated with organic acid production, flagellar assembly and carbonic anhydrase were found in surfaces of less-altered slate rocks from the triggering area by using PICRUSt. All the bacterial strains isolated from rock surface have the ability to accelerate the weathering of slate, among which Pantoea and Pseudomonas genera showing the highest ability to enhance the dissolutions of Fe, Si, Al, and Ca from slate. These results indicated an important role of the rock surface-inhabiting bacterial communities in the weathering of slate in both triggering and flowing areas of debris flow. This study also provides new insights into the biological characterizations of rocks in debris flow areas of Dongchuan, China.
Basic Treatment Combined With Atomized Inhalation of Amikacin for Ventilator-associated Pneumonia: A Meta-analysis of Randomized Controlled Trials
Authors: Huang Qihui , Feng Xiaojia , Guo Huihui , Zhang Lin
Published: April 2021

Background: Compared with single intravenous therapy, nebulized amikacin combined with intravenous therapy can significantly benefit ventilator-associated pneumonia (VAP). However, the existing literature provides controversial conclusions. Methods: We systematically searched PubMed, Embase, Cochrane, CNKI, VIP, and Wanfang databases (without language restriction) for randomized controlled trials (RCTs) involving atomization inhalation of amikacin in the treatment of VAP published before October 2020. Literature screening, data extraction, and quality evaluation were performed according to the preferred reporting items for systematic reviews and meta-analyses guidelines. Results : A total of 9 RCTs were found eligible and included in our analysis (1162 patients with VAP). The results of this meta-analysis showed a significant benefit of combination treatment for improving the clinical cure (odds ratio, 2.40; 95% CI, 1.50–3.84; p = 0.006), Pathogen clearance rate (odds ratio, 3.46; 95% CI, 2.41–4.97; p <0.001), bronchospasm rate (odds ratio, 2.82; 95% CI, 1.38–5.78; p = 0.005) and Clinical pulmonary Infection Score (CPIS) (MD,-0.90; 95% CI, -1.23 to -0.57; p<0.001), No significant difference was found in 28-day mortality (odds ratio, 1.15; 95%CI, 0.81–1.63; p = 0.45) and renal impairment (odds ratio, 0.88; 95% CI, 0.60–1.30; p = 0.53). Conclusion : The addition of atomization inhalation of amikacin to intravenous antibiotics treatment in VAP patients significantly improves the clinical cure rate and pathogen clearance rate, t can also help reduce the 28-day mortality, bronchospasm rate and CPIS outcome. In addition, the combination has no significant difference in the rate of renal impairment over the conventional intravenous treatment.
Sodalis Glossinidius and Wolbachia Infections in Wild Population of Glossina Morsitans Submorsitans Caught in the Area of Lake Iro in the South of Chad
Authors: Signaboubo Djoukzoumka , Payne Vincent Khan , Moussa Ibrahim Mahamat Alhaj , Mahamat Mahamat Hassane , Kanté Sartrien Tagueu , Mfopit Youssouf Mouliom , Berger Petra , Kelm Soerge , Simo Gustave
Published: April 2021

Background: To improve vector control of tsetse transmitted trypanosomiases through a better understanging of the vectorial competence of tsetse flies, investigations have been undertaken on the bacterial fauna of different tsetse species. It is in this light that Wolbachia and Sodalis glossinidius were detected in wild populations of Glossina morsistans submorsistans caught in the area of lake Iro in the south of Chad with the aim of generating data that may help to understand the influence of these symbiotic microorganisms on the vectorial competence of G. m. submorsistans. Methods: Tsetse flies were captured using biconical traps. DNA was extracted from tsetse body using the resin chelex. Sodalis glossinidius and Wolbachia were investigated by PCR using specific primers for pSG 2 and wsp genes. Comparisons between S. glossinidius and Wolbachia infections were performed according to sex and sampling periods and association studies between trypanosome infections and S. glossinidius or Wolbachia were performed. Results: From 345 G. m. submorsitans analyzed, 9.0% and 14.5% were respectively infected with S. glossinidius and Wolbachia. Only 2.31% of all tsetse flies hosted the 2 bacteria. Of all trypanosome-infected flies, 7.1% and 9.8% hosted respectively S. glossinidius and Wolbachia. No association was observed between Wolbachia and trypanosomes while significant association (r = 4.992; P = 0.025) was found between S. glossinidius and trypanosome infections. Although significant association (r = 3.147; P = 0.043) was observed between S. glossinidius and T. simiae, none was found with T. congolense or T. godfreyi. Conclusion: This study revealed S. glossinidius and Wolbachia in wild population of G. m. submorsitans of lake Iro. It showed that few tsetse flies are co-infected by Wolbachia and S. glossinidius. The presence of S. glossinidius seems to favor trypanosome infections while Wolbachia has probably no effect. Decrypting the tripartite association requires to investigate the relationship between haplotypes or genotypes of Wolbachia and/or S. glossiniduis and trypanosome infections.
Comparison of Slope Mass Ratings Classification Systems: A Review
Authors: QADRI JIBRAN , Alam M Masroor , Sadique Md Rehan
Published: April 2021

