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1.
Materials (Basel) ; 17(3)2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38591540

RESUMO

The control of the solidification structure of a casting billet is directly correlated with the quality of steel. Variations in superheat can influence the transition from columnar crystals to equiaxed crystals during the solidification process, subsequently impacting the final solidification structure of the billet. In this study, a model of microstructure evolution during billet solidification was established by combining simulation and experiment, and the dendrite growth microstructure evolution during billet solidification under different superheat was studied. The results show that when the superheat is 60 K, the complete solidification time of the casting billet from the end of the 50 mm section is 252 s, when the superheat is 40 K, the complete solidification time of the casting billet is 250 s, and when the superheat is 20 K, the complete solidification time of the casting billet is 245 s. When the superheat is 20 K, the proportion of the equiaxed crystal region is higher-the highest value is 53.35%-and the average grain radius is 0.84556 mm. The proportion of the equiaxed crystal region decreases with the increase of superheat. When the superheat is 60 K, the proportion of the equiaxed crystal region is the lowest-the lowest value is 46.27%-and the average grain radius is 1.07653 mm. Proper reduction of superheat can obviously reduce the size of equiaxed crystal, expand the area of equiaxed crystal and improve the quality of casting billet.

2.
J Clin Nurs ; 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38500234

RESUMO

OBJECTIVES: To compare and analyse the differences in the clinical reasoning competence of nurses with different working years and their relationship with self-directed learning competence. METHODS: A cross-sectional survey design (online investigation) was used. A total of 376 nurses were recruited from four independent hospitals in China. Online questionnaires collected data on nurses' demographic characteristics and assessed their clinical reasoning and self-directed learning competence. Pearson correlation analysis, t-test, analysis of variance (ANOVA) and multivariate regression analysis were used. RESULTS: Clinical reasoning competence scores of nurses with working years >10 years were higher than those of other nurses. Self-directed learning competence scores of nurses with working years of <1 year and (from ≥1 year to <3 years) were lower than those of nurses with working years of 6-10 years and >10 years. Self-directed learning competence scores of nurses with working years of 3-5 years were lower than those of nurses with working years of >10 years. There was a positive correlation between clinical reasoning competence, self-directed learning competence and each dimension among nurses of different working years. There are differences in the influence of different dimensions of self-directed learning competence on clinical reasoning competence among different working years. CONCLUSION: There were differences in clinical reasoning and self-directed learning competence among nurses with different working years. Self-directed learning competence is a positive predictor of nurses' clinical reasoning competence, which applied to nurses with all working years; however, the specific effect of self-directed learning competence on clinical reasoning competence differed among nurses with different working years. IMPLICATION FOR NURSING MANAGERS: Nursing managers should pay attention to the development characteristics of clinical reasoning competence and self-directed learning competence of nurses with different working years and determine effective intervention strategies according to specific influencing factors.

3.
Plant Biotechnol J ; 2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38492213

RESUMO

Wood formation, which occurs mainly through secondary xylem development, is important not only for supplying raw material for the 'ligno-chemical' industry but also for driving the storage of carbon. However, the complex mechanisms underlying the promotion of xylem formation remain to be elucidated. Here, we found that overexpression of Auxin-Regulated Gene involved in Organ Size (ARGOS) in hybrid poplar 84 K (Populus alba × Populus tremula var. glandulosa) enlarged organ size. In particular, PagARGOS promoted secondary growth of stems with increased xylem formation. To gain further insight into how PagARGOS regulates xylem development, we further carried out yeast two-hybrid screening and identified that the auxin transporter WALLS ARE THIN1 (WAT1) interacts with PagARGOS. Overexpression of PagARGOS up-regulated WAT1, activating a downstream auxin response promoting cambial cell division and xylem differentiation for wood formation. Moreover, overexpressing PagARGOS caused not only higher wood yield but also lower lignin content compared with wild-type controls. PagARGOS is therefore a potential candidate gene for engineering fast-growing and low-lignin trees with improved biomass production.

