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By taking the spring mass damping system of the single degree of freedom excited by the eccentric rotor as the object， Sommerfeld effect of the non-ideal vibration system driven by the AC motor as the prime motor was studied. The electromagnetic torque formula of the AC motor was introduced to establish the dynamic model of the vibration system driven by the AC motor. Based on the small parameter averaging method， the approximate solution of the vibration system response was obtained. According to the solution， the torque balance equation of the motor in steady-state motion was derived. Numerical analysis illustrated that the angular velocity of the motor and the frequency of power will jump in the resonance region， and the relationship between the amplitude of the system and the frequency of power has hard non-linear characteristics. The mechanism of these phenomena was explained by the stability judgment conditions， and the correctness of the theoretical method was verified by the numerical time domain simulation. Finally， the key structural parameters were discussed quantitatively and qualitatively. [ABSTRACT FROM AUTHOR]

Objective To compared the effects of washing and filtering treatment modes with different apertures on the survival rate and vascularization of transplanted plants after particle fat transplantation. Methods From October 2018 to April 2019, granular adipose tissue was obtained by manual liposuction. The adipose tissue was treated by the static method (group A), the centrifugal method (group B), and the filtration with different apertures (group C) in the fat treatment device with a closed environment. Each group of granular fat was transplanted to the back of the nude mice, and the grafts were extracted after 1 week, 2 weeks, 4 weeks and 8 weeks. The differences in vascularization and survival rate of the grafts were observed by HE staining, Masson staining, PerilipinA immunofluorescence staining and CD31 immunofluorescence staining. Results In vitro, the volume of adipocytes observed by the static method was the largest, followed by 2.4 mm. In animal experiments, the filtration method had the best retention rate of transplanted fat, and the 1.2 mm group had the highest retention rate. Under the 1.2 mm filtration condition, the size of fat particles can be effectively controlled, fibrous tissues and cell impurities can be removed. At the same time, the concentration and vascularization of Adipose-derived stem cells can be increased, and the fat retention rate can be improved. Conclusion The adipose tissue treated by 1.2 mm pore size filtration has a good fat retention rate and is rich in adipose stem cells, which can be popularized in clinical practice. [ABSTRACT FROM AUTHOR]

The separation efficiency of an air-dense medium fluidized bed is directly affected by coal feed characteristics. So a systematic study had been carried out to investigate the effect of feed-coal particle size and different wash-ability on its separation characteristics. Moreover, the synergy between projectile strength, air volume and different coal feed characteristics on the separation characteristics was evaluated. The results show that the influence of feed-coal particle size on the separation accuracy is rather prominent. Ep values increase with the decrement of particle sizes. The minimum Ep values for 50-25, 25-13 and 13-6 mm difficult-separation coals are 0. 06,0. 07 and 0. 11 g/cm3, respectively. Washability has a slight effect on Ep. The minimum Ep values for easy-separation coal, moderate-separation coal and more difficult-separation coal of 50-25 mm size ranges are 0. 035, 0. 040 and 0. 045 g/cm3, respectively. Separation accuracy is dramatically improved by the optimization of air volume and projectile strength. The optimum operating process parameters of different coal feed characteristics range over which the separator can operate satisfactorily, are found that projectile strength and air volume are 1. 46 and 140 m3/h, respectively. The mechanism of improving fluidized separation by vibration was revealed by analyzing the relationships between initial bubbles frequency and vibration frequency in the vibrated air-dense medium fluidized bed. [ABSTRACT FROM AUTHOR]

Objective To compare and observe the effects of drug-coated balloon (DCB) and drug-eluting stent (DES) in the treatment of de-novo diffuse long coronary lesions. Methods Totally 202 patients with de-novo diffuse long coronary lesions who underwent PCI were divided into the DCB group (68 patients with 72 lesions) and DES group (134 patients with 142 lesions) according to interventional strategy. Patients in the DCB group were treated with DCB only and patients in the DES group were treated with DES only. The differences between the two groups in terms of the immediate postoperative minimum lumen diameter (MLD), stenosis degree and lumen gain were observed. Coronary angiography fol⁃ low-up was performed within 6 to 12 months after PCI. We observed MLD, stenosis degree, late lumen loss, and net lu⁃ men gain at follow-up. The complications of the two groups at 12 months after PCI were also observed, including target le⁃ sion restenosis, target lesion revascularization (TLR), nonfatal myocardial infarction, and all-cause death. Results The immediate postoperative MLD and lumen gain in the DCB group were lower than those in the DES group (all P< 0. 05), and the immediate postoperative stenosis degree was higher in the DCB group (P<0. 05). The late lumen loss at follow-up in the DCB group was lower than in the DES group (P<0. 05). No significant differences were found in the rates of target lesion restenosis, TLR, nonfatal myocardial infarction, and all-cause death between two groups (all P>0. 05). Conclusion The immediate postoperative efficacy of DES was better than that of DCB in the treatment of de-novo diffuse long coronary lesions, but the late lumen loss of DCB was less. [ABSTRACT FROM AUTHOR]

