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In order to obtain the spatial directivity of ship radiated noise at far field in shallow water, a new method is presented to compute the corresponding sound field distribution at far field. Firstly the sound pressure data measured by hydrophone array at near field was used to obtain the equivalent intensity and positions of multi-pole structure model for ship radiated noise, then the spatial directivity of far field radiated noise is computed by normal modes. A comparison between simulation results of far field spatial directivity of ship noise obtained by this method and the result obtained from direct computation using assumed data of sound sources show that the method presented in this paper can give an acceptable spatial directivity of far field. [ABSTRACT FROM AUTHOR]

The sound baffle is a useful component for the sonar design. According to the different requirement, it's the keyboard to optimize the physical and structural parameters of the baffle. A Genetic algorithm, as an efficient optimization method, is used widely in the engineering optimization. However, the composition of chromosome, the coding form and the definition of cost function would seriously influence the performance of genetic algorithm because its calculation doesn't depend on the external information. According to the aim at maintain the reflection coefficients minimized and uniformed in the scopes of both definite incident frequencies and angles, the optimization method of parameters of layered composite sound baffle based on the genetic algorithm will be presented. In this algorithm, the chromosome coding based on transfer matrix and the cost function based on the statistic principle are proposed. The dependability and validity of the algorithm are proved and the influence led by changing the cost function on the result from the optimum algorithm is analyzed with the simulation calculation. [ABSTRACT FROM AUTHOR]

Objectives: To study the association of β2-drenergic receptor ( ADRB2 ) regulatory region single nucleotides polymorphism (SNP)/haplotypes at rs11168070, rs17108803, rs2053044, rs12654778, rs11959427, and rs2895795 loci with childhood asthma., Methods: A total of 143 children with asthma who attended the hospital from October 2016 to October 2020 were enrolled as the asthma group, among whom 61 children had mild symptoms (mild group) and 82 children had moderate-to-severe symptoms (moderate-to-severe group). A total of 137 healthy children were enrolled as the control group. Peripheral venous blood samples were collected from the two groups. The SNaPshot SNP technique was used to analyze the SNP and haplotypes of the ADRB2 regulatory region at rs11168070, rs17108803, rs2053044, rs12654778, rs11959427, and rs2895795 loci in all children. The asthma group and the control group were compared in terms of the association of ADRB2 regulatory region SNP and haplotypes at the above six loci with susceptibility to asthma and severity of asthma., Results: Polymorphisms were observed in the ADRB2 regulation region at the above six loci in both the asthma group and the control group, with significant differences between the two groups in the distribution of genotype and allele frequencies at rs2895795 (-1429T /A), rs2053044(-1023G/A), and rs12654778 (-654G/A) loci ( P <0.05). Linkage disequilibrium of SNP was observed at the six loci of the ADRB2 regulatory region.The haplotypes of TATGCT, TATGGC, and AGTGCT were associated with susceptibility to childhood asthma, among which TATGCT and TATGGC were risk factors for childhood asthma ( OR =1.792 and 1.946 respectively, P <0.05), while AGTGCT was a protective factor ( OR =0.523, P <0.05)., Conclusions: SNP/haplotype of the ADRB2 regulatory region is associated with the susceptibility to childhood asthma. The haplotypes of TATGCT and TATGGC formed by such SNP/haplotype are risk factors for childhood asthma, while AGTGCT is a protective factor.