4.
Materials (Basel) ; 17(5)2024 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-38473511

RESUMO

Strand electromagnetic stirring (S-EMS), a technique applied in the secondary cooling zone, enhances the solidification structure of casting slabs. This study examines how the arrangement pattern of electromagnetic stirring rollers-face-to-face, side-to-side or up-down misalignment produces this enhancement. It uses simulations to analyze the electromagnetic field distribution in these configurations. The findings demonstrate that: (1) The magnetic flux density distribution in the casting slab is related to the arrangement pattern of the electromagnetic stirring rollers. (2) The face-to-face arrangement produces the largest and most concentrated electromagnetic force compared to the other two arrangement patterns. (3) S-EMS can effectively improve the equiaxed grain ratio of casting slabs. Before and after EMS is turned on, casting slabs' average equiaxed grain ratio goes up from 8% to 33%.

5.
Pain Res Manag ; 2024: 9982411, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38312327

RESUMO

Background: Reaction time is a reliable indicator of the velocity and efficiency of neuromuscular control and may be associated with fear-avoidance beliefs. However, the effect of exercise-induced muscle fatigue on reaction time in chronic low back pain (cLBP) and its relationship with fear-avoidance beliefs remains poorly understood. Objectives: This study aimed to reveal the relationship between fear-avoidance beliefs and reaction time changes before and after exercise-induced muscle fatigue in cLBP. Methods: Twenty-five patients with cLBP were tested by the Biering-Sorensen test (BST) to induce exhaustive muscle fatigue. Total reaction time (TRT), premotor time (PMT), and electromechanical delay (EMD) of dominated deltoid muscle were recorded by surface electromyography during the arm-raising task with visual cues before and after muscle fatigue. The mean difference (MD) of TRT (MDTRT), PMT (MDPMT), and EMD (MDEMD) was calculated from the changes before and after muscle fatigue. Fear-avoidance beliefs questionnaire (FABQ) was applied to evaluate fear-avoidance beliefs before muscle fatigue. In addition, the duration time of BST was recorded for each subject. Results: TRT and PMT of dominated deltoid muscle were prolonged after exercise-induced muscle fatigue (Z = 3.511, p < 0.001; t = 3.431, p = 0.001), while there was no statistical difference in EMD (Z = 1.029, p = 0.304). Correlation analysis showed that both the MDTRT and MDPMT were positively correlated with FABQ (r = 0.418, p = 0.042; r = 0.422, p = 0.040). Conclusions: These findings suggested that we should pay attention to both muscle fatigue-induced reaction time delay in cLBP management and the possible psychological mechanism involved in it. Furthermore, this study implied that FABQ-based psychotherapy might serve as a potential approach for cLBP treatment by improving reaction time delay. This trial is registered with ChiCTR2300074348.


Assuntos
Dor Lombar , Humanos , Dor Lombar/terapia , Fadiga Muscular/fisiologia , Tempo de Reação , Eletromiografia , Medo/psicologia , Inquéritos e Questionários , Avaliação da Deficiência
6.
Plant Cell ; 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38315889

RESUMO

Roses are among the most popular ornamental plants cultivated worldwide for their great economic, symbolic, and cultural importance. Nevertheless, rapid petal senescence markedly reduces rose (Rosa hybrida) flower quality and value. Petal senescence is a developmental process tightly regulated by various phytohormones. Ethylene accelerates petal senescence, while gibberellic acid (GA) delays this process. However, the molecular mechanisms underlying the crosstalk between these phytohormones in the regulation of petal senescence remain largely unclear. Here, we identified SENESCENCE-ASSOCIATED F-BOX (RhSAF), an ethylene-induced F-box protein gene encoding a recognition subunit of the SCF-type E3 ligase. We demonstrated that RhSAF promotes degradation of the GA receptor GIBBERELLIN INSENSITIVE DWARF1 (RhGID1) to accelerate petal senescence. Silencing RhSAF expression delays petal senescence, while suppressing RhGID1 expression accelerates petal senescence. RhSAF physically interacts with RhGID1 s and targets them for ubiquitin/26S proteasome-mediated degradation. Accordingly, ethylene-induced RhGID1C degradation and RhDELLA3 accumulation are compromised in RhSAF-RNAi lines. Our results demonstrate that ethylene antagonizes GA activity through RhGID1 degradation mediated by the E3 ligase RhSAF. These findings enhance our understanding of the phytohormone crosstalk regulating petal senescence and provide insights for improving flower longevity.