Engineering rock mass classifications are vital for empirical approach to evaluate and predict engineering behavior of a rock mass. Now well established empirical relations between behavior of the rock mass and the rock mass properties with regard to specific engineering applications have become an important tool for resolving many geo-engineering issues related to mega engineering projects. Engineering classifications of Rock Masses have been applied in tunneling and underground mining with great success for many years. Some rock mass classification systems developed originally for underground, excavations were also modified and adopted for many different applications including slope stability applications. The rocky slopes in general as well as along road and rail tracks are important locales for slope analysis and stabilization. In this study five classification systems are thoroughly studied for rock stability assessment and compared on the basis of reports of various research paper published so far. The methods are Slope Mass Rating and it’s off shoots, such as Continuous Slope Mass Rating, Chinese Slope Mass Rating, Graphical Slope Mass Rating and Landslide Hazard Evaluation Factor. We have tried to work which of these method can best predict slope failure as a normal process of mass wasting and mass movement as well as triggering mechanism such as pore water pressure increase, sudden down pour, earthquakes etc. So as to work out structurally controlled failure mechanism to find suitable ways for safe rock slope cuts for road networks in hilly and mountains terrain.
Impact of COVID-19 Pandemic on Aircraft Noise Levels, Annoyance, and Health Effects in an Urban Area in Oman
Authors: Amoatey Patrick , Al-Harthy Issa , Al-Jabri Khalifa , Al-Mamun Abdullah , Baawain Mahad Said , Al-Mayahi Ahmed
Published: April 2021

This study aimed at investigating aircraft noise exposure levels, their annoyance, and potential health effects among communities living within airport catchment areas during the COVID-19 pandemic. Both field measurements and an online survey approach were used to investigate aircraft noise exposure levels, annoyance, and general health effects among residents living near Muscat International Airport (MCT) in Muscat, Oman amid COVID-19 period. The study found a drastic decline in aircraft noise levels due to the introduction of COVID-19 intervention measures such as lock-downs, social distancing, and closure of airports. In June 2020, during the COVID-19 pandemic average daily aircraft noise levels of LAeq (39.9 dB(A)) and Lmax (49.7 dB(A)) was observed compared to the previous year (April-May 2019) of 58.5 and 76.8 dB(A), indicating aircraft noise reductions level of 32% and 35%, respectively. The results of the online social survey among 187 participants showed that most (58.8%) of the respondents did not feel that the level of noise produced by aircraft causes annoyance. During the day, the vast majority of the interviewees did not complain of any annoyance during the morning (45.5%), afternoon (39.6%), and evening (31%) with only < 4% of residents having reported a very high degree of annoyance of during COVID-19 pandemic period. Very few people (17%) did complain of experiencing general health problems while 29% did not know of any potential health effects that could be attributed to aircraft noise exposures. These findings support the need sustainable mitigation of aircraft noise in order to help improve health.
A Fabry-Pérot cavity coupled surface plasmon photodiode for electrical biomolecular sensing
Authors: Allison Giles , Sana Amrita , Ogawa Yuta , Kato Hidemi , Ueno Kosei , Misawa Hiroaki , Hayashi Koki , Suzuki Hironori
Published: April 2021

Surface plasmon resonance (SPR) is a well-established technology for real-time highly sensitive label-free detection and measurement of binding kinetics between biological samples. A common drawback, however, of SPR detection is the necessity for far field angular resolved measurement of specular reflection, which increases the size as well as requiring precise calibration of the optical apparatus. Here we present an alternative optoelectronic approach in which the plasmonic sensor is integrated within a photovoltaic cell. Incident light generates an electronic signal that is sensitive to the refractive index (RI) of a solution via interaction with the plasmon. The photogenerated current is enhanced due to the coupling of the plasmon mode with Fabry-Pérot (FP) modes in the absorbing layer of the photovoltaic cell. The near field electrical detection of SPR we demonstrate will enable a new generation of cheap, compact and high throughput biosensors.
Isotherms and thermodynamics of malachite green on CO2-activated carbon fibers
Authors: Lee Joon Hyuk , Lee Soon Hong , Suh Dong Hack
Published: April 2021

Carbonaceous adsorbents have received substantial attention in the past decades because of their porous surface characteristics. However, the majority use of strong acids for the surface modification and the subsequent surface decrease remains challenging. Here, we designed porous carbon fibers with the aid of CO2 during activation for effective malachite green (MG) adsorption. The physiochemical mechanisms have been characterized both experimentally and numerically to decipher the underlying relevance of CO2-activation on the MG adsorption capacity. The obtained samples are dominated by micropores, resulting in a high specific surface up to 1012 m2 g-1 via 60 min of CO2-activation. The adsorption isotherm was fitted to Langmuir with the maximum adsorption capacity of 555.56 mg L-1. Thermodynamics revealed endothermic in nature and the spontaneous adsorption process. By using the primary culprit of global warming, this work advances the design of carbonaceous adsorbents for cationic dye removal. (144/150)
Acceptability of the Coronavirus Disease-2019 Vaccine Among Medical Students in Uganda: a Cross Sectional Study.
Authors: Kanyike Andrew Marvin , Olum Ronald , Kajjimu Jonathan , Ojilong Daniel , Akech Grabriel Madut , Nassozi Dianah Rhoda , Agira Drake , Wamala Nicholas Kisaakye , Asiimwe Asaph , Matovu Dissan , Nakimuli Ann Babra , Lyavala Musilim , Kulwenza Patricia , Kiwumulo Joshua , Bongomin Felix
Published: April 2021

