bluuebunny/crossref_metadata_2025 huggingface dataset:
On-field phenotypic evaluation of sunflower populations for broad-spectrum resistance to Verticillium leaf mottle and wilt
Authors: Montecchia Juan F. , Fass Mónica I. , Cerrudo Ignacio , Quiroz Facundo J. , Nicosia Salvador , Maringolo Carla A. , Di Rienzo Julio , Troglia Carolina , Hopp H. Esteban , Escande Alberto , González Julio , Álvarez Daniel , Heinz Ruth A. , Lia Verónica V. , Paniego Norma B.
Published: June 2021

Sunflower Verticillium Wilt and Leaf Mottle (SVW), caused by Verticillium dahliae (Kleb.; Vd), is a soil-borne disease affecting sunflower worldwide. A single dominant locus, known as V1, was formerly effective in controlling North-American Vd races, whereas races from Argentina, Europe and an emerging race from USA overcome its resistance. This emphasizes the need for identifying broad-spectrum genetic resistance (BSR) sources. Here we characterize two sunflower mapping populations (MPs) for SVW resistance: a biparental MP and the association MP from the National Institute of Agricultural Technology (INTA), under field growing conditions. Nine field-trials (FTs) were conducted in highly infested fields in the most SVW-affected region of Argentina. Several disease descriptors (DDs), including incidence and severity, were scored across four phenological stages. Generalized linear models were fitted according to the nature of each variable, adjusting mean phenotypes for inbred lines across and within FTs. Comparison of these responses allowed the identification of novel BSR sources. Furthermore, we present the first report of SVW resistance heritability, with estimates ranging from 35 to 45% for DDs related to disease incidence and severity, respectively. This study constitutes the largest SVW resistance characterization reported to date in sunflower, identifying valuable genetic resources for BSR-breeding to cope with a pathogen of increasing importance worldwide.
Trigonal quasicrystalline states in $$30^\circ$$ rotated double moiré superlattices
Authors: Crosse J. A. , Moon Pilkyung
Published: June 2021

We study the lattice configuration and electronic structure of a double moiré superlattice, which is composed of a graphene layer encapsulated by two other layers in a way such that the two hexagonal moiré patterns are arranged in a dodecagonal quasicrystalline configuration. We show that there are between 0 and 4 such configurations depending on the lattice mismatch between graphene and the encapsulating layer. We then reveal the resonant interaction, which is distinct from the conventional 2-, 3-, 4-wave mixing of moiré superlattices, that brings together and hybridizes twelve degenerate Bloch states of monolayer graphene. These states do not fully satisfy the dodecagonal quasicrystalline rotational symmetry due to the symmetry of the wave vectors involved. Instead, their wave functions exhibit trigonal quasicrystalline order, which lacks inversion symmetry, at the energies much closer to the charge neutrality point of graphene.
Reconstruction of circRNA-miRNA-mRNA associated ceRNA networks reveal functional circRNAs in intracerebral hemorrhage
Authors: Liu Zhen , Wu Xinran , Yu Zihan , Tang Xiaobo
Published: June 2021

Circular RNA (circRNA), a novel class of noncoding RNAs, has been used extensively to complement transcriptome remodeling in the central nervous system, although the genomic coverage provided has rarely been studied in intracerebral hemorrhage (ICH) and is limited and fails to provide a detailed picture of the cerebral transcriptome landscape. Here, we described sequencing-based transcriptome profiling, providing comprehensive analysis of cerebral circRNA, messenger RNA (mRNA) and microRNA (miRNA) expression in ICH rats. In the study, male Sprague–Dawley rats were subjected to ICH, and next-generation sequencing of RNAs isolated from non-hemorrhagic (Sham) and hemorrhagic (ICH) rat brain samples collected 7 (early phase) and 28 (chronic phase) days after insults, was conducted. Bioinformatics analysis was performed to determine miRNA binding sites and gene ontology of circRNAs, target genes of miRNAs, as well as biological functions of mRNAs, altered after ICH. These analyses revealed different expression profiles of circRNAs, mRNAs and miRNAs in day-7 and day-28 ICH groups, respectively, compared with the Sham. In addition, the expression signature of circRNAs was more sensitive to disease progression than that of mRNAs or miRNAs. Further analysis suggested two temporally specific circRNA-miRNA-mRNA networks based on the competitive endogenous RNA theory, which had profound impacts on brain activities after ICH. In summary, these results suggested an important role for circRNAs in the pathogenesis of ICH and in reverse remodeling based on self-protection support, providing deep insights into diverse possibilities for ICH therapy through targeting circRNAs.
Expedient assessment of post-infarct remodeling by native cardiac magnetic resonance imaging in mice
Authors: Lang Cajetan Immanuel , Vasudevan Praveen , Döring Piet , Gäbel Ralf , Lemcke Heiko , Lindner Tobias , Steinhoff Gustav , Krause Bernd Joachim , Vollmar Brigitte , Meinel Felix G. , Yücel Seyrani , Öner Alper , Ince Hüseyin , David Robert
Published: June 2021