7.
Artigo em Inglês | MEDLINE | ID: mdl-38330558

RESUMO

Objective: The incidence of stroke worldwide is increasing year by year. With the enhancement of public health awareness, people's demand for the quality of stroke rehabilitation is getting higher and higher, so better quality care measures are needed in the treatment of stroke. Based on this, this paper explores the impact of a new type of nursing care measure, the complementary health care model combined with condition tracking, on stroke patients. Methods: 238 stroke patients were randomly divided into a conventional group (n=119) and a combined group (n=119). 238 stroke patients were randomly divided into conventional group (n=119) and combined group (n=119). The conventional group received routine care, in which doctors and nursing carried out their own work without cooperation after the patients were admitted to the hospital; the combined group received a complementary health care model and condition tracking, in which doctors and nurses jointly checked the rooms, discussed cases, jointly formulated treatments and nursing care plans, and jointly formulated the patients' discharge and rehabilitation plans after the patients were admitted to the hospital. Before the intervention, at the time of discharge, and 6 months after discharge, the neurological function of the patients in both groups was assessed using the National Institutes of Health Stroke Scale (NIHSS) and the Fugl-Meyer (FMA) scale, the cognitive function of the patients in both groups was assessed using the Montreal Cognitive Assessment (MoCA) scale and the Measured Mental State Examination (MMSE), and the cognitive function of the patients in both groups was assessed using the General Self-Efficacy Scale (GSS) and the Montreal Cognitive Assessment (MCA) scale. General Self-Efficacy Scale (GSES) to assess self-efficacy, Exercise Adherence Questionnaire (EAQ) to assess adherence to functional exercise and Specific Quality of Life Scale (SSQoL-12) to assess the quality of life of patients in both groups, and the self-developed satisfaction with nursing care to assess patients' satisfaction with the care model. Results: Before the intervention, there was no difference in the National Institutes of Health Stroke Scale (NIHSS), the Fugl-Meyer Assessment (FMA), the Montreal Cognitive Assessment (MoCA), the Mental State Examination (MMSE), the General Self-Efficacy Scale (GSES), the Exercise Adherence Questionnaire (EAQ) and the Stroke-Specific Quality of Life Scale-12 (SSQoL-12) scores between the two groups (P > .05). At discharge and six months later, NIHSS scores continued to decrease in both groups, with the joint group being lower than the conventional group (P < .05); scores for all other items continued to increase, with the joint being higher than the conventional group (P < .05). Satisfaction with care was higher in the combined group than in the conventional group (P < .05). Conclusion: The complementary healthcare model combined with condition tracking can effectively promote the prognosis of rehabilitation of stroke patients, and has a positive effect in promoting the recovery of neurological and cognitive functions, strengthening self-efficacy, and improving the quality of life, which can be promoted in the clinic.