Background

COVID-19 is still a major global threat and vaccination remains the long-lasting solution. Unanimous uptake of the COVID-19 vaccine is required to subsequently avert its spread. We therefore, assessed COVID-19 vaccine acceptability, hesitancy, and associated factors among medical students in Uganda.
Methods

This study employed an online descriptive cross-sectional survey among medical students across 10 medical schools in Uganda. A structured questionnaire as a Google form was sent to participants via WhatsApp. Data was extracted and analyzed using Microsoft Excel 2016 and STATA 16. Descriptive statistics, bivariate and multivariable analyses were performed.
Results

We surveyed 600 medical students, 377 (62.8%) were male. COVID-19 vaccine hesitancy and acceptability were 30.7% and 37.3%, respectively. Factors associated with vaccine acceptability were being female (aOR = 1.9, 95% CI: 1.3–2.9, p = 0.001), being single (aOR = 2.1, 95% CI 1.1–3.9, p = 0.022). Very high (aOR = 3.5, 95% CI 1.7–6.9, p < 0.001) or moderate (aOR = 2.2, 95% CI 1.2–4.1, p = 0.008) perceived risk of getting COVID-19 in the future, receiving any vaccine in the past 5 years (aOR = 1.6, 95% CI 1.1–2.5, p = 0.017), and COVID-19 vaccine hesitancy (aOR 0.6, 95% CI 0.4–0.9, p = 0.036).
Conclusions

This study revealed low levels of acceptance towards the COVID-19 vaccine among medical students, low self-perceived risks of COVID-19, and many had relied on social media that provided them with negative information. This poses an evident risk on the battle towards COVID-19 in the future especially when these future health professions are expected to be influencing decisions of the general public towards the same.
The heterogeneous severity of COVID-19 in African countries: A modeling approach
Authors: Musa Salihu Sabiu , Wang Xueying , Zhao Shi , Li Shudong , Hussaini Nafiu , Wang Weiming , He Daihai
Published: April 2021

Background: The COVID-19 pandemic has had a considerable impact on global health and economics. The impact in African countries has not been investigated through fitting epidemic models to the reported COVID-19 deaths.Method: We downloaded data for the twelve most affected countries with the highest cumulative COVID-19 deaths to estimate the time-varying basic reproductive number (R0(t)) and infection attack rate (IAR). We developed a simple epidemic model and fitted the model to reported COVID-19 deaths in twelve African countries using iterated filtering and allowing a flexible transmission rate.Results: We observed high heterogeneity in the case-fatality rate across countries, which may be due to different reporting or testing efforts. South Africa, Tunisia, and Libya were affected most strongly, exhibiting a relatively higher(R0(t)) and infection attack rate.Conclusion: To effectively control the spread of COVID-19 epidemics in Africa, there is a need to consider other mitigation strategies (such as improvements in socioeconomic well-being, healthcare systems, the water supply, and awareness campaigns).
Study of the air environment state in the building for the storage of perishable products
Authors:   East Siberian State University of Technology and Management, Kalashnikov Michail P.
Published: April 2021

The present work is aimed at studying the formation of microclimate parameters in buildings for the storage of perishable products under the highly continental climatic conditions of the Eastern Siberia. As a result of vital microorganism processes taking place during storage periods, an intensive release of heat, moisture and carbon dioxide is observed to significantly affect the gas composition of the air mass in the volume of storage bays. The quality of short-life products in the storage is ensured by the standardisation of microclimate parameters, such as temperature, relative humidity and the composition of the internal air envi-ronment. In the storage container, a constant circulation of air flows must be ensured along with a balance of temperature determined by a certain storage mode for short-life products, which includes a separate air pas-sage to each container unit. An assessment of the management of air exchange by a general ventilation sys-tem in buildings for storing perishable products is given. The results of the air environment study during the storage of perishable products in containers are presented. The dependence of the microclimate parameters on the amount of fresh thermodynamically-treated air is determined. With an increase in the stack loading height, the air velocity is established to decrease by a factor of two (from 0.48 to 0.23 m/s), due to a signifi-cant aerodynamic drag created by the product containers. Under the normalised microclimate parameters, direct air distribution with a higher velocity (in the range from 0.2 to 0.3 m/s) both into the space between containers and directly to the perishable products ensures an increase in the storage life of products of 20–25%.
Refrigerant stabilisation as an energy-efficient solution for server microclimate maintenance
Authors:   Irkutsk National Research Technical University, Geun-Sik Ko , Tolstoy Michael Yu. ,   Irkutsk National Research Technical University
Published: April 2021

