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    Tytuł:
    The feasibility of using high-resolution ultrasonography to assess ulnar nerve in patients with diabetes mellitus
    Przydatność ultrasonografii wysokiej rozdzielczości w badaniu nerwu łokciowego u pacjentów chorujących na cukrzycę
    Autorzy:
    Chen, Jun
    Wang, Chun-Lei
    Wu, Shan
    He, Shan
    Ren, Jun
    Powiązania:
    https://bibliotekanauki.pl/articles/1033382.pdf
    Data publikacji:
    2017
    Wydawca:
    Medical Communications
    Tematy:
    high-resolution ultrasonography
    Opis:
    Objective: The aim of this study was to investigate the usefulness of high-resolution ultrasonography for the diagnosis of polyneuropathy in diabetes mellitus patients by the examination of the ulnar nerves. Method: We recruited 100 healthy age-matched volunteers (50 women and 50 men) with 200 arms without diabetes or cubital tunnel syndrome as the control group. We assessed the upper limbs of 100 diabetes mellitus patients (45 women and 55 men), 40 of whom had electrophysiologically confirmed diabetic peripheral neuropathy and 60 had no diabetic peripheral neuropathy in the upper limbs. Age, sex, height and weight were recorded and the cross-sectional area of the ulnar nerve was measured at every predetermined site. Results: The cross-sectional area of the ulnar nerve was measured at six sites (mid-humerus, inlet of the cubital tunnel, outlet of the cubital tunnel, upon the medial epicondyle, 6 cm upon the wrist crease and Guyon tunnel). The ulnar nerve in two measuring sites (mid-humerus, upon the medial epicondyle) in the control group showed a statistical difference between men and women (p < 0.05). There was no statistical difference in the cross-sectional area in the control group when dominant and non-dominant arms were compared. The cross-sectional area was larger in the diabetic peripheral neuropathy group in three sites (inlet of the cubital tunnel, outlet of the cubital tunnel, Guyon tunnel) compared with those in the control group. Conclusion: High-resolution ultrasonography may be helpful in the early diagnosis of peripheral neuropathy in diabetic patients.
    Cel: Celem badania było określenie przydatności ultrasonografii wysokiej rozdzielczości w diagnostyce polineuropatii u pacjentów z cukrzycą poprzez badanie nerwu łokciowego. Metoda: Przebadano kończyny górne 100 pacjentów z cukrzycą (45 kobiet i 55 mężczyzn), z których 40 cierpiało na elektrofizjologicznie potwierdzoną obwodową neuropatię cukrzycową, a u 60 nie rozpoznano obwodowej neuropatii cukrzycowej w kończynach górnych. Jako grupa kontrolna w badaniu udział wzięło 100 zdrowych wolontariuszy w podobnym wieku (50 kobiet i 50 mężczyzn), niecierpiących na cukrzycę ani zespół kanału łokciowego (łącznie 200 rąk). Określono wiek, płeć, wzrost i wagę oraz zmierzono pole przekroju poprzecznego nerwu łokciowego w każdym ustalonym miejscu. Wyniki: Pole przekroju poprzecznego nerwu łokciowego zmierzono w sześciu miejscach (środek kości ramiennej, wejście do kanału łokciowego, wyjście z kanału łokciowego, nad nadkłykciem przyśrodkowym, 6 cm ponad nadgarstkiem i kanał Guyona). W grupie kontrolnej wykazano statystycznie istotną różnicę w nerwie łokciowym w dwóch miejscach pomiaru (środek kości ramiennej, nad nadkłykciem przyśrodkowym) pomiędzy mężczyznami a kobietami (p < 0,05). Nie wykazano różnicy statystycznej w polu przekroju poprzecznego w grupie kontrolnej podczas porównywania ręki dominującej i niedominującej. Pole przekroju poprzecznego było większe w grupie z obwodową neuropatią cukrzycową w trzech miejscach (wejście do kanału łokciowego, wyjście z kanału łokciowego, kanał Guyona) w porównaniu z grupą kontrolną. Wniosek: Ultrasonografia wysokiej rozdzielczości może okazać się pomocna we wczesnej diagnostyce neuropatii obwodowej u pacjentów z cukrzycą. Artykuł w wersji polskojęzycznej jest dostępny na stronie http://jultrason.pl/index.php/wydawnictwa/volume-17-no-70
    Źródło:
    Journal of Ultrasonography; 2017, 17, 70; 160-166
    2451-070X
    Pojawia się w:
    Journal of Ultrasonography
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The role of probiotic intervention in regulating gut microbiota, short-chain fatty acids and depression-like behavior in lead-exposed rats
    Autorzy:
    Chen, Xiaojun
    Meng, Shujuan
    Yu, Yongli
