1,278 research outputs found
Lattice Boltzmann methods for multiphase flow and phase-change heat transfer
Over the past few decades, tremendous progress has been made in the development of particle-based discrete simulation methods versus the conventional continuum-based methods. In particular, the lattice Boltzmann (LB) method has evolved from a theoretical novelty to a ubiquitous, versatile and powerful computational methodology for both fundamental research and engineering applications. It is a kinetic-based mesoscopic approach that bridges the microscales and macroscales, which offers distinctive advantages in simulation fidelity and computational efficiency. Applications of the LB method are now found in a wide range of disciplines including physics, chemistry, materials, biomedicine and various branches of engineering. The present work provides a comprehensive review of the LB method for thermofluids and energy applications, focusing on multiphase flows, thermal flows and thermal multiphase flows with phase change. The review first covers the theoretical framework of the LB method, revealing certain inconsistencies and defects as well as common features of multiphase and thermal LB models. Recent developments in improving the thermodynamic and hydrodynamic consistency, reducing spurious currents, enhancing the numerical stability, etc., are highlighted. These efforts have put the LB method on a firmer theoretical foundation with enhanced LB models that can achieve larger liquid-gas density ratio, higher Reynolds number and flexible surface tension. Examples of applications are provided in fuel cells and batteries, droplet collision, boiling heat transfer and evaporation, and energy storage. Finally, further developments and future prospect of the LB method are outlined for thermofluids and energy applications
Biological roles of crop NADP-malic enzymes and molecular mechanisms involved in abiotic stress
The abiotic stress tolerance of plants is very important for plant growth, development, survival and functional performance. NADP-ME is one of the most important enzymes in plants. Studying the role that NADP-malic enzyme plays in many metabolisms may help researchers improve the plant abiotic tolerance. The studies on NADP-ME in plants focus on its activity under different stresses. The regulation of NADP-ME gene expression in transgenic plants and the mechanism about abiotic stress resistance are less. In this paper, we reviewed the characteristics of the activity and genes expression of NADP-ME under drought, salt and temperature stresses. We also focused on the role of NADP-ME when it resists these varying stresses and the mechanism on how it performs.Key words: Plant NADP-malic enzyme, abiotic stress, gene expression, molecular mechanism
Diffraction problems for quasilinear parabolic systems with boundary intersecting interfaces
Stability of Unilateral Posterior Crossbite Correction in the Mixed Dentition
- an RCT-study with 3-year Follow-Up.
Aim: To compare and evaluate long-term stability of crossbite correction with Quad Helix or expansion plate in the mixed dentition.
Methods: In this RCT-study 35 patients with unilateral posterior crossbite were randomized to be treated with either Quad Helix or expansion plate. The inclusion criteria were: mixed dentition, unilateral posterior crossbite, no sucking habits or previous orthodontic treatment. Stability was evaluated after 3 years by study cast measurements. Twenty subjects with normal occlusion were included as controls. Success rate, maxillary and mandibular transverse dimensions, overjet, overbite and arch length were registered.
Results: Stability was equal for the two treatment methods. Small, albeit significant, differences between the groups were assessed with reference to transverse dimensions. No significant difference was seen for overjet and overbite. The treated patients never reached the same transversal width as the normal control group.
Conclusions: The long-term stability of posterior crossbite correction with Quad helix and expansion plate was equal. The maxillary width was greater in the control group than the treated groups
Analysis of Body Mass Index and Clinicopathological Factors in Patients with Papillary Thyroid Carcinoma
Wei Yan,1 Xue Luo,1 Qing-Jun Gao,1 Bing-Feng Chen,2 Hui Ye1 1Department of Thyroid Surgery, Affiliated Hospital of Guizhou Medical University, Guiyang, 550001, People’s Republic of China; 2Guizhou Medical University, Guiyang, 550001, People’s Republic of ChinaCorrespondence: Hui Ye, Department of Thyroid Surgery, Affiliated Hospital of Guizhou Medical University, No. 28 of Guiyi Street, Yunyan District, Guiyang, 550001, People’s Republic of China, Tel +86-85186772361, Fax +86-85186773426, Email [email protected]: To analyze the correlation between body mass index (BMI) and clinicopathological factors of papillary thyroid cancer (PTC).Methods: The clinical data of patients with PCT who were hospitalized in the Department of Thyroid Surgery of the Affiliated Hospital of Guizhou Medical University from March 2023 to September 2023 were retrospectively collected, including age, gender, height, weight, BMI, v-raf murine sarcoma viral