Novel therapeutic strategies aiming at improving the healing process after an acute myocardial infarction are currently under intense investigation. The mouse model plays a central role for deciphering the underlying mechanisms on a molecular and cellular level. Therefore, we intended to assess in-vivo post-infarct remodeling as comprehensively as possible using an expedient native magnetic resonance imaging (MRI) in the two most prominent infarct models, permanent ligation (PL) of the left anterior descending artery (LAD) versus ischemia reperfusion (I/R). Mice were subjected to either permanent or transient (45 min) occlusion of the LAD. After 3 weeks, examinations were performed with a 7-Tesla small animal MRI system. Data analysis was performed with the freely available software Segment. PL resulted in a massive dilation of the left ventricle, accompanied by hypertrophy of the non-infarcted myocardium and a decline of contractile function. These effects were less pronounced following I/R compared to healthy animals. Single plane assessments were not sufficient to capture the specific differences of left ventricular (LV) properties between the two infarct models. Bulls-eye plots were found to be an ideal tool for qualitative LV wall assessment, whereas a multi-slice sector-based analysis of wall regions is ideal to determine differences in hypertrophy, lateral wall thinning and wall thickening on a quantitative level. We combine the use of polar map-based analysis of LV wall properties with volumetric measurements using simple CINE CMR imaging. Our strategy represents a versatile and easily available tool for serial assessment of the LV during the remodeling process. Our study contributes to a better understanding of the effects of novel therapies targeting the healing of damaged myocardium.
Setd4 controlled quiescent c-Kit+ cells contribute to cardiac neovascularization of capillaries beyond activation
Authors: Xing Sheng , Tian Jin-Ze , Yang Shu-Hua , Huang Xue-Ting , Ding Yan-Fu , Lu Qian-Yun , Yang Jin-Shu , Yang Wei-Jun
Published: June 2021

Blood vessels in the adult mammal exist in a highly organized and stable state. In the ischemic heart, limited expansion capacity of the myocardial vascular bed cannot satisfy demands for oxygen supply and the myocardium eventually undergoes irreversible damage. The predominant contribution of endogenous c-Kit+ cells is understood to be in the development and homeostasis of cardiac endothelial cells, which suggests potential for their targeting in treatments for cardiac ischemic injury. Quiescent cells in other tissues are known to contribute to the long-term maintenance of a cell pool, preserve proliferation capacity and, upon activation, facilitate tissue homeostasis and regeneration in response to tissue injury. Here, we present evidence of a Setd4-expressing quiescent c-Kit+ cell population in the adult mouse heart originating from embryonic stages. Conditional knock-out of Setd4 in c-Kit-CreERT2;Setd4f/f;Rosa26TdTomato mice induced an increase in vascular endothelial cells of capillaries in both neonatal and adult mice. We show that Setd4 regulates quiescence of c-Kit+ cells by the PI3K-Akt-mTOR signaling pathway via H4K20me3 catalysis. In myocardial infarction injured mice, Setd4 knock-out resulted in attenuated cardiomyocyte apoptosis, decreased infarction size and improved cardiac function. Lineage tracing in Setd4-Cre;Rosa26mT/mG mice showed that Setd4+ cells contribute to each cardiac lineage. Overall, Setd4 epigenetically controls c-Kit+ cell quiescence in the adult heart by facilitating heterochromatin formation via H4K20me3. Beyond activation, endogenous quiescent c-Kit+ cells were able to improve cardiac function in myocardial infarction injured mice via the neovascularization of capillaries.
Association of the transthyretin variant V122I with polyneuropathy among individuals of African ancestry
Authors: Parker Margaret M. , Damrauer Scott M. , Tcheandjieu Catherine , Erbe David , Aldinc Emre , Hawkins Philip N. , Gillmore Julian D. , Hull Leland E. , Lynch Julie A. , Joseph Jacob , Ticau Simina , Flynn-Carroll Alexander O. , Deaton Aimee M. , Ward Lucas D. , Assimes Themistocles L. , Tsao Philip S. , Chang Kyong-Mi , Rader Daniel J. , Fitzgerald Kevin , Vaishnaw Akshay K. , Hinkle Gregory , Nioi Paul
Published: June 2021

Hereditary transthyretin-mediated (hATTR) amyloidosis is an underdiagnosed, progressively debilitating disease caused by mutations in the transthyretin (TTR) gene. V122I, a common pathogenic TTR mutation, is found in 3–4% of individuals of African ancestry in the United States and has been associated with cardiomyopathy and heart failure. To better understand the phenotypic consequences of carrying V122I, we conducted a phenome-wide association study scanning 427 ICD diagnosis codes in UK Biobank participants of African ancestry (n = 6062). Significant associations were tested for replication in the Penn Medicine Biobank (n = 5737) and the Million Veteran Program (n = 82,382). V122I was significantly associated with polyneuropathy in the UK Biobank (odds ratio [OR] = 6.4, 95% confidence interval [CI] 2.6–15.6, p = 4.2 × 10−5), which was replicated in the Penn Medicine Biobank (OR = 1.6, 95% CI 1.2–2.4, p = 6.0 × 10–3) and Million Veteran Program (OR = 1.5, 95% CI 1.2–1.8, p = 1.8 × 10−4). Polyneuropathy prevalence among V122I carriers was 2.1%, 9.0%, and 4.8% in the UK Biobank, Penn Medicine Biobank, and Million Veteran Program, respectively. The cumulative incidence of common hATTR amyloidosis manifestations (carpal tunnel syndrome, polyneuropathy, cardiomyopathy, heart failure) was significantly enriched in V122I carriers compared with non-carriers (HR = 2.8, 95% CI 1.7–4.5, p = 2.6 × 10−5) in the UK Biobank, with 37.4% of V122I carriers having at least one of these manifestations by age 75. Our findings show that V122I carriers are at increased risk of polyneuropathy. These results also emphasize the underdiagnosis of disease in V122I carriers with a significant proportion of subjects showing phenotypic changes consistent with hATTR amyloidosis. Greater understanding of the manifestations associated with V122I is critical for earlier diagnosis and treatment.
Distinction between electron states formed at topological insulator interfaces with the trivial phase and vacuum
Authors: Kazakov A. S. , Galeeva A. V. , Artamkin A. I. , Ikonnikov A. V. , Ryabova L. I. , Dvoretsky S. A. , Mikhailov N. N. , Bannikov M. I. , Danilov S. N. , Khokhlov D. R.
Published: June 2021