Among all known methods for energy saving based renewable energy sources, those aimed at improving the quality of equipment regulation are of particular importance. The use of renewable energy sources ensures an increase in energy saving; however, the equipment used in engineering systems should also be reliable. At present, almost every office building has a special facility for server equipment. Such facilities are rarely furnished with devices for removing excess heat, which may hinder stable operation of computer equipment and shorten its service life. In the present study, the energy efficiency of a method for stabilising the refrigerant in air conditioning systems operating on freon is experimentally verified. The stabilisation of the refrigerant is based on bringing the gas-liquid freon in the circuit to a uniform state prior to its entry in the thermostatic expansion valve (TEV). A refrigerant stabilisation device was embedded in the circuit of the on/off type split system, the working substance in which was R410A. During 3 months, the temperature of the server mobile station and the power consumption of the split system were monitored in real time, 24/7. On the basis of the obtained results, the energy saving was calculated. The test results were independent of external factors. Reasons for a more efficient cooling of the split system by bringing the refrigerant to a homogeneous state with a decrease in its temperature prior to its entry in the TEV were investigated. It is shown that, in the evaporator, freon requires more time and energy for the phase transition, which process consumes more heat from the facilities under cooling.
Study into the possibility of deriving thermal insulation materials based on peat obtained in Tyumen Oblast
Authors:   Industrial University of Tyumen, Kudomanov Maksim V. , Radaev Sergey S. ,   Industrial University of Tyumen, Selezneva Olga I. ,   Industrial University of Tyumen, Shustov Pavel A. ,   Irkutsk National Research Technical University,   Angarsk State Technical University
Published: April 2021

At present, research on expanding the raw material base for new building materials appears to be relevant. In world practice, the development of new locally-based materials takes place alongside a detailed analysis of existing deposits in order to determine possible means of their application. The present study is focused on the possibility of obtaining thermal insulation composites based on peat obtained from the Gusevskoye deposit (Tyumen Oblast) and tripoli from the Sukholozhskoye deposit (Sverdlovsk Oblast) were studied. Results of thermo gravimetric and laser diffraction granulometric analyses determining the chemical, thermal and thermo physical properties composition of the obtained raw materials are presented. Particle size was determined using a Fritsch Nano Tex laser analyser with a range of 0.01–2100 μm. A liquid glass suspension was obtained by hydrothermal leaching in order to obtain kinetic thermal decomposition parameters. Taking into account the chemical and mineralogical features of the peat from Gusevskoye deposit (Tyumen Oblast) and the tripoli from Sukholozhskoye deposit (Sverdlovsk Oblast), the liquid glass is obtained with the main component presented by opal rock. A method for producing a thermal insulation material is developed. The hydrothermal leaching method of tripoli appears to be resource-saving, less energy-consuming and, as a result, more economically feasible as compared to the classical method of liquid glass production. The resulting material is established to be environmentally-friendly and energy efficient.
Application of heat pumps in systems for maintaining the microclimate of high-rise buildings
Authors:   Irkutsk National Research Technical University, Makarov Sviatoslav S.
Published: April 2021

In the present study, the relevance of microclimate considerations in the residential premises of high-rise buildings is considered. The application of a natural exhaust ventilation system without forced air removal leads to a deterioration in the quality of the indoor air environment, including suboptimal temperature and humidity conditions, an increase in CO2 and dust concentration, as well as the development of pathogenic microorganisms. A transition from a natural ventilation system to one using air recuperative heat exchangers to reuse recyclable heat is proposed. In conditions of low winter temperatures, the prob-lem of freezing in plate heat exchangers leads to a decrease in their energy efficiency. The main content of the study for the operating air supply and exhaust unit with a plate recuperator involves an analysis of methods for preventing freezing and a comparative calculation of energy costs. Three options for pre-venting freezing are considered: the use of an electric air heater prior to the recuperator for heating air to -14 ºC (the freezing condition for this heat exchanger); the use of a bypass to defrost the heat exchanger; the use of a heat pump to transfer heat energy from the exhaust to the supply air. In the developed ex-perimental model with a heat pump, Freon R410A is used as a heat carrier. The calculated data indicate the total energy consumption at -36 ºC to comprise 20.4, 21.3 and 13.5 kW when using an electric air heater, a recuperator with a bypass and a heat pump, respectively. Additionally, the dependences of the change in relative humidity on temperature are derived. Summarising the obtained results, it is possible to use a heat pump for rationalising thermal and electric energy spent on building heating and maintain-ing the indoor microclimate.
Simulation model of a pulsed spiral hydro-mechanical energy converter in the heat supply system of a building
Authors:   National Research Ogarev Mordovia State University, Golyanin Anton A. , Levtsev Aleksey P. ,   National Research Ogarev Mordovia State University, Vdovin Anton V. ,   National Research Ogarev Mordovia State University
Published: April 2021