8.
Nat Commun ; 15(1): 1512, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38374204

RESUMO

This was a single-arm, multicenter phase 2 clinical trial (ChiCTR1900021726) involving advanced squamous non-small cell lung cancer (sq-NSCLC) patients undergoing 2 cycles of nab-paclitaxel/carboplatin and sintilimab (anti-PD-1), followed by sintilimab maintenance therapy. The median progression-free survival (PFS) was 11.4 months (95% CI: 6.7-18.1), which met the pre-specified primary endpoint. Secondary endpoints included objective response rate reaching 70.5% and a disease control rate of 93.2%, with a median duration of response of 13.6 months [95% CI: 7.0-not evaluable (NE)]. The median overall survival was 27.2 months (95% CI: 20.2-NE) with treatment-related adverse events grades ≥3 occurring in 10.9% of patients. Predefined exploratory endpoints comprised relationships between biomarkers and treatment efficacy, and the association between circulating tumor DNA (ctDNA) dynamics and PFS. Biomarker analysis revealed that the breast cancer gene 2, BMP/Retinoic Acid Inducible Neural Specific 3, F-box/WD repeat-containing protein 7, tyrosine-protein kinase KIT and retinoblastoma 1 abnormalities led to shorter PFS, while ctDNA negative at baseline or clearance at 2 cycles of treatment was associated with longer PFS (18.1 vs. 4.3 months). Taken together, sintilimab in combination with 2 cycles of nab-paclitaxel/carboplatin treatment produced encouraging PFS and better tolerability as first-line treatment for advanced sq-NSCLC.


Assuntos
Anticorpos Monoclonais Humanizados , Carcinoma Pulmonar de Células não Pequenas , Carcinoma de Células Escamosas , Neoplasias Pulmonares , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Carboplatina/uso terapêutico , Carboplatina/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética
9.
Materials (Basel) ; 17(2)2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276421

RESUMO

The heat transfer of a slab is significantly influenced by roll contact during the continuous casting process. The influence of roll contact calculation methods on the predicted heat transfer results has not been previously investigated. In this work, the non-uniform solidification of the wide-thick slab was studied with a 2D heat transfer model using real roll contact method (R. method) and equivalent roll contact method (E. method). The predicted slab surface temperature and shell thickness were verified with the measured results of the infrared camera and nail shooting experiments, respectively. Then, the predicted heat transfer results (including the slab surface temperature, mushy region length, and solidification end position) for the wide-thick slab with different thicknesses and different casting speeds were calculated using the E. method and R. method, and the influence of these two roll contact methods on the predicted heat transfer results was discussed for the first time. The results show that both these two roll contact methods could be applied to accurately predict the slab surface temperature without considering the transient temperature dips in the roll-slab contact regions. However, the deviation of the predicted mushy region length and solidification end position using the E. method are obvious. Compared with the R. method, the predicted mushy region length obtained using the E. method is larger and the solidification end obviously subsequently moves along the casting direction.

10.
BMC Cancer ; 24(1): 154, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38291411

RESUMO

The increasing cancer burden calls for reliably assessed changes in the hospitalizations for tumors over time and space in China. This study evaluated trends in hospitalization rate, in-hospital mortality, length of stay (LOS), and medical costs for malignant and benign neoplasms. Data were derived from China Health Statistical Yearbooks from 2004 to 2020. Temporal trends in hospitalization rates and in-hospital mortality rates were assessed through the Cochran-Armitage Test. We used the linear model with continuous variables to test for the trend. The malignant neoplasm hospitalization rate increased from 1.1‰ to 5.8‰ and the benign neoplasm increased from 1.0‰ to 2.0‰. The in-hospital mortality rate due to malignant neoplasm and benign neoplasm decreased from 5.11 to 2.87% (P for trend < 0.001) and 0.14-0.01% (P for trend < 0.001), respectively. Among all patients hospitalized with malignant neoplasm, the average cost per hospitalization significantly increased during the study period (P for trend < 0.001), adjusted for the Consumer Price Index. However, the average LOS gradually decreased (P for trend < 0.001). In line with the trend of malignant neoplasm, the average cost per hospitalization increased significantly among all patients hospitalized for benign neoplasm (P for trend < 0.001), and the average LOS showed a steady downward trend (P for trend < 0.001). We found upward trends in hospitalization rates, and medical costs in neoplasms. By contrast, substantial decreases in in-hospital mortality and LOS. The hospitalization rate gap between urban and rural areas is narrowed.