    Li, Shuang
    Wu, Lei
    Zhang, Yanshu
    Powiązania:
    https://bibliotekanauki.pl/articles/2085714.pdf
    Data publikacji:
    2022-02-15
    Wydawca:
    Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
    Tematy:
    depression
    lead exposure
    probiotic
    gut microbiota
    SCFAs
    neurobehavioral tests
    Opis:
    ObjectivesThe aim of this study was to observe the depression-like behavior changes of rats exposed to lead with or without probiotic intervention, and to investigate changes in the gut microbiota and fecal short-chain fatty acids (SCFAs) levels after lead exposure, and the possible functions of probiotics in this process.Material and MethodsAdult male Sprague Dawley rats were exposed to a 300 mg/l lead acetate solution for 24 weeks, with or without probiotic (freeze-dried powder containing Lactobacillus and Bifidobacterium: 6 billion live bacteria/2 g) intervention in weeks 17–24. The sucrose preference test (SPT), the forced swim test (FST), and the tail suspension test (TST) were preformed to study the depression-like behaviors of these rats. The alteration of rat gut microbiota induced by lead exposure was analyzed by 16S rRNA sequencing, and the levels of fecal SCFAs were detected using gas chromatography.ResultsNeurobehavioral tests showed that lead exposure induced depression-like behavior in rats, including reduced sucrose preference in the SPT, and increased immobility times in the FST and the TST. Sequencing and gas chromatography showed that lead exposure changed the structure and the phylogenetic diversity of the gut microbiota, as well as significantly altered the levels of SCFAs. Moreover, the depression-like behaviors, and the changes in both gut microbiota and SCFAs, could be mitigated by probiotic intervention.ConclusionsLead exposure not only changes the structure and diversity of the gut microbiome but also affects metabolic function. Probiotic intervention may be a novel initiative for the prevention and treatment of neurological damage following lead exposure. Health. 2022;35(1):95–106
    Źródło:
    International Journal of Occupational Medicine and Environmental Health; 2022, 35, 1; 95-106
    1232-1087
    1896-494X
    Pojawia się w:
    International Journal of Occupational Medicine and Environmental Health
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Photovoltaic power prediction based on improved grey wolf algorithm optimized back propagation
    Autorzy:
    He, Ping
    Dong, Jie
    Wu, Xiaopeng
    Yun, Lei
    Yang, Hua
    Powiązania:
    https://bibliotekanauki.pl/articles/27309934.pdf
    Data publikacji:
    2023
    Wydawca:
    Polska Akademia Nauk. Czasopisma i Monografie PAN
    Tematy:
    BP neural network
    photovoltaic power generation
    PSO–GWO model
    PSO–GWO–BP prediction model
    particle swarm optimization
    gray wolf optimization
    back propagation
    standard grey wolf algorithm
    Opis:
    At present, the back-propagation (BP) network algorithm widely used in the short-term output prediction of photovoltaic power stations has the disadvantage of ignoring meteorological factors and weather conditions in the input. The existing traditional BP prediction model lacks a variety of numerical optimization algorithms, such that the prediction error is large. The back-propagation (BP) neural network is easy to fall into local optimization thus reducing the prediction accuracy in photovoltaic power prediction. In order to solve this problem, an improved grey wolf optimization (GWO) algorithm is proposed to optimize the photovoltaic power prediction model of the BP neural network. So, an improved grey wolf optimization algorithm optimized BP neural network for a photovoltaic (PV) power prediction model is proposed. Dynamic weight strategy, tent mapping and particle swarm optimization (PSO) are introduced in the standard grey wolf optimization (GWO) to construct the PSO–GWO model. The relative error of the PSO–GWO–BP model predicted data is less than that of the BP model predicted data. The average relative error of PSO–GWO–BP and GWO–BP models is smaller, the average relative error of PSO–GWO–BP model is the smallest, and the prediction stability of the PSO–GWO–BP model is the best. The model stability and prediction accuracy of PSO–GWO–BP are better than those of GWO–BP and BP.