In this paper, we show that electron states formed in topological insulators at the interfaces topological phase–trivial phase and topological phase–vacuum may possess different properties. This is demonstrated on an example of heterostructures based on thick topological Hg1−xCdxTe films, in which the PT-symmetric terahertz photoconductivity is observed. It is shown that the effect originates from features of the interface topological film–trivial buffer/cap layer. The PT-symmetric terahertz photoconductivity is not provided by electron states formed at the interface topological film–vacuum.
Confirming putative variants at ≤ 5% allele frequency using allele enrichment and Sanger sequencing
Authors: Yan Yan Helen , Chen Sherry X. , Cheng Lauren Y. , Rodriguez Alyssa Y. , Tang Rui , Cabrera Karina , Zhang David Yu
Published: June 2021

Whole exome sequencing (WES) is used to identify mutations in a patient’s tumor DNA that are predictive of tumor behavior, including the likelihood of response or resistance to cancer therapy. WES has a mutation limit of detection (LoD) at variant allele frequencies (VAF) of 5%. Putative mutations called at ≤ 5% VAF are frequently due to sequencing errors, therefore reporting these subclonal mutations incurs risk of significant false positives. Here we performed ~ 1000 × WES on fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tissue biopsy samples from a non-small cell lung cancer patient, and identified 226 putative mutations at between 0.5 and 5% VAF. Each variant was then tested using NuProbe NGSure, to confirm the original WES calls. NGSure utilizes Blocker Displacement Amplification to first enrich the allelic fraction of the mutation and then uses Sanger sequencing to determine mutation identity. Results showed that 52% of the 226 (117) putative variants were disconfirmed, among which 2% (5) putative variants were found to be misidentified in WES. In the 66 cancer-related variants, the disconfirmed rate was 82% (54/66). This data demonstrates Blocker Displacement Amplification allelic enrichment coupled with Sanger sequencing can be used to confirm putative mutations ≤ 5% VAF. By implementing this method, next-generation sequencing can reliably report low-level variants at a high sensitivity, without the cost of high sequencing depth.
Nano-FTIR spectroscopic identification of prebiotic carbonyl compounds in Dominion Range 08006 carbonaceous chondrite
Authors: Yesiltas Mehmet , Glotch Timothy D. , Sava Bogdan
Published: June 2021

Meteorites contain organic matter that may have contributed to the origin of life on Earth. Carbonyl compounds such as aldehydes and carboxylic acids, which occur in meteorites, may be precursors of biologically necessary organic materials in the solar system. Therefore, such organic matter is of astrobiological importance and their detection and characterization can contribute to the understanding of the early solar system as well as the origin of life. Most organic matter is typically sub-micrometer in size, and organic nanoglobules are even smaller (50–300 nm). Novel analytical techniques with nanoscale spatial resolution are required to detect and characterize organic matter within extraterrestrial materials. Most techniques require powdered samples, consume the material, and lose petrographic context of organics. Here, we report the detection of nanoglobular aldehyde and carboxylic acids in a highly primitive carbonaceous chondrite (DOM 08006) with ~ 20 nm spatial resolution using nano-FTIR spectroscopy. Such organic matter is found within the matrix of DOM 08006 and is typically 50–300 nm in size. We also show petrographic context and nanoscale morphologic/topographic features of the organic matter. Our results indicate that prebiotic carbonyl nanoglobules can form in a less aqueous and relatively elevated temperature-environment (220–230 °C) in a carbonaceous parent body.
A 16-year prospective cohort study to evaluate effects of long-term fluctuations in obesity indices of prediabetics on the incidence of future diabetes
Authors: Safari Shahla , Abdoli Maryam , Amini Masoud , Aminorroaya Ashraf , Feizi Awat
Published: June 2021

This study aimed to evaluate the patterns of changes in obesity indices over time in prediabetic subjects and to classify these subjects as either having a low, moderate, and high risk for developing diabetes in the future. This study was conducted among 1228 prediabetics. The patterns of changes in obesity indices based on three measurements including first, mean values during the follow-up period, and last visit from these indices were evaluated by using the latent Markov model (LMM). The mean (standard deviation) age of subjects was 44.0 (6.8) years and 73.6% of them were female. LMM identified three latent states of subjects in terms of change in all anthropometric indices: a low, moderate, and high tendency to progress diabetes with the state sizes (29%, 45%, and 26%), respectively. LMM showed that the probability of transitioning from a low to a moderate tendency to progress diabetes was higher than the other transition probabilities. Based on a long-term evaluation of patterns of changes in obesity indices, our results reemphasized the values of all five obesity indices in clinical settings for identifying high-risk prediabetic subjects for developing diabetes in future and the need for more effective obesity prevention strategies.
Dietary dihydromyricetin supplementation enhances antioxidant capacity and improves lipid metabolism in finishing pigs
Authors: Guo Zhongyang , Chen Xiaoling , Huang Zhiqing , Chen Daiwen , Yu Bing , Chen Hong , Yu Jie , Yan Hui , Zheng Ping , Luo Yuheng
Published: June 2021