Assuntos
Neoplasias Encefálicas , Hospitalização , Humanos , Tempo de Internação , China/epidemiologia , Mortalidade Hospitalar
11.
Materials (Basel) ; 17(2)2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38276469

RESUMO

In this study, a three-dimensional segmented coupled model for continuous casting billets under combined mold and final electromagnetic stirring (M-EMS, F-EMS) was developed. The model was verified by comparing carbon segregation in billets with and without EMS through plant experiments. The findings revealed that both M-EMS and F-EMS induce tangential flow in molten steel, impacting solidification and solute distribution processes within the billet. For M-EMS, with operating parameters of 250A-2Hz, the maximum tangential velocity (velocity projected onto the cross-section) was observed at the liquid phase's edge. For F-EMS, with operating parameters of 250A-6Hz, the maximum tangential velocity occurred at fl=0.7. Furthermore, F-EMS accelerated heat transfer in the liquid phase, reducing the central liquid fraction from 0.93 to 0.85. M-EMS intensified the washing effect of molten steel on the solidification front, resulting in the formation of negative segregation within the mold. F-EMS significantly improved the centerline segregation issue, reducing carbon segregation from 1.15 to 1.02. Experimental and simulation results, with and without EMS, were in good agreement, indicating that M+F-EMS leads to a more uniform solute distribution within the billet, with a pronounced improvement in centerline segregation.

12.
J Ethnopharmacol ; 319(Pt 3): 117336, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-37907143

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: In traditional Chinese herbal medicine, rhubarb is said to remove accumulation with purgation, clearing heat, and discharging fire. Modern pharmacology has shown that rhubarb extract has a purgative effect when given to experimental animals in an appropriate dose. However, the active components and their mechanism of action are still not clearly defined. AIM OF THE STUDY: The current research aimed to evaluate the synergistic stool-softening effects and explore the action mechanism of rhubarb free anthraquinones (RhA) and their monomers on constipation in rats. MATERIALS AND METHODS: A rat model of water deficit-induced constipation was established to induce constipation, and these rats were treated with RhA and its monomers. ELISA, histopathology, immunohistochemistry, qPCR and Western blotting based on network pharmacology and molecular docking were conducted to explore the possible mechanism of action of RhA and its monomers. RESULTS: RhA, aloe-emodin, rhein, and chrysophanol showed stool-softening activity, and the combination of aloe-emodin and rhein had the strongest softening effect on faecal pellets. Aloe-emodin, rhein, and chrysophanol significantly increased the serum levels of vasoactive intestinal peptide (VIP), motilin (MTL), and substance P (SP), upregulated the expression of VIP, cyclase-associated protein 1 (CAP1), protein kinase A (PKA), cystic fibrosis transmembrane conductance regulator (CFTR), aquaporin 3 (AQP3), aquaporin 4 (AQP4), and aquaporin 8 (AQP8), decreased the expression of epithelial sodium channel (ENaC) and Na+/H+ exchanger 3 (NHE3), and reduced the colonic tissue concentration of Na+-K+-ATPase in the constipated rats. Osmolality of colonic fluid in model rats treated by RhA, aloe-emodin, rhein, and chrysophanol was increased. CONCLUSION: Aloe-emodin, rhein, and chrysophanol were the stool-softening components of the RhA extract, and there were certain drug-interactions between the components. RhA upregulated VIP expression, activated the cyclic adenosine monophosphate protein kinase A (cAMP/PKA) pathway, and further stimulated CFTR expression while inhibiting NHE3 and ENaC expression, resulting in a hypertonic state in the colonic lumen. Water transport could then be driven by an osmotic gradient, which in turn led to the upregulation of AQP3, AQP4, and AQP8 expression. In addition, RhA likely improved gastrointestinal motility by increasing serum VIP, SP, and MTL concentrations, thus promoting faecal excretion.