oncogene homolog B (BRAF) gene mutation, tumor size, multifocus, Hashimoto’s thyroiditis, lymph node metastasis and other clinicopathological factors. According to the World Health Organization (WHO) definition for Asian population, BMI≥ 25kg/m2 was obese group, 23≤BMI≤ 24.9kg/m2 was overweight group, 18.5≤BMI≤ 22.9kg/m2 was normal weight group, and BMI≤ 18.5kg/m2 was low weight group. The clinicopathological factors of overweight and obese patients with PTC were analyzed.Results: A total of 164 PTC patients were included, with an average BMI of (24.44± 3.57) kg/m2. Age of overweight and obese PTC patients (Z=1.978, p=0.083); Gender of overweight and obese PTC patients (χ2 value: 11.570, p=0.004); Tumor size in overweight and obese PTC patients (Z=0.894, p=0.411); BRAF gene mutation in overweight and obese PTC patients (χ2 value: 1.452, p =0.623); Multifocal lesions were found in overweight and obese patients (χ2 value: 1.653, p =0.201). Hashimoto’s thyroiditis was found in overweight and obese PTC patients (χ2 value: 1.147, p=0.298). Overweight and obese patients with PTC had lymph node metastasis (χ2 value: 1.690, p =0.251).Conclusion: Overweight and obesity in PTC patients are correlated with male, but not with age, tumor size, BRAF mutation, multifocality, Hashimoto’s thyroiditis and lymph node metastasis.Keywords: papillary thyroid carcinoma, body mass index, clinicopathological factors, correlation analysi
Anti-HIV-1 activity of cellulose acetate phthalate: Synergy with soluble CD4 and induction of "dead-end" gp41 six-helix bundles
BACKGROUND: Cellulose acetate phthalate (CAP), a promising candidate microbicide for prevention of sexual transmission of the human immunodeficiency virus type 1 (HIV-1) and other sexually transmitted disease (STD) pathogens, was shown to inactivate HIV-1 and to block the coreceptor binding site on the virus envelope glycoprotein gp120. It did not interfere with virus binding to CD4. Since CD4 is the primary cellular receptor for HIV-1, it was of interest to study CAP binding to HIV-1 complexes with soluble CD4 (sCD4) and its consequences, including changes in the conformation of the envelope glycoprotein gp41 within virus particles. METHODS: Enzyme-linked immunosorbent assays (ELISA) were used to study CAP binding to HIV-1-sCD4 complexes and to detect gp41 six-helix bundles accessible on virus particles using antibodies specific for the α-helical core domain of gp41. RESULTS: 1) Pretreatment of HIV-1 with sCD4 augments subsequent binding of CAP; 2) there is synergism between CAP and sCD4 for inhibition of HIV-1 infection; 3) treatment of HIV-1 with CAP induced the formation of gp41 six-helix bundles. CONCLUSIONS: CAP and sCD4 bind to distinct sites on HIV-1 IIIB and BaL virions and their simultaneous binding has profound effects on virus structure and infectivity. The formation of gp41 six-helical bundles, induced by CAP, is known to render the virus incompetent for fusion with target cells thus preventing infection
Resonances in and
A partial wave analysis is presented of and
from a sample of 58M events in the BES II detector. The
is observed clearly in both sets of data, and parameters of the
Flatt\' e formula are determined accurately: (stat)
(syst) MeV/c, MeV/c, . The data also exhibit a strong peak
centred at MeV/c. It may be fitted with and a
dominant signal made from interfering with a smaller
component. There is evidence that the signal is
resonant, from interference with . There is also a state in with MeV/c and
MeV/c; spin 0 is preferred over spin 2. This state, , is
distinct from . The data contain a strong peak due to
. A shoulder on its upper side may be fitted by interference
between and .Comment: 17 pages, 6 figures, 1 table. Submitted to Phys. Lett.
Measurement of the Branching Fraction of J/psi --> pi+ pi- pi0
Using 58 million J/psi and 14 million psi' decays obtained by the BESII
experiment, the branching fraction of J/psi --> pi+ pi- pi0 is determined. The
result is (2.10+/-0.12)X10^{-2}, which is significantly higher than previous
measurements.Comment: 9 pages, 8 figures, RevTex
Search for K_S K_L in psi'' decays
K_S K_L from psi'' decays is searched for using the psi'' data collected by
BESII at BEPC, the upper limit of the branching fraction is determined to be
B(psi''--> K_S K_L) < 2.1\times 10^{-4} at 90% C. L. The measurement is
compared with the prediction of the S- and D-wave mixing model of the
charmonia, based on the measurements of the branching fractions of J/psi-->K_S
K_L and psi'-->K_S K_L.Comment: 5 pages, 1 figur
First Measurements of eta_c Decaying into K^+K^-2(pi^+pi^-) and 3(pi^+pi^-)
The decays of eta_c to K^+K^-2(pi^+pi^-) and 3(pi^+pi^-) are observed for the
first time using a sample of 5.8X10^7 J/\psi events collected by the BESII
detector. The product branching fractions are determined to be B(J/\psi-->gamma
eta_c)*B(eta_c-->K^+K^-pi^+pi^-pi^+pi^-)=(1.21+-0.32+-
0.23)X10^{-4}, and (J/\psi-->gamma eta_c)*
B(eta_c-->pi^+pi^-pi^+pi^-pi^+pi^-)= (2.59+-0.32+-0.48)X10^{-4}. The upper
limit for eta_c-->phi pi^+pi^-pi^+pi^- is also obtained as B(J/\psi-->gamma
eta_c)*B(eta_c--> phi pi^+pi^-pi^+pi^-)< 6.03 X10^{-5} at the 90% confidence
level.Comment: 11 pages, 4 figure
- …