The objective was to develop a mathematical simulation model of a pulsed spiral hydro-mechanical flow energy converter with a variable speed operating in a pulsed mode. This simulation model can be used for calculating the optimal parameters of such devices. The mechanical energy generated by pulsed liquid can be applied in the driving gear of mini-hydroelectric generators working without drops in water pressure, pumping stations and heat networks providing pressure reduction, as well as in heater fans operating in damp or explosion-hazardous facilities. Pulsed spiral hydro-mechanical energy converters can be used for converting the energy of a liquid flow into rotational motion, which can be further transferred to an electric generator or capacitor. In this study, using the example of a hydro-mechanical converter with a cone-shaped coil, the equations of torque depending on the change in the frequency of flow interruption, the moment of inertia and the resistance in the supports were obtained. Design charts were built for the torque of a hydro-mechanical converter with a cone-shaped coil for a number of coil turns equal to 4 pcs., square tube section 0.00011 m2, and the length of the initial round 0.176 m. The validity of the equations was confirmed by a physical experiment with sufficient accuracy. The conducted comparison of simulated and experimental values showed their agreement with an error of less than 5%. According to the simulation results, design parameters for different models have their own characteristics.
Results of testing a lenticular coating block support unit
Authors:   School of Engineering and Construction of Siberian Federal University, Grigoriev Sergey V. , Palagushkin Vladimir I. ,   School of Engineering and Construction of Siberian Federal University, Petukhova Inna Y. ,   School of Engineering and Construction of Siberian Federal University, Astrakhantcev Dmitry O. ,   School of Engineering and Construction of Siberian Federal University
Published: April 2021

The paper aims to study options for connecting belt elements from a profiled sheet, to develop a technology for manufacturing support units and to determine their load-bearing capacity by testing nodal elements with connecting sheets using electric rivets and soldering pre-rolled profiled sheets. An experimental study of nodal elements was performed in a vertical position on a test bench. Fragments of the support assembly with a seam-soldered connection and with the connection of belt elements using contact spot welding were tested. It is shown that seam-soldered joints provide the necessary strength thus being suitable as a basis for the flawless manufacture of an experimental unit. For welding connection, two options of the support unit were considered, i.e. with plastic support ribs and without ribs. The junction of profiled sheets using electric rivets is more technologically advanced than a seam-soldered joint. The conducted tests elaborated the proposed design solution and the method of manufacturing the connection of profiled sheets (support units). Tests of operability, reliability and strength of this junction with various connections were carried out.
Development and current state of the regulation of the natural exposure of the public of the Russian Federation (To commemorate the 90th birthday of Professor Krisiyk E.M.). Part 1
Authors: Omelchuk V. V.
Published: April 2021

In April 2020 we commemorate the 90th birthday of the major scientist, doctor of technical sciences, Professor Eduard Mechislavovich Krisiyk. A new field of research on radiation-hygienic assessment of the natural sources of ionizing exposure and limitation of the public exposure has been developed under his scientific supervision and personal participation. For the first time in the international practice E.M. Krisiyk as the main author developed the requirements for the concentration of the natural radionuclides in the building materials; as the co-author – in phosphoric fertilizers, indicated the necessity of their radiation control. His scientific results were included into various Russian legislative and methodical documents: Federal state law “On the radiation safety of the public” in 1996, Norms of the radiation safety NRB-96 and NRB-99, Basic sanitary rules on the provision of the radiation safety OSPORB-99, Federal targeted program “Radon”, various guidelines. His scientific school, his flock and followers are successfully developing the scientific-methodical basics of the regulation of the natural exposure of the public of the Russian Federation at the current stage.
Management by objectives method in the government support arrangements for the public pharmacare system
Authors:   Ammosov North-Eastern Federal University, М.К. Russia, Yakutsk, Tarabukina S.M. , Dremova N.B. ,   Kursk State Medical University, Russia, Kursk
Published: April 2021

The article proposes an algorithm for developing an object-oriented government program to build up the public pharmacare system in the Arctic areas of the Republic of Sakha (Yakutia). The need for combined efforts and competences of professional public organizations, business entities, executive and municipal authorities to ensure the efficiency and effectiveness of this support is substantiated.
New old trends. Advertising practice
Authors:   Trubor Law Firm, Borzova Maria
Published: April 2021

Law enforcement practice in the sphere of drug advertising continues to be one of the most challenging and controversial regulatory areas. Market players develop industry guidelines, companies enact by-laws to deal with advertising materials and risk mitigation strategies. However, life always makes adjustments even to the application of well-established algorithms. Some approaches of the law enforcers get deeper roots, while others grow more and more detailed, which often needs to be reflected in the internal policies of advertisers and advertising distributors. The antimonopoly authority practice was no exception in 2020. In this regard, the article will provide a brief review of the key, in our opinion, decisions of law enforcement authorities and summarize the old and new interpretations.
Elemental Chalcogen (Se, S) in PEG-400 to the Synthesis of Seleno- and Thioflavones from 2-Chlorophenyl Ethynyl Ketone and Nucleophilic Species of Chalcogen
Authors: Nobre Patrick , Peglow Thiago , Bartz Ricardo , Barcellos Angelita , Jacob Raquel , Silva Márcio , Barcellos Thiago , Perin Gelson
Published: April 2021

An alternative green method was developed for the synthesis of thio- and selenoflavones by the ring closure of 2-chlorophenyl ethynyl ketone with NaHY (Y = S, Se). These nucleophilic chalcogen species were generated in situ using NaBH4 to reduce the elemental chalcogen in the presence of polyethylene glycol-400 (PEG-400). The efficiency of this reaction is strongly dependent on the PEG-400 solvent, acting like a crown ether, complexing with the sodium atom of NaHY species, making the chalcogen nucleophile more active. The synthetic protocol proceeded efficiently at 100 °C under argon, using a range of 2-chlorophenyl ethynyl ketone containing alkyl, aryl, or vinyl groups and the sulfur and selenium chalcogen. By this efficient and simple approach, 18 chalcogenoflavones were obtained in good to excellent yields after 2 h.
Pre-existing comorbidity, the highest risk factor for poor prognosis of COVID-19 among the Mexican population
Authors: Calixto-Calderón Basilio , Vázquez-González María F. , Martínez Peláez Rafael , Bermeo-Escalona Josué R. , García Vicente , Mena Luis J. , Maestre Gladys , Parra-Michel Jorge R. , Ceja Bravo Leobardo A. , López-de-Alba Pedro L.
Published: April 2021