    Źródło:
    Archives of Electrical Engineering; 2023, 72, 3; 613--628
    1427-4221
    2300-2506
    Pojawia się w:
    Archives of Electrical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    List Edge Coloring of Planar Graphs without 6-Cycles with Two Chords
    Autorzy:
    Hu, Linna
    Sun, Lei
    Wu, Jian-Liang
    Powiązania:
    https://bibliotekanauki.pl/articles/32083824.pdf
    Data publikacji:
    2021-02-01
    Wydawca:
    Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
    Tematy:
    planar graph
    edge choosable
    list edge chromatic number
    chord
    Opis:
    A graph G is edge-L-colorable if for a given edge assignment L = {L(e) : e ∈ E(G)}, there exists a proper edge-coloring φ of G such that φ(e) ∈ L(e) for all e ∈ E(G). If G is edge-L-colorable for every edge assignment L such that |L(e)| ≥ k for all e ∈ E(G), then G is said to be edge-k-choosable. In this paper, we prove that if G is a planar graph without 6-cycles with two chords, then G is edge-k-choosable, where k = max{7, Δ(G) + 1}, and is edge-t-choosable, where t = max{9, Δ(G)}.
    Źródło:
    Discussiones Mathematicae Graph Theory; 2021, 41, 1; 199-211
    2083-5892
    Pojawia się w:
    Discussiones Mathematicae Graph Theory
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical simulation and experimental study on formation of high concentration of H2 generated by gas explosion.
    Autorzy:
    Lei, B.
    Wu, B.
    Zhao, Y.
    Ashraf, M. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/259802.pdf
    Data publikacji:
    2016
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    gas explosion
    high concentration of H2
    numerical simulation
    explosion experiment
    Opis:
    In coal mine fire rescues, if the abnormal increase of gas concentration occurs, it is the primary thing to analyze the reasons and identify sources of the abnormal forming, which is also the basis of judge the combustion state of fire area and formulate proper fire reliefs. Nowadays, related researches have recognized the methane explosion as the source of high concentration of H2 formation, but there are few studies about the conditions and reaction mechanism of gas explosion generating high concentration of H2.Therefore, this paper uses the chemical kinetic calculation software, ChemKin, and the 20L spherical explosion experimental device to simulate the generating process and formation conditions of H2 in gas explosion. The experimental results show that: the decomposition of water vapor is the main base element reaction (R84) which leads to the generation of H2.The free radical H is the key factor to influence the formation of H2 generated from gas explosion. With the gradual increase of gas explosion concentration, the explosive reaction becomes more incomplete, and then the generating quantity of H2 increases gradually. Experimental results of 20L spherical explosion are consistent with the change trend about simulation results, which verifies the accuracy of simulation analysis. The results of explosion experiments show that when gas concentration is higher than 9%, the incomplete reaction of methane explosion increases which leads to the gradual increase of H2 formation
    Źródło:
    Polish Maritime Research; 2016, S 1; 131-137
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    SCREENING THE SPECIFIC SUBSTRATES OF ADENYLATION DOMAIN FROM MARINE ACTINOMYCETES BY FLUORESCENCE QUENCHING AND ISOTHERMAL TITRATION CALORIMETRY
    Autorzy:
    LEI, MING
    ZHAO, ZHIJUAN
    LIU, KE
    LIU, YANLI
    ZHANG, HUI
    WU, XUE
    GONG, SIYING
    MA, YANLING
    ZHAO, HAOBIN
    LIU, JINLIN
    MIN, JINRONG
    QI, CHAO
    Powiązania:
    https://bibliotekanauki.pl/articles/895432.pdf
    Data publikacji:
    2018-12-31
    Wydawca:
    Polskie Towarzystwo Farmaceutyczne
    Tematy:
    A domain
    Aspartic acid
    Fluorescence quenching (FQ)
    Isothermal titration calorimetry (ITC)
    Marine actinomycetes
    static quenching
    Opis:
    Adenylation domain (A domain) is a model of non-ribosomal peptide synthetases (NRPs), responsible for binding and activating the substrates-amino acids. In this study, a pGEX-2T-sare0718 recombinant plasmid (the gene sare0718 was cloned from Salinispora arenicola CNS-205, S.arenicola CNS-205) was transformed and expressed as a protein GST-Sare0718. Fluorescence quenching (FQ) was conducted to investigate the binding of 20 common amino acids to GST-Sare0718, then isothermal titration calorimetry (ITC) also be used[changed]. The results of FQ revealed that intrinsic fluorescence of GST-Sare0718 is quenched steadily by addition of aspartic acid (Asp) and glutamine (Gln) through static quenching mechanism. The binding constants Ka are Asp (1.504×106 L/mol) ≥ Gln (1.468×105 L/mol). And there is one binding site on the protein GST-Sare0718. We confirmed Asp preference of GST-Sare0718 by ITC. Therefore, Asp is the specific substrate. In addition, the experimental data indicates that the prediction system, “the specificity-conferring code”, is not suitable for marine actinomycetes. So it is urgent to set up a special predictive system for marine actinomycetes.