【Objective】This study aimed to investigate the effect of fermentation temperature on the synthesis of ω3/ω6 polyunsaturated fatty acids, PUFAs by M. alpina. 【Method】M. alpina was incubated at six fermentation temperatures( 10, 15, 20, 25, 30, and 35 ℃), and its biomass was measured at the end of fermentation. The composition and contents of fatty acids in hypha were determined by gas chromatography-mass spectrometry( GC-MS) to analyze the effect of fermentation temperature on the synthesis of ω3/ω6 PUFAs by M. alpina. 【Result】The biomass of M. alpina showed a trend of increasing and then decreasing with the increase of fermentation temperature, and the highest biomass( 16.07 g/L) was reached at 25 ℃, and almost no growth at 30 ℃ and above. The components and contents of fatty acids were different under different temperature conditions. Two ω-3 PUFAs including octadecatrienoic acid( α-linolenic acid, ALA) and eicosapentaenoic acid( EPA), and four ω-6 PUFAs including octadecadienoic acid( linoleic acid, LA), octadecatrienoic acid( γ-linolenic acid, GLA), eicosatrienoic acid( DGLA) and eicosapentaenoic acid( arachidonic acid, ARA) were detected in M. alpina hypha. The yields of ω-3 and ω-6 PUFAs were both the highest in hypha at 15 ℃, 51.20 mg/L and 273.13 mg/L, respectively. When the temperature was 30 ℃ and above, the yields of ω-3 and ω-6 PUFAs were suppressed because the fungi hardly grew. 【Conclusion】The fermentation temperature had a significant effect on the biomass and the synthesis of ω-3 and ω-6 PUFAs in M. alpina, and there was a temperature threshold effect, 25 ℃ was the most favorable for the growth of M. alpina, and 15 ℃ was the most favorable for the accumulation of ω-3 and ω-6 PUFAs in hyphae. This study laid the research foundation for the industrial production of ω-3/ω-6 nutritionally balanced dietary oils by M. alpina. [ABSTRACT FROM AUTHOR]

Objective To investigate the difference in naturally occurring resistance-associated variants（RAVs） between the patients with HIV/HCV co-infection and those with HCV infection alone by detecting the drug resistance loci associated with HCV NS3/4 A protease and NS5 A inhibitors. Methods A total of 246 patients with HIV/HCV co-infection or HCV infection alone who were hospitalized or attended the outpatient service in Guangzhou Eighth People’s Hospital, Guangzhou Medical University, from January 2016 to January 2020 were enrolled in this study. Serum samples were collected and next-generation sequencing（Illumina platform, PE250） was used for sequencing. The two groups of patients were compared in terms of RAVs associated with NS3/4 A protease and NS5 A inhibitors approved in China, and the drugs for analysis included asunaprevir/daclatasvir（ASV/DCV） and elbasvir/grazoprevir（EBR/GZR） for HCV genotype 1 b and glecaprevir/pibrentasvir（GLE/PIB） for pan-genotypes. The t-test was used for comparison of normally distributed continuous data between two groups, and the Mann-Whitney U test was used for comparison of non-normally distributed continuous data between two groups; the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. Results Among the 246 serum samples included in this study, 239 samples（97.2%） were successfully amplified by PCR and sequenced, with 102 samples from the patients with HIV/HCV co-infection and 137 from the patients with HCV infection alone. The analysis of RAVs associated with ASV/DCV and EBR/GZR showed that Y56 F, Q80 K/L, and S122 N/R/T associated with ASV and GZR and L31 M and Y93 H associated with DCV and EBR were observed in patients with HIV/HCV（genotype 1 b） co-infection or HCV（genotype 1 b） infection alone; 2 patients with HIV/HCV co-infection had the RAVs of Y56 F+Y93 H associated with EBR/GZR, and 2 with HCV infection alone had the RAVs of Q80 L+L31 M and Y56 F+Y93 H, respectively, associated with EBR/GZR, with no significant difference in RAVs between the two groups（both P>0.05）. The analysis of RAVs associated with GLE/PIB for pan-genotypes showed that 3 patients with PIB-associated Y93 H RAV were observed among the patients with HCV genotype 3 a infection, among whom 2 had HIV/HCV co-infection and 1 had HCV infection alone（P=0.590）, and in addition, no RAVs associated with GLE/PIB were observed. Conclusion There is no significant difference in naturally occurring RAVs associated with HCV NS3/4 A protease and NS5 A inhibitors between the patients with HIV/HCV co-infection and those with HCV infection alone. [ABSTRACT FROM AUTHOR]