Dietary dihydromyricetin supplementation improves the antioxidant capacity and lipid metabolism in finishing pigs.
Dynamic loading enhances chondrogenesis of human chondrocytes within a biodegradable resilient hydrogel
Authors: Xie Mingsheng , Fritch Madalyn , He Yuchen , Fu Huikang , Hong Yi , Lin Hang
Published: June 2021

Dynamic loading promotes robust chondrogenesis of human chondrocytes within a resilient hydrogel.
Visible-light-induced 4CzIPN/LiBr system: a tireless electron shuttle to enable reductive deoxygenation of N-heteroaryl carbonyls
Authors: Zhong Shuai , Deng Guo-Jun , Dai Zhiqi , Huang Huawen
Published: June 2021

A mild visible-light-induced photoredox system was found to be a tireless electron shuttle to enable reductive deoxygenation of N-heteroaryl carbonyls.
Egyptian blue: from pigment to battery electrodes
Authors: Tyler J. Landon , Sacci Robert L. , Ning Jinliang , Mullins David R. , Liang Kun , Nanda Jagjit , Sun Jianwei , Naguib Michael
Published: June 2021

Herein we report on using a well known pigment that was used by ancient Egyptians and called Egyptian blue as an anode material for Li-ion batteries (background photo by Kokhanchikov via Adobe Stock).
Thermodynamically stable structure of hydroxy alkane sulfonate surfactant monomers in water achieving high water solubility and a low CMC
Authors: Tabuchi Yukiko , Sakai Takaya
Published: June 2021

This highly fixed molecular structure of this aninonic surfactant (C16-4S-5OH) in water achieves a low Krafft point and a low CMC simultaneously both of which are necessary for a modern sustainable surfactant.
Two-dimension on two-dimension growth: hierarchical Ni0.2Mo0.8N/Fe-doped Ni3N nanosheet array for overall water splitting
Authors: Liu Chen , Zhu Han , Lu Shuanglong , Xu Fangping , Duan Fang , Du Mingliang
Published: June 2021

Design of two-dimension on two-dimension growth of hierarchical Ni0.2Mo0.8N nanosheets on Fe-doped Ni3N nanosheets supported on Ni foam.
Improved liquid–liquid extraction by modified magnetic nanoparticles for the detection of eight drugs in human blood by HPLC-MS
Authors: Yang Feiyu , Ma Ke , Cao Yu , Ni Chunfang
Published: June 2021

High-performance magnetic Fe3O4@TiO2, nanospheres with mesoporous structures was synthesized for cleanup phosphatidic acid and fatty acids in blood sample for 8 drugs test with HPLC-MS.
Copolymers of bipyridinium and metal (Zn & Ni) porphyrin derivatives; theoretical insights and electrochemical activity towards CO2
Authors: Kochrekar Sachin , Kalekar Ajit , Mehta Shweta , Damlin Pia , Salomäki Mikko , Granroth Sari , Meltola Niko , Joshi Kavita , Kvarnström Carita
Published: June 2021

Electropolymerization of keto functionalized porphyrins and 4,4′-bipyridine.
A pH-sensitive, stimuli-responsive, superabsorbent, smart hydrogel from psyllium (Plantago ovata) for intelligent drug delivery
Authors: Irfan Jaffar , Hussain Muhammad Ajaz , Haseeb Muhammad Tahir , Ali Arshad , Farid-ul-Haq Muhammad , Tabassum Tahira , Hussain Syed Zajif , Hussain Irshad , Naeem-ul-Hassan Muhammad
Published: June 2021

Herein, we report the dynamic swelling, stimuli responsive swelling-deswelling properties, sub-acute toxicity studies and sustained drug release potential of a polysaccharide-based hydrogel isolated from psyllium husk (a well-known dietary fiber).
Measurement of CO2 diffusion coefficients in both bulk liquids and carven filling porous media of fractured-vuggy carbonate reservoirs at 50 MPa and 393 K
Authors: Wang Zhixing , Hou Jirui
Published: June 2021

Herein, the pressure decay method was improved to obtain the CO2 diffusion coefficient in fractured-vuggy carbonate reservoirs at 393 K and 50 MPa and obtained good correlation results between bulk and porous media by porosity and tortuosity.
A highly selective “turn-on” water-soluble fluorescent sensor for gallium ion detection
Authors: Wang Pengfei , Meng Fanda , Su Hao , Liu Lijie , Khan Maroof Ahmad , Li Hui
Published: June 2021

In this work, a highly selective water-soluble “turn-on” fluorescent sensor for gallium ion recognition was reported.
Blue-emissive two-component supergelator with aggregation-induced enhanced emission
Authors: Chandrasekharan Swathi Vanaja , Krishnan Nithiyanandan , Atchimnaidu Siriki , Raj Gowtham , P. K. Anusree Krishna , Sagar Soumya , Das Suresh , Varghese Reji
Published: June 2021

