OBJECTIVEThe cochlear nucleus (CN) neurons show 3 principal response patterns to short tone bursts, namely the primary-like, chopper and onset response patterns. We previously established an excitatory model to simulate the response patterns of CN neurons to stimuli. In this study, we aimed to investigate the effects of excitatory intensity on the CN neuron response patterns and explore the role of inhibitory inputs under normal physiological conditions.

METHODSBased on the platform of Matlab and the excitatory model derived from the integrate-and-fire model, we altered the intensity of excitatory inputs in dB range and obtained the histograms to analyze the changes in the response patterns of the neurons using OriginPro 7.5 data analysis software.

RESULTSThe original primary-like response pattern of the neurons did not vary significantly while the chopper and onset response patterns changed into primary-like responses with the increase of the excitatory input intensity. But this response pattern alteration as a result of excitatory input intensity changes was rarely observed under normal physiological conditions.

CONCLUSIONSThe CN neurons receive balanced excitatory and inhibitory inputs, which stabilize the neuronal membrane potential within a limited range. The balanced inhibitory inputs decide the response pattern of a given neuron.

This article was aimed to study the preparation process of glycyrrhetinic acid (GA)-tanshinone IIA (TSN)-salvianolic acid B (SalB) compound liposomes with 3-succinic-30-stearyl glycyrrhetinic acid (18-GA-Suc) which is one of amphiphilicglycyrrhetinic acid derivatives as targeting molecule. The structure of the targeting molecule was validated by 1H-NMR and 13C-NMR methods. The feed ratio of 18-GA-Suc was optimized through single factor test and the incorporation ratio of 18-GA-Suc was determined by low-speed centrifugation. Meanwhile, physicochemi-cal properties between Suc-GTS-Lip and GTS-Lip were compared. In vitro release studies of three components in Suc-GTS-Lip were conducted by equilibrium dialysis method. The results showed that the optimum conditions were when the feed ratio of 18-GA-Suc was 10%lipid liposomal membrane (mol·mol-1). It revealed that the incorpora-tion ratio of 18-GA-Suc was 96.58%, and the encapsulation efficiencies of GA, TSN, and SalB were about 86.15%, 81.70%, and 91.05%, respectively. In addition, the Suc-GTS-Lip was spherical and uniformly dispersed with parti-cle size of 128.7 nm and zeta potential of-15.5 mV. The release model of GA and TSN was fitted well with Higuchi equation, while SalB was fitted well with Hixon-crowell equation. It was concluded that Glycyrrhetinic acid deriva-tives (18-GA-Suc) can be successfully expressed in the liposome membrane, and the optimal preparation method of Suc-GTS-Lip was stable. All three components encapsulated into liposomes had sustained-release effects, which laid a good foundation for its further study about liver-targeting.

Objective To evaluate the diagnostic performance of diffusion kurtosis imaging (DKI) and its combination with DWI and proton MR spectroscopy (1H-MRS) in differentiating malignancy from benign breast lesions. Methods Fifty-three patients with 38 histopathologically confirmed malignant and 15 benign breast lesions were retrospectively studied. The patients were examined by breast MRI at 3.0 T prior to operation, including conventional T1WI, fat-suppression imaging, DWI, DKI and 1H-MRS. The shape and margin of breast lesions, and their corresponding mean values for ADC, mean kurtosis (MK) and mean diffusivity (MD) were determined by two blinded radiologists in consensus. The presence or absence of choline (Cho) peak was identified using LCModel software. Independent-samples t test or χ2 test was performed for the comparison of clinical characteristics, shape and margin of lesions, and imaging parameters between malignancy and benign lesions. ROC analysis was performed to evaluate the diagnostic accuracy of DKI, DWI and 1H-MRS alone or in combination, in comparison with the histopathologic findings. Results The onset age of breast malignancy was higher than that of benign ones, and the difference has statistical significant (P<0.05). Malignant lesions were most often seen in postmenopausal women, with unclear margin. There was no significant differences for body mass index (BMI), fiber type, the size and shape of lesions between benign lesions and malignancy (P>0.05). The mean ADC,MD and MK of benign lesions were(1.464 ± 0.348)× 10-3mm2/s,(1.726 ± 0.268)× 10-3mm2/s and(0.692 ± 0.227), the mean ADC,MD and MK of malignancy were(0.963 ± 0.170)× 10-3mm2/s,(1.158 ± 0.262)× 10-3mm2/s and(1.311 ± 0.218), respectively. Significant differences were obtained between benign and malignant lesions for all parameters (P<0.05).The area under the ROC curve (AUC) of ADC, MD and MK for differentiating malignancy from benign lesions was 0.913, 0.933 and 0.968, respectively. Taken the maximum Youden's index of MK (1.110) as the ROC optimal cut-off point, MK exhibited better diagnostic sensitivity, specificity and accuracy for distinguishing malignancy from benign lesions [89.5%(34/38),93.3%(14/15) and 90.6%(48/53), respectively], compared with MD and ADC. Multiparametric imaging with combination of DKI, DWI and 1H-MRS improves the diagnostic specificity (with the highest as 100.0%) but decreases the sensitivity (with the highest as 81.6% and lowest as 71.1% ), compare with the single parametric imaging. Conclusions MK generated from DKI enables differentiation of breast lesions with a higher diagnostic sensitivity and specificity than DWI and 1H-MRS. DKI combined with DWI and 1H-MRS increase specificity but decrease sensitivity for breast cancer characterization.