BACKGROUND: At present, fusion surgery must be performed to reconstruct the stability of the cervical spine after anterior cervical corpectomy. However, fusion sacrifices the mobility of the surgical segment of the cervical spine. Simultaneously, many articles report the potential long-term problems such as adjacent segment degeneration in fusion surgery. We have done some research and exploration on the preservation of cervical segmental motor function after anterior cervical corpectomy. Combined with three-dimensional printing technology, we have developed “artificial cervical vertebrae-intervertebral disc complex”, referred to as the motion-preserving cervical joint system. OBJECTIVE: To explore the short-term clinical effect of three-dimensional printing motion-preserving cervical joint system implantation in the treatment of two patients with cervical spondylotic myelopathy. METHODS: In view of the loss of motor function of cervical spine segments and the degeneration of adjacent segments after traditional anterior cervical corpectomy operation, in December 2020, a self-developed three-dimensional printing motion-preserving cervical joint system implantation technology was used to treat two patients with cervical spondylotic myelopathy. The patients were followed up for 16 weeks at the time of submission (April 2021). Visual analogue scale score and JOA score were used to evaluate the patient’s pain and neurological recovery at 1, 6, 12, and 16 weeks after the operation. Imaging techniques such as dynamic position X-rays and three-dimensional CT were used to evaluate the position of prosthesis and the preservation of cervical spine motion function. The occurrence of surgery-related complications was observed and recorded during the patient follow-up period. This study was approved by the Ethics Committee of Xi’an International Medical Center Hospital (approval No. 202012). RESULTS AND CONCLUSION: (1) The pain and numbness of the two patients were significantly reduced the next day after the operation, and the muscle strength of the limbs was partially restored. (2) At 1, 6, 12, and 16 weeks postoperative follow-up, the patient’s limb muscle strength, visual analogue scale score, and JOA score were significantly improved compared with preoperatively, and the head and neck movement function was good. During the follow-up, no intra-incision hematoma, recurrent laryngeal nerve injury, esophageal injury, cerebrospinal fluid leakage, incision infection, or screw loosening occurred. (3) At 1, 6, 12, and 16 weeks postoperative follow-up, X-ray examination showed that the cervical spine physiological curvature was well restored, and the intervertebral height was maintained well. 3D-CT showed that the prosthesis components and the cervical spine bones were in good fit. The dynamic position X-ray showed that the prosthesis endplate component had a certain angle of opening and closing changes during flexion, extension and lateral flexion, and there was no cervical spine instability, indicating that the prosthesis retained part of the cervical spine motion function. (4) It is concluded that motion-preserving cervical joint system can retain the function of intervertebral movement on the basis of reconstructing the stability of the cervical spine. [ABSTRACT FROM AUTHOR]