Design of a novel class of two-component, highly emissive, low molecular weight supergelator is reported.
Interfacial electronic structure modulation enables CoMoOx/CoOx/RuOx to boost advanced oxygen evolution electrocatalysis
Authors: Wang Cheng , Shang Hongyuan , Wang Yuan , Xu Hui , Li Jie , Du Yukou
Published: June 2021

A facile two-step cation exchange method has been proposed for the synthesis of CoMoRuOx nanoboxes with rich nanointerfaces, oxygen vacancies, and modulated electronic structure to enable a highly efficient OER electrolysis.
Dual-stage K+ ion intercalation in V2O5-conductive polymer composites
Authors: Charles Daniel S. , Guo Fenghua , Shan Xiaoqiang , Kim SaeWon , Lebens-Higgins Zachary W. , Xu Wenqian , Su Dong , Piper Louis F. J. , Teng Xiaowei
Published: June 2021

Dual-stage K-ion insertion in vanadium oxide was reported. K-ions are first inserted into interlayers via pseudocapacitive intercalation and then inserted into the [VO6] bi-layer (intralayer) via diffusion-limited intercalation.
FeF3·0.33H2O@carbon nanosheets with honeycomb architectures for high-capacity lithium-ion cathode storage by enhanced pseudocapacitance
Authors: Zhang Liguo , Yu Litao , Li Oi Lun , Choi Si-Young , Saeed Ghuzanfar , Kim Kwang Ho
Published: June 2021

FeF3·0.33H2O@CNS (Honeycomb-like Carbon Nanosheets) with high pseudocapacitive contribution demonstrates excellent rate and cycle performance as Li-ion cathode materials.
Chemical tuning of molecular quantum materials κ-[(BEDT-TTF)1−x(BEDT-STF)x]2Cu2(CN)3: from the Mott-insulating quantum spin liquid to metallic Fermi liquid
Authors: Saito Yohei , Rösslhuber Roland , Löhle Anja , Sanz Alonso Miriam , Wenzel Maxim , Kawamoto Atsushi , Pustogow Andrej , Dressel Martin
Published: June 2021

The electronic properties of molecular conductors are varied by substituting ions with extended wave functions to enlarge the bandwidth W. This enables them to cross the Mott insulator-to-metal phase transition by reducing electronic correlations U/W.
Cocrystal engineering of molecular rearrangement: a “turn-on” approach for high-performance N-type organic semiconductors
Authors: Wang Wei , Luo Lixing , Lin Zongqiong , Mu Zifeng , Ju Zhengkun , Yang Bo , Li Yang , Lin Menglu , Long Guankui , Zhang Jing , Zhao Jianfeng , Huang Wei
Published: June 2021

From TCAF to binary α-phase cocrystals, an electron mobility of 0.06 cm2 V−1 s−1 was found. Then by molecular rearrangement, β-cocrystals from heterogeneous nucleation growth showed a remarkable mobility up to 0.88 cm2 V−1 s−1.
Interpenetrating PAA-PEDOT conductive hydrogels for flexible skin sensors
Authors: Fu Fanfan , Wang Jilei , Yu Jing
Published: June 2021

Conductive hydrogels are promising material candidates in artificial skin and muscles, flexible and implantable bioelectronics, and tissue engineering.
Purely organic phosphorescent organic light emitting diodes using alkyl modified phenoselenazine
Authors: Kim Cho Long , Jeong Jinhoon , Jang Ho Jin , Lee Kyung Hyung , Kim Seoung-Tae , Baik Mu-Hyun , Lee Jun Yeob
Published: June 2021

Purely organic phosphorescent emitters have been developed with the incorporation of alkyl substituents into the N-phenylphenoselenazine core.
Saturated adaptive barrier sliding mode control with state‐dependent uncertainty limit
Authors: Ma Haifeng , Liu Weixiang , Li Yangmin , Liu Zhanqiang , Tian Sukun
Published: June 2021

This paper proposed a saturated adaptive barrier sliding mode control (SABSMC) for disturbed systems with parameter uncertainty, external disturbance, and input saturation. One distinctive feature of the proposed method is that even under the influence of input saturation, it is able to drive the system trajectory into a prespecified neighbourhood of the sliding surface, independent of the upper limit of lumped disturbance. Moreover, attributing to the designed adaptive laws, the switching gain of the proposed method can be adaptively adjusted in a wise manner. Another attractive feature of the proposed method is that it removes any presumption of constant upper limit on the lumped disturbance. Instead, SABSMC utilises a more rational state‐dependent upper limit assumption. The system dynamics of the closed‐loop system is analysed via the Lyapunov method in the presence of parameter uncertainty, external disturbance, and input saturation. The effectiveness of the proposed method is confirmed through numerical simulations.
Backfill mixtures based on industrial waste
Authors: Rakhimov Shavkat , Gaziev Uchqun , Babakulova Nilufar , Khudoynazarova Qunduz
Published: June 2021