AIM To study the influence of Huangqi Powder (Puerariae lobatae Radix,Astragali Radix,Mori Cortex) on femur and tibia in rats with glucocorticoid-induced osteoporosis (GIOP).METHODS Thirty one-month-old male SD rats were divided into three groups by randomized block design,which were control group (normal saline),prednisone group (3.5 mg/kg prednisone acetate),Huangqi Powder group (clinical adult dosage).Experimental test was maintained for one hundred and twenty days.Double fluorochrome labeling with calcein was performed before necropsy;bone resorption and bone formation index were determined by using blood serum;the femur structural and material mechanics were analyzed by using bone biomechanics method.The cancellous bone of proximal tibial and the cortical bone of tibial shaft static parameter and dynamic parameter were analyzed by bone histomorphometry method.RESULTS Huangqi Powder had no obvious improving effects on bone biomechanics and bone static parameter,but could increas the area,width and number of the proximal tibia bone trabecular.Mark perimeter percentage and mineralization rate of deposition could be increased.CONCLUSION Huangqi Powder can significantly increase proximal tibia cancellous bone mass and enhance bone trabecula structure of glucocorticoid-induced osteoporosis rats.

Objective To analyze the biophysical dosimetric characteristics and clinical application ability of VMAT technology for breast cancer post-mastectomy.Methods 28 patients with breast cancer (10 at left side and the other at right side) were planned in different ways respectively.One was two 90 degree arc VMAT plan and the other were 5 beam IMRT plan.The dosimetric parameters of two different plans including tumor control probability (TCP),conformity index(CI),homogeneity index (HI),V95and V110 in target,normal tissue complication probability (NTCP),V5,V20,V30 for ipsilateral lung,NCTP,D V25 for heart,D for the contralateral breast in OARs,MU and times were compared.Results The average tumor control probability (TCP) in VMAT and IMRT group was(96 ±2)％ and (90 ±2)％ (t =-6.28,P ＜ 0.01),respectively.The PTV dose average homogeneity index (HI) of VMAT plans was better than that of IMRT plan (0.15 ±0.04 vs 0.22 ±0.02,t =13.29,P ＜0.01).For cancer position in left side,the mean dose of heart was decreased by 433.24 cGy in the VMAT plan.The NTCP of the hearts in VMAT plans had statistically significant difference compared with IMRT plans [(1.00±0.12)％ vs (1.70±0.13)％,t =2.14,P ＜0.05].For plans of right breast cancer,the average mean dose of hearts in two control group was (3.27 ± 0.26) Gy and (6.00 ± 0.47) Gy (t =9.21,P＜0.01).The total monitor unit (MU) was 530.7 in the VMAT arm and 693.9 in the IMRT arm (t =9.58,P ＜0.01).The treatment time was shorter in VMAT arm (t =8.40,P ＜0.05).Conclusions VMAT plans have better clinical value and more superior biophysical dosimetric characteristics for breast cancer post-mastectomy.