    Źródło:
    Acta Poloniae Pharmaceutica - Drug Research; 2018, 75, 6; 1287-1292
    0001-6837
    2353-5288
    Pojawia się w:
    Acta Poloniae Pharmaceutica - Drug Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Shrink-Proof Treatment Parameter Optimisation of Cashmere Yarn
    Autorzy:
    Li, Long
    Wang, Wei
    Zhang, Xian
    Wu, Lei
    Yang, Dan
    Powiązania:
    https://bibliotekanauki.pl/articles/2171991.pdf
    Data publikacji:
    2022
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
    Tematy:
    cashmere yarn
    shrink-proof
    potassium permanganate treatment
    yarn shrinkage percentage
    Opis:
    Cashmere fiber has soft hand and good elasticity. However, it exhibits shrink because of its scale. In this work, cashmere yarn (38.26 tex) was treated using NaCl-KMnO4 to reduce the shrink of cashmere yarn. Orthogonal design and fuzzy comprehensive evaluation were used for optimizing treating parameters. Experimental results showed that the yarn shrink percentage of treated yarn was 0.56% which was less than that untreated yarn, and the treated yarn strength had a little drop compared with untreated yarn. The fiber scale outline of treated yarn could be observed by SEM, but the scale edge is blunt and irregular.
    Źródło:
    Fibres & Textiles in Eastern Europe; 2022, 3 (151); 57--60
    1230-3666
    2300-7354
    Pojawia się w:
    Fibres & Textiles in Eastern Europe
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Antidiabetic cataract effects of GbE, rutin and quercetin are mediated by the inhibition of oxidative stress and polyol pathway
    Autorzy:
    Lu, Qian
    Hao, Meng
    Wu, Wenya
    Zhang, Nan
    Isaac, Adelusi
    Yin, Jiale
    Zhu, Xia
    Du, Lei
    Yin, Xiaoxing
    Powiązania:
    https://bibliotekanauki.pl/articles/1038521.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    Ginkgo biloba extract
    rutin
    quercetin
    diabetic cataract
    Opis:
    One of the earliest critical secondary complications of diabetes is the opacification of the eye lens - a condition strictly associated with diabetic cataract. The study presented here was designed to investigate the effect of Ginkgo biloba extract (GbE), rutin and quercetin on streptozotocin (STZ) induced diabetic cataract (DC) rats. Ten weeks after administration of GbE, rutin and quercetin, the opacity of diabetic rats' lenses was graded under a slit lamp. Then, the levels of malondialdehyde (MDA), reduced glutathione (GSH), advanced glycosylation end products (AGEs), and the activities of aldose reductase (AR) were estimated. The DC-induced rats produced less GSH, higher levels of MDA and AGEs as well as elevated AR activity when compared to the normal group. Administration of GbE, rutin and quercetin remarkably inhibited the AR activity, stimulated the production of glutathione, and decreased the levels of MDA and AGEs in the lenses of DC-induced rats, which eventually delayed the progression of lens opacification in diabetic rats to various degrees. Our results revealed that quercetin had the highest significant (P<0.05) potential to delay the progression of STZ-induced diabetic cataract when compared with rutin and GbE. The mechanism dictating this interesting prowess of quercetin might be attributed to its AR inhibitory strength, anti-lipid peroxidation potential and anti-AGEs activity.