Objective: To investigate the effects of combination treatment of photodynamic therapy (PDT) based on photosensitizer chlorin e6 (Ce6) and antibiotic agent tinidazole (TNZ) against periodontitis both in vitro and in vivo . Methods: The Sprague-Dewley (SD) rat periodontitis model was constructed using the method of orthodontic wire ligation. After successful modeling, SD rats were randomly divided into the following 6 groups (3 rats in each group): positive control (Ctrl+), Ce6, TNZ, a mixture of Ce6 and TNZ (Ce6/TNZ), Ce6 with laser irradiation (Ce6+L), a mixture of Ce6 and TNZ with laser irradiation (Ce6/TNZ+L). Methyl thiazolyl tetrazolium (MTT) assay was used to assess the cytotoxic activities of Ce6 (concentration range: 0-20 mg/L), TNZ (concentration range: 0-16.6 mg/L) and their mixture (Ce6/TNZ) in mouse fibroblast L929 cells. Fluorescence probe method was applied to measure the production of reactive oxygen species in the dental plaque biofilms after various treatments with and without 5-minute laser irradiation at 635 nm at a power density of 0.5 W/cm 2 (Ce6+L and Ce6/TNZ+L groups), thus to evaluate the PDT performances. Cell counting kit-8 (CCK-8) and live/dead staining were used to assess the antibacterial activity in each of the groups and the combination index (CI) of PDT combined with TNZ was calculated subsequently. Flow cytometry was utilized to detect the apoptosis-inducing effects of these treatments in macrophage RAW264.7 cells after processing with the apoptosis detection kit. The inhibitory effects of various treatments on the absorption of alveolar bone of SD rats were further evaluated in the periodontitis rats by using the micro-CT. Results: The survival rates of L929 cells in the preset concentration range were all above 90% in Ce6, TNZ and Ce6/TNZ groups. Upon laser irradiation, the plaque biofilms in Ce6 and Ce6/TNZ groups showed significant green fluorescence, indicating that large amounts of reactive oxygen species were triggered and generated significantly in the dental plaque biofilms. However, the survival rates of dental plaque microorganisms in 5 Ce6/TNZ concentrations were (85.4±5.5)%, (76.0±8.9)%, (61.7±0.6)%, (56.3±2.6)% and (43.5±0.6)% respectively, which were significantly lower than that in Ce6 only and TNZ only groups ( P <0.01). The CI levle of each drug concentration group was less than 1.0, which showed a significant synergistic antibacterial efficiency. Stronger apoptotic activities were observed in Ce6+L and Ce6/TNZ+L groups compared with those in Ce6 only and Ce6/TNZ only groups ( P <0.01). In periodontitis rats, Ce6/TNZ combined laser irradiation could effectively inhibit the absorption of alveolar bone. The alveolar bone volume and the ratio of bone volume and tissue volume were (1.49±0.07) mm 3 and (47.08±0.71)%, respectively. The distances between cementoenamel junction to alveolar bone crest on buccal and palatal sites decreased to (2.13±0.07) mm and (1.94±0.10) mm respectively, showing a high inhibition efficiency. Conclusions: Ce6-mediated PDT combined with TNZ possessed notable synergistic effects against periodontitis, reflecting in the efficient antibacterial effect, the apoptosis-inducing action on macrophages, and the inhibitory efficacy on the alveolar bone absorption in vivo .

Objective: The optimal operative strategy in patients with asymptomatic severe carotid artery stenosis undergoing coronary artery bypass grafting (CABG) is unknown. We sought to investigate the safety of carotid arterial shunting during simultaneous CABG and carotid endarterectomy (CEA). Methods: The clinical data of patients undergoing synchronous combined CEA and CABG in the First Hospital of China Medical University between March 2017 and July 2019 was retrospectively studied. Patients with asymptomatic severe carotid artery stenosis ≥70% according to NASCET (North American Symptomatic Carotid Endarterectomy Trial) were required CABG surgery. During conventional CEA, carotid arterial shunting was used in all cases. Results: Ten patients were recruited. The average clamping time of carotid artery was 5 minutes. The average follow-up time was 10 months. We did not observe stroke, cerebral hyper perfusion syndrome, death and carotid restenosis. Conclusions: Carotid arterial shunting during synchronous combined CEA and CABG was helpful for obtaining good curative effect.

Thirteen stationary phases comprising a polyvinyl imidazolium ionic liquid (IL) in which cations containing propyl, butyl, nonyl, ethyl-phenyl, or cyan methyl functional groups are paired with bis(trifluoromethanesulfonyl) imide ([NTf 2 ] - ), trifluoromethanesulfonate ([TFO] - ), and hexafluorophosphate ([PF 6 ] - ) were synthesized and directly coated inside capillary fused silica tubing for use in gas chromatography. The relationship between the structure of the ILs and the McReynolds constant, thermal stability, and retention behavior of the test compound on the prepared fused silica columns was examined and discussed. The influence of the cationic substituents on retention performance of stationary phases was also studied. The variation in the retention index of the test compound with temperature was also investigated. The results indicated that the synthesized ILs have strong polarity, and that their retention performance is closely related to not only the properties of the cationic substituent but also the structure of the substituted groups and the anion. In the temperature range investigated, the variation in the retention index of the tested compounds was the same as that of conventional chromatographic stationary phases.