Assuntos
Emodina , Rheum , Animais , Ratos , Regulador de Condutância Transmembrana em Fibrose Cística , Simulação de Acoplamento Molecular , Trocador 3 de Sódio-Hidrogênio , Constipação Intestinal/induzido quimicamente , Constipação Intestinal/tratamento farmacológico , Antraquinonas/farmacologia , Antraquinonas/uso terapêutico , Aquaporina 3 , Proteínas Quinases Dependentes de AMP Cíclico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico
13.
Materials (Basel) ; 16(23)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38068206

RESUMO

Carbon segregation is the major and classical internal defect in the continuous casting process of carbon steel. Based on the combined electromagnetic stirring equipment for new billet in a steel plant, China, the influence of combined electromagnetic stirring (M-EMS + F-EMS) on the carbon segregation of 300 mm × 340 mm special-shaped billet was studied via numerical simulation and on-site industrialization tests. The Lorentz force and carbon solute distribution were simulated under different EMS parameters. The formation mechanism of the carbon segregation of medium carbon steel with different combined electromagnetic stirring processes was analyzed. The results show that: (1) with the combined action of "solute flushing" effect and gravity, the carbon concentration in the loose side of the medium carbon steel casting billet is gradually lower than the fixed side, while the carbon concentration on the fixed side gradually accumulates more; and (2) under the action of combined electromagnetic stirring, the segregation index of casting billet could be controlled to remain between 0.96-1.05 and shows an increasing change in solidification from the skin to the center. When the current and frequency of M-EMS are 250 A and 2.0 Hz and the F-EMS are 180 A and 8.0 Hz, the carbon segregation defects in the special-shaped (300 mm × 340 mm) casting billet can be significantly improved.

14.
Plant Physiol ; 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38084893

RESUMO

Maintaining proper flower size is vital for plant reproduction and adaption to the environment. Petal size is determined by spatiotemporally regulated cell proliferation and expansion. However, the mechanisms underlying the orchestration of cell proliferation and expansion during petal growth remains elusive. Here, we determined that the transition from cell proliferation to expansion involves a series of distinct and overlapping processes during rose (Rosa hybrida) petal growth. Changes in cytokinin content were associated with the transition from cell proliferation to expansion during petal growth. RNA sequencing identified the AP2/ERF transcription factor gene RELATED TO AP2 4-LIKE (RhRAP2.4L), whose expression pattern positively associated with cytokinin levels during rose petal development. Silencing RhRAP2.4L promoted the transition from cell proliferation to expansion and decreased petal size. RhRAP2.4L regulates cell proliferation by directly repressing the expression of KIP RELATED PROTEIN 2 (RhKRP2), encoding a cell cycle inhibitor. In addition, we also identified BIG PETALub (RhBPEub) as another direct target gene of RhRAP2.4L. Silencing RhBPEub decreased cell size, leading to reduced petal size. Furthermore, the cytokinin signaling protein ARABIDOPSIS RESPONSE REGULATOR 14 (RhARR14) activated RhRAP2.4L expression to inhibit the transition from cell proliferation to expansion, thereby regulating petal size. Our results demonstrate that RhRAP2.4L performs dual functions in orchestrating cell proliferation and expansion during petal growth.

15.
Materials (Basel) ; 16(24)2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38138698

RESUMO

Impurity elimination in tundishes is an essential metallurgical function in continuous casting. If inclusions in a tundish cannot be effectively removed, their presence will have a serious impact on the quality of the bloom. As a result, this research investigates the locations of inclusion particles in a six-strand induction-heating tundish in depth, combining the flow, temperature, and inclusion trajectories of molten steel under electromagnetic fields. The results show that a pinch effect occurred in the induction-heating tundish, and a rotating magnetic field formed in the channel, with a maximum value of 0.158 T. The electromagnetic force was directed toward the center of the axis, and its numerical distribution corresponds to the magnetic flux density distribution, with a maximum value of 2.11 × 105 N/m3. The inclusion particles' movement speed accelerated as the molten steel's temperature rose, and their distribution in the channel was identical to the rotating flow field distribution. When the steel's temperature rose from 1750 K to 1850 K, the removal percentage of inclusion particles in the discharge chamber rose by 9.20%, the removal rate at the outlet decreased from 8.00% to 3.00%, and the adhesion percentage of inclusion particles in the channel decreased from 48.40% to 44.40%.