The coronavirus disease 2019 (COVID-19) pandemic represents a challenge for public health and a high risk for patients with pre-existing comorbidity. As of July 20, 2020, the Case Fatality Rate (CFR) was 11.30% and the Mortality Rate (MR) was 31.28 deaths per 100,000 population. In Mexico, the prevalence of obesity, diabetes mellitus, and hypertension among the adult Mexican population is 30%, 9.2%, and 40%, respectively. The objective of this research was to identify the risk factors associated with eight comorbidities and their dependency on age for death caused by COVID-19.
Method: This study used the dataset published on July 20, 2020, by the General Directorate of Epidemiology of the Ministry of Health of Mexico. From this dataset, we analysed 130,896 positive COVID-19 cases, where 35,483 (27.107%) patients had one comorbidity, and 95,413 (72.892%) patients had not medical comorbidity. Statistical analyses include the Case Fatality Rate (CFR), the estimation of the Odds Ratio (OR), and its 95% Confidence Interval (CI).
Results: The highest CFR was 14.382% for COPD, 10.266% for CKD, 10.126% for diabetes, and 8.954% for hypertension. The obesity CFR was 3.535%. Moreover, we detected a higher risk for patients with COPD, diabetes, and CKD, resulting in OR of 4.443 (95% CI: 3.404-5.799), 3.283 (95% CI: 3.018-3.570), and 3.016 (95% CI: 2.248-4.047), respectively.
 
Conclusion: This study corroborates that the highest risk for severe disease and death caused by COVID-19 among the Mexican population are pre-existing comorbidities. Findings show that COPD, CKD, diabetes, hypertension, and cardiovascular disease increase the risk of death for patients older than 54 years. The most vulnerable age group is older than 65 years.
PET/MRI Delivers Multimodal Brain Signature in Alzheimer’s Disease with De Novo PSEN1 Mutation
Authors: Aghakhanyan Gayane , Saur Dorothee , Rullmann Michael , Weise Christopher M. , Schroeter Matthias L. , Marek Ken , Jamra Rami Abou , Tiepolt Solveig , Strauss Maria , Scherlach Cordula , Hoffmann Karl-Titus , Sabri Osama , Classen Joseph , Barthel Henryk
Published: April 2021

Background:

Little is known so far about the brain phenotype and the spatial interplay
of different Alzheimer’s disease (AD) biomarkers with structural and functional brain connectivity
in the early phase of autosomal-dominant AD (ADAD). Multimodal PET/MRI might be suitable to
fill this gap.

Material and Methods:

We presented a 31-year-old male patient without a family history of dementia
with progressive worsening of memory and motor function. Two separate sessions of 3T
PET/MRI acquisitions were arranged with the ß-amyloid tracer [18F]Florbetaben and the secondgeneration
tau tracer [18F]PI-2620. Simultaneously acquired MRI consisted of high-resolution 3D
T1, diffusion-tensor imaging (DTI), and resting-state fMRI. PET/MRI data were compared with
ten age-matched healthy controls.

Results:

Widespread β-amyloid depositions were found in cortical regions, and striatum (Thal
stage III) along with tau pathology restricted to the mesial-temporal structures (Braak stage III/IV).
Volumetric/shape analysis of subcortical structures revealed atrophy of the hippocampal-amygdala
complex. In addition, cortical thinning was detected in the right middle temporal pole. Alterations
of multiple DTI indices were noted in the major white matter fiber bundles, together with disruption
of default mode and sensory-motor network functional connectivity. Molecular genetic analysis
by next-generation sequencing revealed a heterozygote missense pathogenic variant of the
PSEN1 (Met233Val).

Conclusion:

Multimodal PET/MR imaging is able to deliver, in a one-stop-shop approach, an array
of molecular, structural and functional brain information in AD due to de novo pathogenic
variant, which can be studied for spatial interplay and might provide a rationale for initiating anti-
amyloid/tau therapeutic approaches.
Cerebrovascular Pathology and Responsiveness to Treatment in Alzheimer’s Disease: A Systematic Review
Authors: Bentham Charlotte , De Marco Matteo , Venneri Annalena
Published: April 2021

Introduction:

Responsiveness to treatment with cholinesterase inhibitors (ChEIs) is difficult to predict in Alzheimer’s disease (AD). In the current review, vascular burden is considered as a potential moderator of treatment responsiveness. Cerebrovascular burden co-occurs in at least 30% of AD brains, although it is debated if vascular pathology plays a causal or synergistic role in AD pathogenesis. Vascular burden, therefore, could potentially limit response to treatment due to limited brain reserve or foster treatment efficacy as those with vascular pathology may represent a subgroup with comparable clinical expression but less progressed AD neurodegeneration.