The object of the study is filling mixtures based on waste from the mining, energy, and copper-smelting industries, Portland cement, and superplasticizer. In the course of the study, standardized methods for studying the properties and quality indicators of industrial waste and filling mixtures based on it and mathematical methods for optimizing the compositions of mixtures, statistical methods for analyzing the results of experiments, were used. It has been established that, in terms of their physical and mechanical characteristics, stowing mixtures based on waste are not inferior to mixtures based on natural materials. The mathematical method for planning experiments has revealed the dependences linking strength with the quantitative characteristics of the components of the filling mixture. Based on the established regularities, an optimization model has been developed that minimizes the consumption of the binder and establishes a relationship between the composition and properties of the mixture.
Generalization of the Riemann method for the trunk gas pipelines considering the quadratic law of resistance
Authors: Khujayev Ismatulla , Akhmadjonov Sarvarbek , Ismailov Аlisher
Published: June 2021

A mathematical model of the problem of pulse propagation in a semi-infinite gas pipeline was developed by expressing the pressure drop by the quadratic law of resistance and the local component of the gas inertia force by the law of conservation of momentum, using the law of conservation of mass in a one-dimensional statement. The model repeats the Riemann problem but takes into account the frictional resistance force. Using an auxiliary function in the form of the natural logarithm of the reduced density, and gauge functions, and certain simplifications, an equation for the reference solution of the problem in terms of gas velocity was derived and solved. For the analytical solution of the problem on gas velocity, the Riemann solution was used, and a refined analytical solution was obtained considering the quadratic law of resistance for the calculation of the perturbed and non-perturbed subdomains.
Effects of aviation kerosene contents on the environment and method of its cleansing
Authors: Isokov Yusuf , Yodgorov Normaxmat , Sultonov Sadulla , Khalilov Sanjar
Published: June 2021

The high content of sulfur compounds in aviation kerosene produced at the Bukhara Oil Refinery (BOR) is causing great damage to the environment. Purification of sulfur compounds in aviation kerosene using activated charcoal is effective. One way to remove sulfur compounds from aviation kerosene is to clean them using activated charcoal (adsorbent) obtained based on fruit pods.

Purification of aviation kerosene from mercaptans is a chemical adsorption process, using activated charcoal obtained based on shells of fruit seeds (walnuts, peaches, apricots, etc.). The adsorption of activated carbon obtained on the basis of husks of fruit seeds (walnuts, peaches, apricots, etc.) depends on the physicochemical properties; such activated charcoals were obtained by thermochemical methods.
Transformations of the herpetofauna of South-Western Kyzylkum (Uzbekistan) under the influence of technogenesis
Authors: Shernazarov Elmurad , Jumayev Fazliddin
Published: June 2021

The diversity of herpetofauna in the natural ecosystem of the southwestern part of Kyzylkum has been studied quite deeply. In recent decades, vast desert areas have been developed for agricultural crops, and a network of irrigation facilities has been set up for watering and water supply development of new lands and socio-cultural objects. However, the study of the animal world, including the complex of amphibians and reptiles under the influence of anthropogenic factors, has been overlooked in the transformed areas. In this paper, we present the impact and consequences of man-made factors on herpetofauna of the developed areas of the Bukhara region, using the example of hydraulic structures – collectors. The studies were carried out along the Northern collector at the Ramitan and Shafirkan stationary points. Seasonal field works were carried out from March to May and in September 2018, in October-November 2019, and June-August 2020. The population density of the species was determined based on permanent and selective routes. In total, about 80 day-time and nighttime observations were carried out, with a length of more than 130 km. The fauna of the studied area is represented by two species of amphibians and 17 species of reptiles, including three species which are listed in the Red Book of Uzbekistan and Annex I and II of CITES of which one is the IUCN Red List. According to the seasons of the year, the current state of the species population, their habitats, the dynamics of population, and the ratio of adults to young individuals are described. The expansion of the territorial space of two species of amphibians and two species of reptiles in connection with the construction of the collector-drainage network system was established. Detailed data on the negative impact of irrigation agriculture on desert species that are on the verge of complete extinction in the developed areas are provided. It is advisable to conduct conservation activities on critically endangered species regularly.
Issues of rational distribution of water resources under deficit conditions
Authors: Yakubov Maksadhon , Gafurov Yusufbek , Varlamova Lyudmila
Published: June 2021

Water is one expensive resource that can run out. The article discusses the issues of determining property rights, which is one of the necessary conditions for the effective functioning of the market mechanism. In Uzbekistan, the source of clean water is groundwater, which is less prone to pollution than surface water. The paper considers two systems of water consumption rights: riparian and appropriative. The features of these systems are presented. In addition, the uneven distribution of water resources across regions requires large investments in transportation through the construction of branch canals and the laying of extended water supply networks. It should be noted that the benefits of the constructed canals will vary significantly for water users depending on their location. Due to water losses when passing through the diversion canal, agents located at the beginning of the diversion canal find themselves in an advantageous position compared to other water users. At the same time, investments in the maintenance of the water distribution system, made at the beginning of the branch canal, bring benefits to all water users located downstream. One of the most well-known approaches to constructing an indicator of water scarcity is the Falkenmark water stress index.
Physicomathematical models of seeds and errors in calculating the volume of an electro terminator filled with seeds
Authors: Denmukhammadiev Aktam , Pardaev Abror , Begmatov Murod , Abdirakhmonov I , Akhmedov Ma'murjon
Published: June 2021