16.
Cell Mol Biol (Noisy-le-grand) ; 69(7): 98-103, 2023 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-37715418

RESUMO

Exercise stress can cause reversible myocardial ischemia in people with coronary artery disease (CAD). On the other hand, the new troponin biomarker with high sensitivity can detect faster and small amounts of troponin in blood circulation. The present study aimed to investigate the serum troponin level following exercise stress and the result of nuclear heart scans as the gold standard. For this purpose, 93 patients with stable angina and no history of known CAD and organic disease were included in this cross-sectional study. The serum level of the highly sensitive cardiac troponin I (hs-cTnI) was measured 75 minutes after the peak of the exercise test and reached at least 85% of the maximum heart rate. It was compared with the rate of reversible myocardial ischemia based on the nuclear heart scan, the three-month prognosis and the persistence of chest pain were investigated. Also, the expression level of the cTnI gene was evaluated by real-time PCR technique. The results showed that the average age of the patients was 58.9+12.4 years, and 62 (66.66%) patients were female. Reversible myocardial ischemia was observed in 31 patients. The relationship between hs-cTI level and the rate of reversible ischemia cases was significant (p = 0.0041). Also, the cTnI gene expression showed the same results as the serum level. According to the heart nuclear scan report, the hs-cTnI value above 1.6ng/dl had a specificity of 72% and sensitivity of 66%, a positive predictive value of 53%, and a negative predictive value of 78%. There was no significant relationship between hs-cTnI level and prognosis and the continuation of chest pain in patients after three months. Generally, the serum level of high-sensitivity cardiac troponin was higher after exercise in the group with reversible myocardial ischemia.


Assuntos
Angina Estável , Doença da Artéria Coronariana , Isquemia Miocárdica , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Masculino , Troponina I/genética , Estudos Transversais , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/genética , Isquemia Miocárdica/diagnóstico por imagem , Isquemia Miocárdica/genética , Dor no Peito , Angina Estável/diagnóstico por imagem , Angina Estável/genética , Expressão Gênica
17.
Materials (Basel) ; 16(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37569957

RESUMO

The quality of the bloom will be impacted by the non-metallic impurities in the molten steel in the tundish, which will reduce the plasticity and fatigue life of the steel. In this research, a mathematical model of a six-flow double-channel T-shaped induction heating tundish was established, the effects of induction heating conditions on the removal of inclusions in the tundish were investigated, and the impact of various inclusion particle sizes on the removal effect of inclusions under induction heating was explored. The results show that the Residence Time Distribution (RTD) curve produced through numerical simulation and physical simulation is in good agreement. The reduction of inclusion particles in the channel is made affordable by the dual-channel induction heating technique. As the diameter of inclusion particles increases from 10 µm to 50 µm, the probability of inclusion particles being removed from the channel gradually decreases from 70.9% to 56.1%.

18.
Materials (Basel) ; 16(16)2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37629822

RESUMO

Electromagnetic stirring (M-EMS) has been extensively applied in continuous casting production to reduce the quality defects of casting billets. To investigate the effect of continuous casting electromagnetic stirring on billet segregation, a 3D multi-physics coupling model was established to simulate the internal heat, momentum, and solute transfer behavior, to identify the effect of M-EMS on the carbon segregation of a continuous casting square billet of 200 mm × 200 mm. The results show that M-EMS can move the high-temperature zone upward, which is favorable for the rapid solidification of the billet, and can promote the rotational flow of the molten steel in the horizontal direction. When the electromagnetic stirring current is varied in the range of 0-500 A, the degree of carbon segregation first decreases and then increases, with the best control of segregation at 300 A. In the frequency range of 3-5 Hz, the degree of carbon segregation degree increases with frequency. Meanwhile, the simulation and experimental results show that 3 Hz + 300 A is the best electromagnetic stirring parameter for improving the carbon segregation of casting billets with a size of 200 mm × 200 mm. So, a reasonable choice of the M-EMS parameters is crucial for the quality of the billet.