Objective: To objectively assess and compare comprehensive optical quality among adults at different ages., Methods: In this cross-sectional study, there were 432 subjects (432 eyes) aged from 20 to 70 years with best corrected visual acuity (BCVA) better than 4.9. If both eyes of a subject had equal BCVA, one eye was selected randomly. Otherwise, the eye with better BCVA was chosen. The patients were divided into 5 groups at an age interval of 10 years. The optical quality analysis system Ⅱ (OQASⅡ) was used to measure the following optical quality parameters: the modulation transfer function cutoff frequency (MTFcutoff), the Strehl ratio, three OQAS values (OV100%, OV20%, and OV9%), and the objective scatter index (OSI). Each optical quality parameter was compared among different groups by One-way ANOVA., Results: In the groups of 20-29 years, 30-39 years, 40-49 years, 50-59 years, and 60-69 years, the MTFcutoff was (43.91±7.43), (40.93±9.92), (37.16±9.04), (36.69±7.87), and (28.52±8.31) cpd, respectively; the Strehl ratio was 0.26±0.06, 0.24±0.06, 0.20±0.05, 0.20±0.04, and 0.16±0.04, respectively; the OV100% was 1.47±0.24, 1.36±0.33, 1.24±0.30, 1.22±0.26, and 0.96±0.28, respectively; the OV20% was 1.51±0.33, 1.40±0.38, 1.22±0.36, 1.20±0.28, and 0.91±0.32, respectively; the OV9% was 1.14±0.26, 1.41±0.40, 1.20± 0.37, 1.18±0.28, and 0.89±0.28, respectively; the OSI was 0.42±0.24, 0.53±0.32, 0.54±0.34, 0.54±0.26, and 1.06±0.56, respectively. There were significant differences in the mean values of MTFcutoff, Strehl ratio, OV100%, and OV20% among groups (P<0.05), except for the groups of 40-49 years and 50-59 years (P>0.05). The OV9% was significantly different among groups (P<0.05), except for the groups of 20-29 years, 40-49 years, and 50-59 years (P>0.19). The OSI was also significantly different among groups (P<0.05), except for the groups of 30-39 years, 40-49 years, and 50-59 years (P>0.70)., Conclusion: The comprehensive optical quality in the young healthy population is better than the old, except for a plateau in the middle-aged population.

Objective: To detect the rhoptry and surface proteins of invasive stages of Plasmodium yoelii and P. berghei with monoclonal antibodies., Methods: Subcellular localization of antigens was detected by IFA. The antigens of different stages of the two species malaria parasites were analyzed by Western blotting., Results: The antigens of rhoptry are very complicated. There are similar epitopes of the rhoptry proteins detected between the two species of Plasmodium. The similar epitopes were also detected between ookinetes and merozoites of P. yoelii, and ookinete antigens between the two species. But there are different antigens detected between merozoites and ookinetes in P. yoelii. The sporozoite surface antigen of P. yoelii was not detected in the ookinetes and merozoites in the same species., Conclusion: There are similar epitopes in the rhoptry and surface antigens of different stages and different species of rodent malaria parasites. There are also distinct antigens among them.

Objective: To study tumor angiogenesis in primary lung cancer and its relation with lymph node metastasis, tumor cell apoptosis, and cell proliferation., Methods: Intratumor microvessel was detected by factor VIII polyclonal antibody using immunohistochemistry. Tumor cell apoptosis was detected by TUNEL method. Cell proliferation was analyzed by flow cytometry., Results: Intratumor microvessel density (MD) was significantly lower in stage I lung cancer than in stage II and stage III (P < 0.01). MD was significantly higher in the tumors with lymph node metastasis (P < 0.01). With the increase in MD, there would be a 1.2-fold increase in the risk of lymph node metastasis (P < 0.01). With the increase of MD, apoptosis index (AI) of the tumor significantly decreased, but no relationship between MD and cell proliferation index (PI) was observed., Conclusion: Tumor angiogenesis promotes growth and metastasis of lung cancer. Tumor angiogenesis also can inhibit the apoptosis of lung cancer.

Objective: To study the expression levels of vascular endothelial growth factor (VEGF) and its relation with intratumoral microvessel density (MD), cellular proliferation activity (PI), and lymph node metastasis of primary lung cancer., Methods: Surgical samples of 53 patients with primary lung cancer were measured. The VEGF was immunofluorescence stained with VEGF polyclonal antibody. The propidium iodide was used to stain cellular DNA. VEGF expression levels and DNA content were analyzed quantitatively using flow cytometry. Intratumoral microvessel density was detected by factor VIII polyclonal antibody using immunohistochemistry., Results: VEGF expression levels (FI) were high in lung cancer (1.3 +/- 0.6, positive ratio 73.58%). The cellular proliferation activity (PI) in VEGF-positive tumors was significantly higher than that in VEGF-negative tumors (29.8% +/- 9.2% vs 18.7% +/- 6.5%, P < 0.01). The intratumoral microvessel density (MD) in VEGF-positive tumors was higher than that in VEGF-negative tumors (19.4 +/- 11.3 vs 12.3 +/- 8.0, P < 0.05). No association was found between the MD and PI (r = 0.169, P > 0.05). The VEGF expression levels in lung cancer tissues with lymph node metastasis (n = 33) were significantly higher than that in those without lymph node metastasis (n = 20) (1.5 +/- 0.6 vs 1.0 +/- 0.5, P < 0.01)., Conclusion: VEGF plays an important role in the growth and metastasis of lung cancer.