    Źródło:
    Acta Biochimica Polonica; 2018, 65, 1; 35-41
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Variation of strata pressure and axial bolt load at a coal mine face under the effect of a fault
    Zmienność ciśnienia górotworu i obciążenia osiowe działające na segmenty obudowy w rejonie przodka spowodowane obecnością uskoków
    Autorzy:
    Shi, Hao
    Zhang, Houquan
    Song, Lei
    Wu, Yu
    Powiązania:
    https://bibliotekanauki.pl/articles/218749.pdf
    Data publikacji:
    2019
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    symulacje numeryczne FLAC 3D
    naprężenia osiowe działające na obudowę
    zachowanie górotworu
    górnictwo
    efekt uskoku
    model odprężania
    FLAC3D numerical simulation
    axial bolt load
    strata behavior
    mining and fault effect
    strain-softening model
    Opis:
    The cohesion and internal friction angle were characterized as quadratic functions of strain and were assumed to follow the Mohr-Coulomb criterion after the yield of peak strength. These mechanical parameters and their variations in post-peak softening stage can be exactly ascertained through the si-multaneous solution based on the data points of stress-strain curves of triaxial compression tests. Taking the influence of the fault into account, the variation of strata pressure and roadway convergence with coal advancement, the temporal and spatial distribution of axial bolt load were numerically simulated by FLAC3D (Fast Lagrangian Analysis of Continua) using the ascertained post-peak mechanical parameters according to the cohesion weakening and friction strengthening model. The change mechanism of axial load of single rock bolt as abutment pressure changes was analyzed, through the comparison analysis with the results of axial bolt load by field measurements at a coal mine face. The research results show that the simulated results such as the period of main roof weighting, temporal and spatial distribution of axial bolt load are in accordance with field measurement results, so the validity of the numerical model is testified. In front of the working face, the front abutment pressure increases first and then decreases, finally tends to be stable. A corresponding correlation exists between the variation of axial bolt load and rock deformation along the bolt body. When encountered by a fault, the maximum abutment pressure, the influential range of mining disturbance and the roadway convergence between roof and floor before the working face are all increased. In the roadways along the gob, axial bolt loads on the side of the working face decrease, while the other side one increases after the collapse of the roof. As superficial surrounding rock mass is damaged, the anchoring force of rock bolts will transfer to inner rock mass for balancing the tensile load of the bolts.
    Zwięzłość skał oraz kąt tarcia wewnętrznego zdefiniowano jako kwadratowe funkcje naprężenia, następnie przyjęto że ich rozkład po osiągnięciu naprężenia granicznego opisany jest wzorem Mohra-Coulomba. Wymienione parametry mechaniczne i ich zmienność po osiągnięciu naprężenia granicznego obliczyć można dokładnie poprzez jednoczesne rozwiązanie oparte o analizę punktów na krzywej wykresu rozciągania uzyskanych w testach ściskania trójosiowego. Uwzględniając wpływ obecności uskoku, zmienność ciśnienia w górotworze i konwergencji chodnika wraz z postępem przodka, rozkłady naprę-żeń i obciążeń działających na segmenty obudowy i ich zmienność w czasie i przestrzeni modelowano w oparciu o pakiet FLAC3D (Fast Lagrangian Analysis of Continua), wykorzystując uprzednio obliczone wielkości parametrów mechanicznych dla stanu po osiągnięciu naprężenia granicznego, zgodnie z mo-delem słabnącej zwięzłości i wzmocnionego tarcia. Mechanizm zmiany naprężeń osiowych działających na pojedynczy segment obudowy analizowano w odniesieniu do ciśnienia warstw sąsiadujących, poprzez analizę porównawczą wyników pomiarów obciążeń segmentów obudowy w rejonie przodka. Wykazano, że wyniki symulacji: okresy obciążenia stropu, rozkłady naprężeń i obciążeń działających na elementy obudowy i ich zmienność w czasie i przestrzeni zgodne są z wynikami pomiarów w miejscu, w ten sposób potwierdzając wiarygodność modelu numerycznego. W rejonie przodka ciśnienie warstw sąsiadujących w górotworze najpierw rośnie, następnie maleje, a w końcu stabilizuje się. Istnieje odpowiednia korelacja pomiędzy zmiennością rozkładu naprężeń i obciążeń działających na elementy obudowy a odkształceniem warstw skalnym wzdłuż konstrukcji obudowy. W przypadku wystąpienia uskoku, występuje maksymalne ciśnienie warstw otaczających- poważny czynnik powodujący wszelkiego rodzaju zaburzenia a także nasilenie konwergencji chodnika pomiędzy stropem a podłożem w rejonie przed przodkiem. W chodnikach wzdłuż zrobów, obciążenia osiowe obudowy działające z jednej strony maleją, po drugiej zaś stronie rejonu przodkowego rosną po zawale stropu. Płytka warstwa otaczającego górotworu ulega zniszczeniu, siła podtrzymująca obudowę przeniesiona zostanie wewnątrz górotworu, tak by zrównoważyć naprężenia rozciągające działające na obudowę.