Objectives: The natural evolution process of bank slope is broken by the impoundment of giant reservoir, showing many different development mechanisms and laws of landslide from those before impoundment. One of them is that there is obvious deep-seated toppling failure in a short period of time for the traditionally believed stable anti-dumping bedrock mountain. The scale, mechanism and failure trend of the landslide are the information needed to be grasped for the geological disaster prevention and control in the reservoir area. Methods: After the impoundment of Xiluodu reservoir area in the lower reaches of Jinsha River, the deformation of Yanwan reverse slope occurred. The deformation of the slope was investigated on site twice. The objective is to compare the deformation characteristics of slope before and after impoundment, analyze its deformation mechanism and predict its future deformation and failure trend. Interferometric synthetic aperture radar (InSAR) technology and particle flow code (PFC) method are used. Results: The prediction results show that the failure trend of the slope is the collapse of the shallow rock mass and the widening of the cracks on the upper part of the slope under the action of the structural plane, rather than the overall shear sliding. Conclusions: The deformation of slope is mainly affected by slope structure, insitu stress, lithology and reservoir impoundment. The deformation mechanism can be summarized as follows: After impoundment, the rock mass below the water level produces compression deformation; the deformation response of the upper soft rock mass to the front edge produces toppling deformation and interlayer dislocation; the fractured rock mass compresses the front rock mass under the action of gravity, resulting in the shear creep deformation along the fracture surface. After impoundment, the line of sight deformation rate of the slope gradually increases from the outside to the inside. The PFC simulation results are consistent with the deformation characteristics. The formation lithology in the large deformation area monitored by InSAR is argillaceous limestone and shale interbedding, and its mechanical properties are worse than that of the upper and lower strata, and it is easier to deform, corresponding to the deformation characteristics of InSAR. [ABSTRACT FROM AUTHOR]

The hyporheic zone is a region where surface and subsurface water mix in rivers. It is an important area for the exchange of mass and energy and an essential habitat for aquatic organisms. However, the deposition of colloidal particles in the hyporheic zone can modify the hydrodynamics and ecological environment of the river system. Through recirculating flume experiments and numerical simulations, this paper aims to investigate the transport of colloidal particles between stream and streambed, and clarify the pattern of colloidal particles′ deposition in the hyporheic zone as well as the influence of different factors over particles′ deposition. The results show that the colloidal particles in the overlying water will gradually retain in the streambed and accumulate in the shallow layer. The horizontal distribution of the retained particles tends to be higher on the stoss- side and lower on the lee- side. Hyporheic exchange, settlement of particles and retention of streambed are 3 most important factors in the deposition of colloids in the hyporheic zone. This paper can be helpful for understanding ecological and environmental functions of colloidal particles in hyporheic zone, and it can provide theoretical support for environmental and ecological restoration and health management of rivers. [ABSTRACT FROM AUTHOR]

Objective: To test the validity and reliability of the students rated Chinese version of the Sibling Relationship Questionnaire (SRQ) (Student Version). Methods: Totally 703 students with one sibling from grade 4 to grade 8 in Jilin Province were selected. They completed Chinese version of SRQ, Strengths and Difficult Questionnaire(SDQ) and Egna Minnen av Barndosnauppforstran (EMBU) . Eleven weeks later, 213 participants were retested. Results: The exploratory factor analysis showed that SRQ consisted of 3 factors( Wannth/Closeness, Conflict, and Rivalry), the total variance explained 51. 0% . The confirmatory factor analysis identified that the model fitted well (χ² / df = 1. 89, CFI = 0. 93, TLI = 0. 93, IFI = 0. 94, RMSEA = 0. 05 ). The correlations for Warmth/Closeness, Conflict, and Rivalry were 0. 37, 0. 32, 0. 41, respectively (Ps < 0. 001). The Cronbach a coefficients for the each factor were 0. 95, 0. 87 and 0. 84, respectively, the test-retest reliabilities for the 4 factors were 0. 62, 0. 64 and 0. 45, respectively. Conclusion: The Chinese version of the Sibling Relationship Questionnaire (StudentsVersion)has satisfactory validity and reliability, which could be used to measure the quality of sibling relationship in the context of Chinese culture. [ABSTRACT FROM AUTHOR]