Methods:

A systematic search of Web of Science, Pubmed, Scopus and EthoS identified 32 papers which met the criteria for inclusion. Association of treatment response and vascular burden across five broad markers are discussed: cerebral hypoperfusion, intima-media thickness, white matter changes, cerebral microbleeds and co-existing diagnosis of cerebrovascular disease.

Results:

Analysis of frontal regional cerebral blood flow and intima-media thickness may have predictive ability to distinguish those with AD who may respond optimally to short-term treatment with ChEIs. The impact of white matter changes is less consistent; the majority of studies demonstrates no association with treatment response and those that do implicate changes in executive functioning. There is preliminary evidence that deep cerebral microbleeds limit treatment response in subcortical cognitive domains, but this finding requires replication. The use of diagnosis of co-occurring cerebrovascular disease yields no robust variability in response to ChEIs in AD.

Conclusion:

There is limited evidence that markers of cerebral hypoperfusion, intima-media thickness and cerebral microbleeds moderate response to ChEIs. Findings for other markers of vascular burden are less consistent and do not support any moderating effect.
Barbiturates: A Review of Synthesis and Antimicrobial Research Progress
Authors: Madhvi  , Utreja Divya , Sharma Shivali
Published: April 2021

Background:

Barbituric acid and its derivatives have gained significant attention for several years as
an indispensable class of compounds in the pharmaceutical industry due to their various biological activities,
such as anticonvulsants, hypnotics, anti-diabetic, antiviral, anti-AIDS, anti-cancer, anti-microbial, and antioxidant,
etc. A plethora of studies has shed light on the properties, synthesis, and reactivity of these compounds.
The depiction of multiple biological activities by barbiturates compelled us, and by virtue of which herein we
have mediated over the progress of synthesis of numerous kinds of compounds derived from barbituric acid with
well-known and typical examples from 2016 to the present.

Objective:

This review focuses on the advancements in methods of synthesis of barbituric acid derivatives and
their applications as antimicrobial agents.

Conclusion:

This review will help future researchers to analyze the previous studies and explore new compounds
for the development of efficient antimicrobial drugs.
Periacetabular Pelvic Osteotomy in Treatment of Patients with Developmental Dysplasia of the Hip
Authors: Korytkin A. A. , Novikova Ya. S. , El moudni Yo. M. , Kovaldov K. A. , Gerasimov S. A. , Gubina E. V.
Published: April 2021

Background. Pelvic osteotomies are widely used for treatment of young active patients with developmental dysplasia of the hip (DDH) Type I according to the Crowe or type A according to Hartofilakidis classifications and the absence of severe degenerative cartilage lesions. Nowadays, Ganz periacetabular osteotomy (PAO) is the most common choice of surgeons around the world in treatment of such patients.The aim of the study was to evaluate the radiological and functional results of Ganz periacetabular osteotomy in patients with DDH.Material and Methods. A single-center retrospective analysis of 49 Ganz PAO was performed in 43 patients aged 36±9 years. The radiological evaluation criteria were Wiberg (AW), Lequesne (AL), Tonnis (AT) angles, and joint medialization. The results of treatment were evaluated using the Harris scale, iHOT-12, and VAS before treatment and 1 year after, the presence of complications was also monitored.Results. The average follow-up period was 35±15 months (from 1.0 to 6.9 years). Radiological parameters improved after surgery compared to preoperative ones: AW +19.9° (17.1° vs. 37.0°), AT -11.5° (19.9° vs. 8.4°), AL +14.1° (25.1° vs. 39.2°), joint medialization -5.5 mm (14.3 mm vs. 8.8 mm) (p0.001). Functional results and quality of life of patients also improved: the Harris scale +35.6 points (47 vs 83 points), iHOT-12 +40.9 points (44 vs 85 points), pain level -2.8 points (5 vs 2 points) (p0.001). Various complications developed in 20 out of 49 cases (40.8%). Neurological complications were resolved conservatively (22.4%). A direct correlation was evaluated between the surgical treatment of DDH in childhood and the development of neurological complications after PAO (R = 0.76; p0.001). In 9 cases out of 49 (18.4%), revision surgery was required: in 3 — total hip replacement, in 2 — reorientation of the acetabulum, in 4 — arthroscopic fixation of the anterior articular lip. In 93.9% of cases native hip joint surfaces were preserved.Conclusion. Ganz PAO has good reconstructive capabilities and sufficient efficiency. The operation allows to restore the coverage of the femoral head with the acetabulum, delays total hip replacement and provides improved functional results.
Improvement of Perioperative Management of Patients Undergoing Surgical Treatment for Hip Periprosthetic Joint Infection
Authors: Kochish A. A. , Bozhkova S. A. , Artyukh V. A. , Liventsov V. N. , Afanas’ev A. V. , Toropov S. S.
Published: April 2021