    Źródło:
    Archives of Mining Sciences; 2019, 64, 2; 351-374
    0860-7001
    Pojawia się w:
    Archives of Mining Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Analysis of the cracking mechanisms in pre-cracked sandstone under radial compression by moment tensor analysis of acoustic emissions
    Autorzy:
    Wang, Guozhu
    Luo, Xulin
    Song, Lei
    Wang, Yu
    Han, Mouwang
    Song, Zhaocun
    Wu, Linjun
    Wang, Zukun
    Powiązania:
    https://bibliotekanauki.pl/articles/2174031.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    emisja akustyczna
    mechanizm pękania
    tensor momentu
    piaskowiec wstępnie spękany
    kompresja promieniowa
    acoustic emission
    cracking mechanism
    moment tensor
    pre-cracked sandstone
    radial compression
    Opis:
    Rock masses, especially those with different pre-existing cracks, are prone to instability and failure under tensile loading, resulting in different degrees of engineering disasters. Therefore, to better understand the effect of pre-existing cracks with different dip angles on the tensile instability failure behaviour of rocks, the mechanism of crack initiation, propagation and coalescence in precracked sandstone under radial compression loading is investigated through numerical simulations. The temporal and spatial evolution of acoustic emission (AE) events is investigated by the moment tensor (MT), and the fracture mode of micro-cracks is determined. The results show that the pre-existing cracks weaken the specimens. The strength, crack initiation points and macro-failure modes of the specimens differ significantly depending on the dip angle of the pre-existing crack. For different dip angles of the pre-existing cracks, all the micro-cracks at the crack initiation point are tensile cracks, which are dominant during the whole loading process, and mixed cracks are mainly generated near the upper and lower loading ends after the peak stress. Of the total number of events, more than 75% are tensile cracks; approximately 15% are shear mode cracks; and the remainder consist of mixed mode cracks. The study reveals the instability and failure mechanism of pre-cracked rock, which is of great significance to ensure the long-term stability of rock mass engineering.
    Źródło:
    Archives of Civil Engineering; 2022, 68, 3; 447--468
    1230-2945
    Pojawia się w:
    Archives of Civil Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of surface texture parameters on friction characteristics under starved lubrication
    Autorzy:
    Wu, Shen
    Zhang, Pan
    Wei, Haijun
    Chen, Lei
    Powiązania:
    https://bibliotekanauki.pl/articles/259916.pdf
    Data publikacji:
    2020
    Wydawca:
    Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
    Tematy:
    marine diesel engine
    cylinder liner and piston ring
    friction reduction
    starved lubrication
    laser texturing
    Opis:
    A cylinder liner and piston ring running under starved lubrication near the top dead centre (TDC) and bottom dead centre (BDC) cause abnormal friction and wear during operation of a marine diesel engine. The method of laser texturing is proposed to improve the surface friction property under this condition. Spherical crown pits with different parameters were formed on the surface of samples by femtosecond laser processing. The BDC and TDC conditions of oil starvation were simulated in a reciprocating friction and wear experiment, and a numerical model of Surface texture lubrication based on the Reynolds equation was established. The influence of the distribution density, diameter, and depth parameters of the texture on the surface properties was studied. In the BDC condition, compared with the untextured surface, the average coefficient of friction (COF) can be reduced by up to 24% and the average friction force can be reduced by up to 18%. In the TDC condition, the COF can be reduced by up to 19%, and the average friction force can be reduced by up to 18%. Therefore, the textures with various parameters should be arranged in different positions on the cylinder liner; more attention should be paid to the optimisation of diameter in the texture of the cylinder liner near the BDC, whereas more attention should be paid to the optimisation of distribution density in the texture of the cylinder liner near the TDC
    Źródło:
    Polish Maritime Research; 2020, 2; 96-106
    1233-2585
    Pojawia się w:
    Polish Maritime Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Enhanced biosolubilization of mid-low grade phosphate rock by formation of microbial consortium biofilm from activated sludge
    Autorzy:
    Xiao, Chunqiao
    Wu, Xiaoyan
    Zhu, Lei
    Yu, Tong
    Xu, Zhenghe
    Chi, Ruan
    Powiązania:
    https://bibliotekanauki.pl/articles/110353.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    biosolubilization
    phosphate rock (PR)
    microbial consortium
    activated sludge
    biofilm
    Opis:
    Mid-low grade phosphate rock (PR) is a potential source of free phosphate to facilitate crop growth, but a cost effective and environmentally responsible extraction process is required. In this study, the capacity of a microbial consortium from activated sludge to solubilize PR in a laboratory-scale column reactor was investigated. The microbial consortium proved capable of efficiently releasing soluble phosphate in the reactor effluent over the 90-day trial. The microbial consortium grew well in the column system as evidenced by reduced chemical oxygen demand (COD) in the reaction solution. Biofilm formation was identified as critical for biosolubilization of the mid-low grade PR. Imaging of the biofilm by scanning electron microscopy (SEM) revealed a dense network of microbial cells embedded in extracellular polymeric substances (EPS). The biofilm contained both oxic and anoxic zones. The pH decreased significantly in both the biofilm and the reaction solution during operation, indicating healthy growth of the microbial consortium with corresponding acid generation and subsequent enhancement of phosphate solubilization.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 1; 217-224
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Exposure to particulate matter 2.5 leading to lung microbiome disorder and the alleviation effect of Auricularia auricular-judae polysaccharide
    Autorzy:
    Zhang, Yanshu
    He, Bin
    Wu, Lei
    Mi, Xiaoyi
    Zhang, Lijin
    Li, Shuang
    Wang, Jian
    Yu, Xiaoyu
    Powiązania:
    https://bibliotekanauki.pl/articles/2152971.pdf
    Data publikacji:
    2022
    Wydawca:
    Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
    Tematy:
    PM 2.5
    inflammatory damage
    lung injury
    BALF
    microbiome disorder
    AAP
    Opis:
    Objectives The aim of the paper is to explore the role of lung microbiome disorder in lung tissue injury induced by exposure to particulate matter with a maximum diameter of 2.5 μm (PM2.5) and the alleviation effect of auricularia auricular-judae polysaccharide (AAP). Material and Methods Sprague Dawley rats were given PM2.5 suspension at a dose of 20 mg/l twice a week for 8 weeks. Then, 100 mg/kg or 200 mg/kg of AAP was administered to the rats after PM2.5 exposure. The bronchoalveolar lavage fluid (BALF) and lung tissue samples were collected at the end of the experiment. The BALF was meant to detect changes in lung microbiome by 16S sequences and cluster analysis, with the application of the principal component analysis and the partial least squares discriminant analysis. The levels of interferon-γ (IFN-γ), and interleukin (IL)-4, IL-8, and IL-10 in lung tissue were detected by the enzyme-linked immunosorbent assay method. The pathological changes in lung tissue were observed by hematoxylin and eosin staining. Results After PM2.5 exposure, the alveolar septum was widened, and the structures of alveolar walls were destroyed. There was inflammatory cells infiltration in the alveolar space and the interstitial space. Alpha diversity in BALF showed that the Chao1, ACE, Simpson, and Shannon values were increased, and the lung microbiome analysis revealed that the relative abundance of Firmicutes and Clostridium increased, while the relative abundance of Bacteroidetes and Akkermansia decreased. The contents of IFN-γ and IL-8 in lung tissue increased while the content of IL-10 decreased. After the administration of AAP, the alveolar structure damage was alleviated, and the interstitial hemorrhage, edema, and inflammatory cells infiltration were reduced. The Chao1 and ACE values decreased, and the taxonomic abundance values of Akkermansia were much higher. Simultaneously, the contents of IFN-γ, IL-4, and IL-8 decreased, and the content of IL-10 increased. Conclusions It was found that PM2.5 resulted in lung microbiome disorder, which might lead to the inflammation of lung tissue. It was also revealed that AAP could alleviate the inflammatory damage of lung tissue induced by PM2.5.