The article provides data on the impact of high-voltage current of electric spark discharges on the culture of gummosis located on the surface of cotton seed, and the article presents data on the impact of high-voltage electric spark discharges on the gummose culture located on the surface of the cotton seed. In this case, cotton seeds were taken as the basis for the physical model, consisting of three component parts, respectively, having a chalazal part, a lateral part, and a micropile. In the initial period of seed treatment, moisture penetrates the inside of the seed from the outside. Studied three-dimensional volumetric figures (hemisphere, cylinder, cone, etc.), carried out a literature review and mathematical calculations determined the calculation errors. The vessels of various shapes were compared. The prerequisites for determining the calculation errors have been made.
Experimental justification of the stability of the floating unit
Authors: Zimnyukov Vladimir , Zborovskaya Marina , Fartukov Vasiliy , Zaitsev Anton
Published: June 2021

One of the main tasks arising when installing a floating hydroelectric power unit on a foundation without preliminary excavation is a thorough justification of the shear stability and bearing capacity of the "floating hydroelectric power unit - foundation" system on a complex geological massif. Failure to take into account these factors can lead to serious consequences during the landing of the structure in the target and further operation. It should be emphasized that this problem still includes a number of difficulties and does not always allow obtaining exact solutions in a volumetric setting. Based on the selection of a wide range of model materials, bases of various capacities were modelled for four models. In this case, the shear real characteristics of alluvial soils and their change after reinforcing cementation were taken into account. The studies were carried out on 4 models under static loads with bringing them to destruction. The models reproduced the real geological conditions at the base of the block, simulated deformation, and shear characteristics. Indicator diagrams of displacements, damage patterns, and generalized safety factors for bearing capacity were obtained. Model tests have shown that reinforcing cementation reduces not only the values of horizontal and vertical displacements of structures but also leads to a significant increase in the safety factor.
Biological treatment of industrial and domestic wastewater of a brewery in Uzbekistan
Authors: Egamberdiev N.B. , Sharipjonova Zilola , Nasibov Bobur , Khomidov A.O. , Alimova M.I. , Abdumalikov A.A.
Published: June 2021

During the period of water shortage in the Republic, modern resource-saving irrigation methods and the use of purified and industrial waters and their reuse in irrigation is an urgent problem in ecology. Among the methods for treating industrial wastewater in a cheaper, cost effective way is the biological treatment method. It is the study of the effectiveness of biological treatment of industrial wastewater from primary winemaking using selected strains of aquatic plants (pistia).

The object of wastewater research is selecting a Pistia algae strain, carrying out biochemical, hydrochemical analyses of wastewater before and after treatment, and the chemical composition of the Pistia algae biomass. All studies were carried out according to the standard studies of UzGOST for waste and drinking water and algological methods used by the Institute of Botany of ANRUz, State Enterprise "Institute GIDROINGEO", etc.

The efficiency of biological purification of wastewaters of primary winemaking by higher aquatic plants of the pistia was established. With the help of the research carried out, the wastewater treatment of the food plant, in particular, the Kibray wine station with the Pistia algae, was established:

the optimal parameters of growth, development and purification capacity of pistia algae were established for various variants of experiments and wastewater samples;

designed and assembled a semi-industrial plant for biological wastewater treatment of the Kibray wine station and carried out work on industrial wastewater treatment.

Wastewater from the Kibray wine station contains organic compounds, namely yeast sediments, proteins, fats, carbohydrates, fiber, which are food for Pistia algae. Pistia biomass obtained after cultivation in wastewater after sterilization can be used as feed in livestock and poultry farming, as it contains a large number of proteins, fats and carbohydrates.
Influencing of land transport load on structure of backfill arched Road Bridge
Authors: Miralimov Mirzakhid , Ishankhodjaev Abdurakhman , Almenov Khudaybergan , Muminov Eldior
Published: June 2021

In this paper, for the objective assessment of stress-strain state parameters of backfill arched road bridge, the research work is carried out, where the model of reinforced concrete, corrugated structure is exposed to modern land transport load.

In the course of numerical studies, stresses and deformations in sections of structure and the soil are determined. These studies allow revealing the mechanism of operation of corrugated reinforced concrete structures in the body of an embankment of highways when passing modern transport loads along with them.
Influence of complex chemical additives on the rheological properties of cement paste and concrete mixture
Authors: Turgunbaev Urinbek , Toxirov Bobur
Published: June 2021

The article studies the effect of complex chemical additives on the water demand of cement, the setting time of the cement paste, the consumption of cement and additives KJ-3 on the viscosity of the concrete mixture, and also determines the normal density of the cement paste without the additive and with the plasticizing additive and the rheological characteristics of the concrete mixture with the additive KJ- 3.
Experimental and theoretical assessment of the long-term strength of lightweight concrete and its components under compression and tension, taking into account the macrostructure of the material
Authors: Raupov Choriqul , Karimova Anora , Zokirov Fakhriddin , Khakimova Yoqutxon
Published: June 2021

Experimental studies of concrete static fatigue require quite laborious and time-consuming tests. Insufficient data on static fatigue for concrete and the absence of an adequate theoretical base until recently did not allow using a generalized approach to estimate static fatigue parameters for different types of concrete. The paper presents the results of extensive experimental studies on static fatigue strength under tension and compression for lightweight concrete, mortar matrix, and hardened cement paste. A theoretical equation based on the fracture mechanics approach has been proposed and discussed for approximating experimental results and predicting static fatigue strength, which can be used for normalization of this parameter. The proposed equation displays better estimates compared to this used in the energy approach and empirical formulas.
Important risk factors for road accidents
Authors: Imamaliev Dilshod , Urakov Aslidin , Darabov Muzrob , Sayfutdinova Ruzigul
Published: June 2021