Two-stage revision arthroplasty in chronic hip periprosthetic joint infection cases is the “gold standard” treatment. First stage debridement leads to large intraoperative and drainage blood loss using standard protocols for thromboprophylaxis and drainage of the surgical wound, which is a significant disadvantage of perioperative management of such patients.The aim of the study was to determine the effect of modified management protocol with delayed start of thromboprophylaxis and a short period of drainage on the blood loss and the effectiveness of debridement with antibiotic-impregnated spacer placement in patients with hip periprosthetic joint infection.Materials and Methods. A single-center prospective study was conducted. 90 patients underwent endoprosthesis components removal and antibiotic-impregnated spacer placement. Patients were divided into 3 groups: start of thromboprophylaxis before surgery and 3–4 days of drainage; start of thromboprophylaxis no earlier than 12 hours after surgery and 3–4 days of drainage; start of thromboprophylaxis no earlier than 12 hours after surgery and 1 day of drainage.Results. There was a statistically significant (p0.05) decrease of drainage and total blood loss, and transfused blood volume in cases with the delayed start of thromboprophylaxis and a short period of drainage. The proposed protocol was safe for prevention of venous thromboembolic complications and did not affect the frequency of periprosthetic hip joint infection recurrence. The effectiveness of the first stage of treatment — 89%, the second stage — 99% in 1 year after rehabilitation according to the second international consensus on musculoskeletal infection criteria.Conclusion. The modified protocol of perioperative management is an effective and safe as a blood-saving strategy and can be proposed for widespread use.
In Vitro Evaluation of the Allogeneic Bone Matrix Effect on the Adipose Mesenchymal Stromal Cells Characteristics in Combined Tissue Engineering
Authors: Cherdantseva L. A. , Anastasieva E. A. , Aleynik D. Ya. , Egorikhina M. N. , Kirilova I. A.
Published: April 2021

The aim of the study was to evaluate in vitro the effect of native and deproteinized compact and spongy allogenic bone matrices on the characteristics of adipose mesenchymal stromal cells (ASC) in combined tissue engineering.Material and Methods. 24 samples of native and deproteinized compact and spongy bone were examined, which were exposed to mechanical treatment, modeling, followed by sterilization of the samples by ionizing radiation and bacteriological control of sterilization. Some of the samples underwent deproteinization. The characterized cultures of human ASC were used as test cultures to assess the interaction with the bone samples. The Cytation-5 fluorescent imager and Hoechst 3334 fluorochromes (BD Pharmingen™) and calcein (Calcein AM, BD Pharmingen™) were used to characterize the degree of adhesion, migration, and viability of ASC on bone matrix samples. Matrix cytotoxicity was evaluated by MTT assay on days 1 and 7 of extraction.Results. The bone matrix samples are characterized by the absence of cytotoxicity (rank 1). ASC demonstrated good adhesion and migration on any surface of the bone matrix and preservation of cell viability during 7 days of observation. Nuclei sizes of the cells adhered to the deproteinized bone matrix of the spongy structure increased by 25–30% compared to other samples. The cells on deproteinized bone matrix had greater size (the size of the cells from nuclei 8.8 to 11.5 μm, the average size of cells nuclei from an 86.3 μm to 129,0 μm, the average perimeter of the cells nuclei from 30.7 μm to 40.7 μm) than in the native bone matrix samples.Conclusion. The results of the study of various allogeneic bone matrices demonstrate that deep purification of the bone matrix determines the absence of cytotoxicity and the most favorable conditions for the adhesion, migration, proliferation and viability of ASC. Also makes it possible to use tissue engineering based on bone matrices of different structures. Deproteinized spongy bone matrices are best suited for this purpose.
Treatment of Femoral Non-Union with the Gene-Activated Osteoplastic Material: А Case Report
Authors: Khominets V. V. , Deev R. V. , Kudyashev A. L. , Mikhailov S. V. , Shakun D. A. , Komarov A. V. , Bozo I. Yu. , Schukin A. V. , Foos I. V.
Published: April 2021

Background. Non-unions of distal femur fractures are difficult to treat and occur in about 6% of cases. Multifactorial causes of fractures non-unions require individual treatment for each patient in accordance with the “diamond” concept. The standard protocol for patients with atrophic non-unions treatment involves bone autografts using, but there are limitations of size, shape, quality and quantity of autografts. Osteoplastic materials with osteoinductive (angiogenic) and osteoconductive activity can be used as bioresorbable implants in combination with autogenous spongy bone in the treatment of extremities long bones non-unions.Clinical case description. A 63-year-old patient was admitted to the clinic for non-union of distal third of the femur with bone defect, fragments were fixed with a plate. The examination revealed plate fracture, screws migration (group III according to the Non-Union Scoring System). The volume of supposed bone defect was about 8.5 cm3. The surgery was performed: plate removal, debridement of the non-union zone, femur defect replacement with a bone autograft in combination with the gene-activated osteoplastic material “Histograft” in a ratio of 1:1, osteosynthesis of the femur with two plates. After 6 months. during the control computed tomography, consolidation was determined (4 points on the REBORNE scale). Pain was practically absent (NRS-2). The range of motion in the knee joint: flexion — 80o, extension — 180o. According to the Knee Society Score (KSS) — 68 points.Conclusion. In this case report the complete fracture fusion was achieved in patient within 6 months — 4 points on the REBORNE scale. No adverse events were observed. It confirms the safety and efficacy of described method and allows to continue the clinical trials.