    Źródło:
    International Journal of Occupational Medicine and Environmental Health; 2022, 35, 6; 651-664
    1232-1087
    1896-494X
    Pojawia się w:
    International Journal of Occupational Medicine and Environmental Health
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Simulation study on clogging of suspended particles in in-situ leaching of uranium at different concentrations and flow velocity
    Autorzy:
    Zhou, Chunze
    Wang, Hongqiang
    Wu, Tongpan
    Hu, Eming
    Lei, Zhiwu
    Wang, Qingliang
    Powiązania:
    https://bibliotekanauki.pl/articles/24085848.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    in-situ leaching of uraniom
    physical clogging
    suspended particles
    porous medium
    permeability coefficient
    Opis:
    Clogging problem has become one of the key problems restricting the mining efficiency of in-situ leaching of uranium, and the related research on the law and mechanism of physical clogging has not been reported. In order to identify and understand the complicated law and mechanism, experimental device is established to simulate the physical clogging caused by suspended particles in the uranium process, the physical clogging law and mechanism under different concentrations and velocity of flow are studied. The experimental results show that with the concentration of suspended particles increasing from 100, 200, 300 to 400 mg/L, the permeability of porous media gradually decreases, and the clogging phenomenon becomes more and more obvious. When the size of suspended particles is small and the velocity is 15 mL/min, the porous medium will not appear clogging, while the velocity is 25mL/min, the whole porous medium will slowly appear internal deposition clogging. When the size of suspended solids is larger and the flow rate is 9, 12, 15mL/min, the higher the velocity, the faster the clogging will be, and backwash can alleviate the surface clogging but cannot change the final clogging result. According to the experiment and actual situation, the physical clogging in in-situ leaching of uranium is mainly surface clogging and filter clogging.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2023, 59, 2; art. no. 162150
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of the toxicity of the ionic liquid 1-butyl-3-methylimidazolium chloride to Saccharomyces cerevisiae AY93161 for lignocellulosic ethanol production
    Autorzy:
    Zhu, Shengdong
    Yu, Pei
    Lei, Mingke
    Tong, Yanjie
    Zheng, Lu
    Zhang, Rui
    Ji, Jun
    Chen, Qiming
    Wu, Yuanxin
    Powiązania:
    https://bibliotekanauki.pl/articles/778529.pdf
    Data publikacji:
    2013
    Wydawca:
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
    Tematy:
    Ionic liquid
    [bmim]Cl
    toxicity
    Saccharomyces cerevisiae AY93161
    lignocellulosic ethanol production
    Opis:
    Ionic liquid (IL) pretreatment of lignocellulosic materials has provided a new technical tool to improve lignocellulosic ethanol production. To evaluate the influence of the residual IL in the fermentable sugars from enzymatic hydrolysis of IL pretreatment of lignocellulosic materials on the subsequent ethanol fermentation, the toxicity of the IL 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) to Saccharomyces cerevisiae AY93161 was investigated. Firstly, the morphological structure, budding and metabolic activity of Saccharomyces cerevisiae AY93161 at different [BMIM]Cl concentrations were observed under an optical microscope. The results show that its single cell morphology remained unchanged at all [BMIM]Cl concentrations, but its reproduction rate by budding and its metabolic activity decreased with the [BMIM]Cl concentration increasing. The half effective concentration (EC50) and the half inhibition concentration (IC50) of [BMIM]Cl to Saccharomyces cerevisiae AY93161 were then measured using solid and liquid suspension culture and their value were 0.53 and 0.39 g.L-1 respectively. Finally, the influence of [BMIM]Cl on ethanol production was investigated. The results indicate that the [BMIM]Cl inhibited the growth and ethanol production of Saccharomyces cerevisiae AY93161. This toxicity study provides useful basic data for further development in lignocellulosic ethanol production by using IL technology and it also enriches the IL toxicity data.
    Źródło:
    Polish Journal of Chemical Technology; 2013, 15, 2; 94-98
    1509-8117
    1899-4741
    Pojawia się w:
    Polish Journal of Chemical Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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