Objective To compare the dosimetric results of postoperative intensity modulated radiation therapy (IMRT) using single-energy or mixed-energy photons in invasive thymoma patients.Methods Simulation CT images were acquired and clinical target volume (CTV),planning target volume (PTV) and organs at risk (OARs) were defined.Three sets of fixed-field IMRT planning were generated using 6 MV,10 MV and mixed 6/10 MV photons for each case.Monitor Units (MUs) for each plan were recorded after optimization,and parameters of PTV such as conformity index (CI),homogeneity index (HI) and dose to OARs were evaluated on dose-volume histograms.Results Near-Maximal dose (D2％) received by PTV was better in mixed-energy IMRT as compared with 6 MV(t =3.107,P ＜0.05).HI was better in mixed-energy than in 6 MV(t =2.924,P ＜0.05).There were statistically significant differences in CI among three IMRT plans.MU was higher in 6 MV than in both 10 MV and mixed-energy IMRT.The percentages of lung volumes receiving 5 Gy (V5),10 Gy(V10),20 Gy (V20),30 Gy (V30) and the mean lung dose (D) were also significantly different in most plans.V30 and V40 of the heart were comparable between 6 MV and mixed energy plans but better than in 10 MV plan.Conclusions If the reasonable choice of beam angles and number,and capability of energy selection according to beam directions,with combined advantages of low and high energy photons,mixed IMRT plans can improve the quality of IMRT plans in general and has clinical potential for postoperative radiotherapy of invasive thymomas.

Objective: To evaluate the effect of slow release microcapsules of bFGF on implanted vein graft. Methods: The vein graft stenosis model was made in 24 New Zealand rabbits. Group I (n=8) served as control group, group II (n=8) as blank microcapsule group, group III(n=8) ,each microcapsule contains 1?g bFGF as bFGF group. In group II and III,5 blank microcapsules or bFGF slow release microcapsules were implanted close to the vein graft respectively. Animals were sacrificed 5 weeks later for assessment of reendothelialization, neointimal thickening and for analysis of in vitro vasoreactivity. Results: As compared with group I and II,rabbits treated with bFGF showed remarkbale degree of reendothelialization [group I (4.08?1.61)mm 2, group II (3 93?1 54) mm 2 vs. group III (12.93?2.030 mm 2, P

Objective: In order to provide guidance for the prevention and control of epidemic situations in schools, this paper explores the risk perception and prevention behaviors of college students after classes resume in the post-epidemic period of novel coronavirus pneumonia. Methods: By using convenient sampling method, 835 college students who resumed classes were randomly selected from a university in Guizhou. Self-efficacy questionnaire, perceived social support questionnaire and self-designed questionnaire were adiministered. Results: Totally 37.0% of college students believed that the risk of infection was high, 57.4% of college students believed the severity of infection was very high once get infected, meanwhile, 84.3% of them think that keeping away from crowded places was a better preventive behavior, 89.7% of college students often wear masks, 91.4% of college students wash their hands frequently. There was a significant positive correlation between general self-efficacy, perceived social support and preventive behavior (r=0.10-0.65, P<0.01). General self-efficacy and perceived social support play both a partial intermediary role and a chain intermediary role between risk perception and preventive behavior. Conclusion Risk perception of Novel Coronavirus was moderate among college students, who can take active measures to effectively prevent it. Risk perception could not only directly affect the prevention behavior of college students, but also indirectly affect the prevention behavior of college students through understanding social support and general self-efficacy.