This article analyzes the relationship and influence of factors such as the population, the level of motorization, economic development, and the state of the state road network on the state of the risk of road accidents, including the level of mortality and road injuries, as well as the relevance of improving methods for assessing, managing and predicting the risk of accidents in road traffic. National indicators of the level of road deaths and injuries in different countries were studied. The relationship between road accidents and the level of motorization, income of the population, the state of the road network, and other indicators were revealed. The urgency of the problem of road accidents and the organization of measures to reduce the level of road accidents is emphasized. It also takes into account the special importance of forming conceptually new approaches to the task of improving the efficiency of public administration in the field of organization and maintenance of road traffic through the implementation of the Concept of Road Safety in the Republic of Uzbekistan for the period 2018-2022, which includes the following main directions: further improvement of the regulatory framework in the field of road safety, including significant strengthening of responsibility for gross violations of traffic rules; comprehensive improvement of road infrastructure, improving the quality of roads, creating reliable conditions for the safe movement of vehicles; improving the legal culture, the necessary knowledge, and skills of road users, strengthening their discipline.
Influence of climatic conditions on the occurrence of wheel track deformation on asphalt paved roads
Authors: Saidakberova Iroda , Yadgarov Sirojiddin , Qurbonov Bobomurod , Pulatova Zulfiya
Published: June 2021

When the car moves, a vertical, longitudinal and transverse dynamic force is generated, where there is a link between the road cover and the wheel. Repeated loads from vehicles and the impact of climatic factors lead to deformation in the pavement and pavement of the road. In deformation and deformation, the geometric dimensions and durability of the road pavement are lost. Disturbances-loss of dimensions and loss of durability of parts of the construction is understood. In practice, all types of deformation and distortion are often regarded as a drawback of road conditions [1].
Filter leaching of salt soils of automobile roads
Authors: Hudaykulov Rashidbek , Makhmudova Dilfuza , Kayumov Dilshod , Zafarov Olmos
Published: June 2021

Globally, in arid regions, due to the irrational use of water resources for irrigating plants, salinization of soils occurs, which causes significant damage to the country's economy. In particular, recently in some regions of Uzbekistan, there has been a rise in groundwater and flooding of territories. In these areas, where the soil bases of highways contain such readily soluble salts as: NaCL, Na2SO4·10H2O, MgSO4·7H2O, MgCL2·6H2O, CaCL2·6H2O, NaHCO3, Na2CO3·10H2O, CaCO3 and CaSO4·2H2O, additional suffusion precipitation is often observed which lead to deformations of road surfaces. Additional precipitation is due to the dissolution of salt crystals upon ingress of moisture during filtration leaching. Filtration leaching of soils was carried out in the F-1M device according to the upward flow pattern. To determine the amount of leached salts during the experiment, the infiltrate was taken, its volume and mineralization were recorded. At the end of the tests, the soil was tested according to the general scheme. To assess the influence of the leaching process on the strength indices of the studied soils by the methods of consolidated and fast shear, tests of pre-leached samples were performed. When testing soils, samples were cut, pre-compacted with the same specified load, and leached for a month. In laboratory conditions, the deformation modulus was determined by performing compression experiments. In connection with a sharp change in the modulus of deformation of soils during moistening, the tests were carried out at two values of humidity: at natural and after water saturation without the possibility of swelling. The study results show that the deformation modulus of water-saturated loams satisfactorily correlates with the value of the initial porosity coefficient and decreases as a result of water saturation and leaching. The degree of decrease depends on the value of the initial deformation modulus: the higher it is, the more significant its change. The value of the coefficient of weakening of the soil structure depends on the effective average pressure. The criterion for the permissible salt content in the base of the roadbed of highways should be taken not only the value of the degree of salinity but also the change in the indicators of the mechanical properties of soils used in the design of the construction of the roadway during soaking and leaching.
Enhancement of methodology for protection of structures in contradiction of thermal effects
Authors: Rojkova Еlena , Ruzieva Nodira , Ergashev Zuxritdin
Published: June 2021

The research paper is devoted to protection of structures against heat and temperature effects. The necessity of improving the calculation of multilayered fence structures is shown. The solution of a one-dimensional unsteady heat conduction equation with constant and variable coefficients allowing to use of inhomogeneous and anisotropic materials as the fence material is given. An example of the solution of a fence made of inhomogeneous and anisotropic material is given. Solution of heat conduction equation is obtained by the recurrence-operator method. The solution of one-dimensional unsteady heat conduction equation with variable coefficients is obtained using the recurrence-operator method. The possibility of using the solution of the equation for multilayered inhomogeneous anisotropic fence materials is indicated.
The lower limit of the first frequency of natural vibrations externally statically indeterminate truss: analytical solution
Authors: Kirsanov Mikhail , Shirokov Alexander
Published: June 2021

A scheme of a statically determinate planar truss with two additional supports duplicating the main ones is proposed. The formula for the dependence of the lower estimate of the first natural frequency on the number of panels is obtained. The solution is compared with the numerical one. Determination of the forces in the rods by the method of cutting out the nodes and with all the transformations performed in the Maple computer mathematics system. The high accuracy of the result is shown with a large number of panels.