19.
Ultrason Sonochem ; 98: 106526, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37515909

RESUMO

The self-assembled structures of coix seeds affected the enzymatic efficiency and doesn't facilitate the release of more active peptides. The influence of heating combined with ultrasound pretreatment (HT + US) on the structure, enzymatic properties and hydrolysates (CHPs) of coix seed prolamin was investigated. Results showed that the structural of coix seed prolamins has changed after HT + US, including increased surface hydrophobicity, reduced α-helix and random coil content, and a decrease in particle size. So that, leads to changes in thermodynamic parameters such as an increase in the reaction rate constant and a decrease in activation energy, enthalpy and enthalpy. The fractions of <1000 Da, degree of hydrolysis and α-glucosidase inhibitory were increased in the HT + US group compared to single pretreatment by 0.68%-17.34%, 12.69%-34.43% and 30.00%-53.46%. The peptide content and α-glucosidase inhibitory activity of CHPs could be maintained at 72.21 % and 57.97 % of the initial raw materials after in vitro digestion. Thus, the findings indicate that HT + US provides a feasible and efficient approach to can effectively enhance the enzymatic hydrolysis efficiency and hypoglycaemic efficacy of CHPs.


Assuntos
Coix , Prolaminas/análise , Prolaminas/química , Hidrólise , Coix/química , Temperatura Alta , alfa-Glucosidases , Peptídeos/farmacologia , Peptídeos/química , Sementes/química
20.
Front Neurol ; 14: 1144900, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37273697

RESUMO

Introduction: Patients with chronic low back pain (CLBP) exhibit changes in proprioceptive weighting and impaired postural control. This study aimed to investigate proprioceptive weighting changes in patients with CLBP and their influence on posture control. Methods: Sixteen patients with CLBP and 16 healthy controls were recruited. All participants completed the joint reposition test sense (JRS) and threshold to detect passive motion test (TTDPM). The absolute errors (AE) of the reposition and perception angles were recorded. Proprioceptive postural control was tested by applying vibrations to the triceps surae or lumbar paravertebral muscles while standing on a stable or unstable force plate. Sway length and sway velocity along the anteroposterior (AP) and mediolateral (ML) directions were assessed. Relative proprioceptive weighting (RPW) was used to evaluate the proprioception reweighting ability. Higher values indicated increased reliance on calf proprioception. Results: There was no significant difference in age, gender, and BMI between subjects with and without CLBP. The AE and motion perception angle in the CLBP group were significantly higher than those in the control group (JRS of 15°: 2.50 (2.50) vs. 1.50 (1.42), JRS of 35°: 3.83 (3.75) vs. 1.67 (2.00), pJRS < 0.01; 1.92 (1.18) vs. 0.68 (0.52), pTTDPM < 0.001). The CLBP group demonstrated a significantly higher RPW value than the healthy controls on an unstable surface (0.58 ± 0.21 vs. 0.41 ± 0.26, p < 0.05). Under the condition of triceps surae vibration, the sway length (pstable < 0.05; punstable < 0.001), AP velocity (pstable < 0.01; punstable < 0.001) and ML velocity (punstable < 0.05) had significant group main effects. Moreover, when the triceps surae vibrated under the unstable surface, the differences during vibration and post vibration in sway length and AP velocity between the groups were significantly higher in the CLBP group than in the healthy group (p < 0.05). However, under the condition of lumbar paravertebral muscle vibration, no significant group main effect was observed. Conclusion: The patients with CLBP exhibited impaired dynamic postural control in response to disturbances, potentially linked to changes in proprioceptive weighting.

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