Objective: To investigate anxiety, depression and suicidal ideation in personnel returning from overseas during the COVID-19 epidemic in quarantined hotel. Methods: An online survey on returnee Chinese who were quarantined in hotels from March 20th to May 24th 2020 was conducted. Self-rating Anxiety Scale (SAS, with an index of 60 or above being indicative of moderate to severe anxiety), Self-rating Depressive Scale ( SDS, wi1h an index of 0. 60 or above being indicative of moderate to severe depression) and Self-compiled Suicide Screening Questionnaire ( SSSQ) were used to assess symptoms of anxiety, depression and suicidal ideation. And logistic regression was adopted to find out 1he risk factors. Results: Forty-three ( 1.6%) reported moderate to severe anxiety symptoms, 169 (5. 4%) reported moderate to severe depressive symptoms and 34 ( 1.1 % ) reported suicidal ideation. Females were more likely to suffer moderate to severe anxiety (OR = 2. 61, P < 0. 01 ). Those who had a history of psychiatric care or counseling were susceptible to moderate to severe anxiety or depression (OR= 8. 56, 4. 22 ; P <0. 001). Students were less likely to suffer moderate to severe anxiety or depression (OR= 0.41, 0.45, Ps < 0.05). The risk of suicidal ideation increased with the severity of depression (OR = 9.11, 37.42, 288.12; Ps < 0.01). Conclusion: A few of returnee Chinese who are quarantined in the hotels during the COVID-19 epidemic show moderate to severe anxiety, depression and suicidal ideation, and being female, not studying aboard and having a history of psychiatric care or counseling may be risk factor. [ABSTRACT FROM AUTHOR]

Yunnan Dulong Sn-Zn pofymetallic deposits has large reserves of major metals such as Sn and Zn，and the reserves of associated scattered elements such as In and Cd in the deposits are also considerable. Based on the three-dimensional spatial positioning of samples the cluster analysis and spatial zoning of 570 groups of main and trace elements analysis data formed by mining exploration were studied. Cluster analysis results show that Ag-Cu-As is clustered into one group，which is the low and medium temperature element association near the ore；Zn-Cd-S-In-Sn is clustered into group of pofymetallic sulphide ore elements，and Ga and Ge have poor correlation with other elements. Composite mapping of the zoning indices of Sn，Zn，Cd，Ga，Ge and In elements in the dip-vertical and strike-vertical directions was carried out. The results show that the Zn has a high composite zoning index in the ore body and above，and the Sn has a high composite zoning index in the ore body and below. The two-element mineralization has both the characteristics of layer distribution and the characteristics of vertical layering，which is supposed to be the result of superposition of multi-stage mineralization. The spatial enrichment law of Cd is consistent with that of Zn，it is speculated that Cd mainly occurs in the lattice of marmatite. The enrichment of Ga is closely related to the spatial position of the granite. Ge and In enrichment layers are stable and have a high degree of coincidence with the main orebody it is speculated that Ge and In are mineralized together with pofymetallic sulfides. [ABSTRACT FROM AUTHOR]

The cracks in 50SiMnVB steel are experimentally controlled by using high power CO2 laser to improve the processing efficiency and subsequent processing of fracture splitting groove. The laser deeper melting zone of micro-structure, fracture morphology and micro-hardness distribution are analyzed by means of metallographic microscope, scanning electron microscope and micro-hardness tester, respectively. The numerical simulation software SYSWELD is used to simulate the distributions of temperature field and stress field in 50SiMnVB steel during laser deeper melting. The results show that the hardened brittle cracks are generated in the deeper melting zone due to temperature and stress gradient. The cracking mechanism is that the pores and micro-cracks arise at the bottom of the deeper melting zone, and the cracks expand along the center to form the macroscopic cracks. The optimal range of processing parameters is obtained by the experiment and simulation with laser power of 3.0 kW, and scanning speed of 1.0- 4.5 m/min. The corresponding depth range of prefabricated crack is about 3-7 mm. [ABSTRACT FROM AUTHOR]

The current digital camouflage is not able to withstand the future high-tech reconnaissance and monitoring due to its planarity and inalterability. To address the issue， a 3D dynamic imaging algorithm based on lenticular raster is proposed. The proposed algorithm fully takes the biological characteristics of human binocular stereo imaging and the optical characteristics of splitting light and imaging of lenticular raster into account to describe the feasibility of 3D dynamic digital camouflage. On this basis, the parallax design principle of 3D dynamic imaging for digital camouflage is deduced, and the multiple sequence diagrams are generated according to depth information of background. The comb function is used to sample and synthesize the sequence diagrams. The resultant raster image could be mounted on the back of a grating plate to achieve 3D dynamic imaging. The simulation results show that the proposed algorithm can be used for the 3D dynamic imaging of digital camouflage. [ABSTRACT FROM AUTHOR]