Objective To investigate the time course and prognosis of perioperative deep venous thrombosis in hip fracture patients.Methods A prospective study was conducted to analyze the clinical data of 88 patients with hip fractures who were injured within 24 h in the Department of Traumatic Orthopedics,Honghui Hospital,Xi'an Jiaotong University from September 2017 to March 2018.The patients were divided into anticoagulant group (n =53) (low molecular weight heparin combined with physical prevention) and non-anticoagulant group (n =35) (physical prevention only).The patients were examined by deep venous examination of the lower limbs every 24 h after they were admitted to hospital.The number and incidence of new thrombosis within 4 d after injury and 7 d after operation were recorded.The histogram was recorded.The prognosis of thrombosis and the occurrence of thrombosis in different fracture sites were also recorded.Counting data were expressed by percentage (％),and x2 test was used for comparison between groups.Results In the anticoagulant group,33 cases of deep venous thrombosis occurred in 53 cases,and the incidence rate was 62.26％.Deep venous thrombosis occurred in 29 of 35 patients in non-anticoagulant group (82.86％).The difference between the two groups was statistically significant (P ＜ 0.05).In anticoagulant group,thrombosis occurred in 10 cases (18.87％),7 cases (13.21 ％),1 case (1.89％),5 cases (9.43％),7 cases (13.21％) and 3 cases (5.66％) on the 1st,2nd,3rd and 4th day after injury.In non-anticoagulant group,thrombosis occurred in 7 cases (20.0％),8 cases (22.86％),2 cases (5.71％),1 case (2.86％),4 cases (11.42％),3 cases (8.57％),1 case (2.86％),1 case (2.86％),1 case (2.86％),1 case (2.86％) and 1 case (2.86％) respectively on the 1st,2nd,3rd,4th and 6th days after operation.Of the 62 thrombus cases,22 (35.48％) were changed from unilateral to bilateral,6 (9.68％) disappeared,3 (4.84％) from distal to proximal (1 case of pulmonary embolism),1 (1.61％) from proximal to distal,and 30 (48.38％) remained unchanged.43 cases of femoral neck fracture,27 cases of deep vein thrombosis,the incidence rate was 62.79％,45 cases of intertrochanteric fracture,35 cases of deep vein thrombosis,the incidence rate was 77.78％.There was no significant difference between the two groups (P ＞ 0.05).Conclusions Despite routine prophylactic anticoagulation therapy,the incidence of deep venous thrombosis is still high in hip fracture patients.The peak time of perioperative deep venous thrombosis in hip fracture patients was 2 d after injury and 2 d after operation.There was no significant change in thrombus after conventional anticoagulation therapy in patients with deep venous thrombosis during perioperative period,and even some of the thrombus changed from unilateral to bilateral.

Objective To study the geometric difference between six different ITV generation methods from 4DCT for patients with non?small cell lung cancer ( NSCLC) treated with stereotactic ablative radiotherapy technique ( SABR) . Methods Between Dec. 2013 and Mar. 2014,16 patients were enrolled in this retrospective study. All patients underwent imaging with 4DCT scans. The MI and DI index were evaluated between six ITV generation methods:combining GTV from all 10 respiratory phases ( ITV10 );combining GTV from four respiratory phases, including two extreme phases ( 0% and 50%) plus two intermediate phases ( 20% and 70%) ( ITVYeo ) which was proposed by Seung?Gu Yeo of Soonchunhyang University;combining GTV from two extreme phases ( ITVEI+EE ) . And combining GTV from five odd phases (10%,30%,50%,70%,90%)(ITVodd).Accordingly the ITVEVEN which was combined from the remaining five even phases (20%,40%,60%,80%,0%),and ITVAVG,ITVMIP were contoured from two reconstructed 4DCT sequences,finally,a method which was not sensitive to the tumor volume and motion characteristic was selected for clinical use. Data were compared using a variance analysis followed by Student?Newman?Keulsa test both in same group or between groups. At the same time, the volume and the three dimensional movements of the tumor, the relativity of MI and DI were analyzed by Multi?parameter regression analysis. Results The mean (range) tumor motion (RLR,RAP,RCC,and R3D) are 3. 5 mm (1. 4?8. 4 mm),4. 5 mm (1. 1?8. 6 mm),9. 5 mm (0?10 mm),12. 3 mm (2. 5?55. 3 mm) respectively. The IGTVx volume are Underestimated by 25. 7%,35. 6%,17. 9%,12. 8%,3. 6%,4. 8%( P=0. 000) respectively. The MI index comparisons between six ITV generation methods and ITV10 showed statistical significance:0. 69,0. 62,0. 80, 0. 86,0. 93,0. 91 ( P=0. 006 ) . The DI index showed no statistical significance:0. 98, 0. 98, 0. 97, 0. 97, 0. 99,0. 98(P=0. 130).The tumor size and motion amplitude were certified not the independent factors for the MI index of ITVodd and ITVEVEN . Conclusions IGTVODD/EVEN based on odd or even 4DCT phases is not sensitive to the tumor size or motion characteristic and is proved to have a good marching with ITV10 meanwhile maintaining a reasonable contouring efficiency,it can be recommend to the institutions which was not equipped with the deformable registration systems.