BACKGROUND:Three-point mechanics is an effective method for ankle foot orthosis correction and prevention of various foot diseases.At present,the clinical application research on 3D printing ankle foot orthosis has been widespread;however,there are relatively few reports on numerical simulation and finite element analysis involving three-point mechanical correction.There is a lack of relevant biomechanical experimental verification. OBJECTIVE:Three-point force was loaded to analyze the composite model of ankle foot orthosis and foot by finite element method,observing the effect of foot correction with ankle foot orthosis under three-point force intervention,verifying the effectiveness of three-point force and the reliability of ankle foot orthosis. METHODS:A three-dimensional foot and ankle model of a healthy volunteer was constructed based on the medical image processing software Mimics.Rodin 4D and Geomagic reverse engineering software were used to optimize the models and design personalized ankle foot orthosis models.Solidworks software was utilized to turn the ankle model inside for 10° to simulate the foot varus disease.Static loading was carried out on the foot force application area by ANSYS software combined with the three-point mechanics principle.The deformation and stress changes of the foot and ankle tissues were analyzed when the human foot pain threshold was met.The display dynamics was used to further verify the effectiveness of the three-point force applied by the ankle foot orthosis. RESULTS AND CONCLUSION:(1)The personalized ankle foot orthosis designed in this paper had the effect of preventing and fixing foot and ankle varus.The ankle varus was 1.81 mm after being loaded with 1 N·m of varus when not wearing ankle foot orthosis,while it was only 0.44 mm after wearing ankle foot orthosis,the deformation rate was reduced by 75.7%,and the effect of preventing varus was significantly enhanced.(2)When only coronal correction was performed,the low calcaneal force would aggravate the varus angle of the front foot.After adjusting the correction force on the inside of the heel and above the medial malleolus,the varus angle of the front foot and the calcaneus position were improved;however,the medial phalangeal region of the foot still had different degrees of adduction and displacement,which would aggravate the adduction deformity of the patient's front foot.(3)The correction effect of the coronal plane and horizontal plane was better than that of the single coronal plane.There was no adduction and displacement of the medial phalanges of the front foot and the varus angle of the front foot decreased under the force(25,10,10,20 N)of the medial heel,the medial shaft of the first metatarsal,below the lateral malleolus and above the medial malleolus,and the valgus along the X-axis was corrected by 1.395 mm,the calcaneus valgus was corrected by 1.227 mm.The calcaneus varus angle was corrected from 10.21° to 7.25°,and the varus angle was improved by 28.9%.(4)The lateral plantar metatarsal load decreased,the medial plantar metatarsal load increased under the action of a two-plane three-point force,and the plantar bone stress was significantly improved after correction.Thus,the reliability of the three-point force principle was further verified.This study provides an important theoretical support for the implementation of ankle foot orthosis in the treatment of varus in clinical practice.

The setting and adjustment of ventilator parameters need to rely on a large amount of clinical data and rich experience. This paper explored the problem of difficult decision-making of ventilator parameters due to the time-varying and sudden changes of clinical patient's state, and proposed an expert knowledge-based strategies for ventilator parameter setting and stepless adaptive adjustment based on fuzzy control rule and neural network. Based on the method and the real-time physiological state of clinical patients, we generated a mechanical ventilation decision-making solution set with continuity and smoothness, and automatically provided explicit parameter adjustment suggestions to medical personnel. This method can solve the problems of low control precision and poor dynamic quality of the ventilator's stepwise adjustment, handle multi-input control decision problems more rationally, and improve ventilation comfort for patients.
Humans ; Ventilators, Mechanical ; Respiration, Artificial ; Neural Networks, Computer

Objective:To discuss the effect of fingertip reconstruction with V-Y advancement flap and nailbed suture treating Allen’s type Ⅲ amputations unsuitable for vascular anastomosis.Methods:From September 2018 to December 2020, clinical data of patients with Allen’s type Ⅲ fingertip amputations treated in Northern Jiangsu People’s Hospital were analyzed retrospectively. The fingertips were reconstructed with V-Y advancement flap and nailbed suture. The infeasibility of vascular anastomosis was checked under the microscope. Following fixation of the distal phalanx, the nailbed was stretched as flat as possible and sutured. If the nail plate was missing, a manual nail plate made from a plastic transfusion pipe would be fixed to cover the exposed nailbed. The palmar soft tissue of the amputated fingertip was excised, and periosteum, hyponychium, nailbed, and dorsal soft tissue were retained. The proximal volar skin was incised until the subcutaneous adipose layer to get a V-Y advancement flap. The volar defect was repaired with the V-Y advancement flap distally sutured with the pre-retained hyponychium. Postoperatively, burn cream was smeared on the nail for moisturizing, without lamp heating, and intravenous antibiotics was administered routinely. The main indexes were collected including nail appearance, pulp plumpness, static two-point discrimination, motion loss of the distal interphalangeal joint, and patients’ self-evaluation of the appearance. Chinese Medical Association trial standard of upper limb partial function assessment (CMA evaluation) was used to evaluate finger function.Results:A total of 16 patients with 18 fingertips were included. There were 9 males and 7 females, aged (31.5±6.1) years (21-52 years). There were 14 cases of single fingertips injury and 2 cases of multiple fingertips injury. Damaged finger: 2 of thumb, 3 of indicator finger, 6 of middle finger, 5 of ring finger, 2 of little finger. All 18 fingertips survived postoperatively and followed up for 7-16 months (median 12 months). One case underwent a second surgery due to infection and mild bone exposure followed by good healing. One case had a slightly hooked nail. The fingertip appearance was satisfying or acceptable by all the patients except the above two. Good results were got for all patients such as bone healing, smooth nail, plump pulp, and flexible distal interphalangeal joint. At the latest follow-up, motion loss of the distal interphalangeal joint was 0°-3.6° (mean 2.4°) for extension and 2.0°-12.0° (mean 7.6°) for flexion. The static two-point discrimination was 2.5-4.6 mm (mean 3.8 mm). Respectively, the functional evaluation of the affected finger was excellent in 11 cases, good in 3 cases and fair in 2 cases according to the CMA evaluation.Conclusion:Fingertip reconstruction with V-Y advancement flap and nailbed suture is a good technique to treat Allen’s type Ⅲ amputations, with advantages of preserved fingertip length, smooth nail, plump pulp, good sensory and flexible distal interphalangeal joint. The technique is simple with a high success rate and good results.

Objective:To discuss the effect of fingertip reconstruction with V-Y advancement flap and nailbed suture treating Allen’s type Ⅲ amputations unsuitable for vascular anastomosis.Methods:From September 2018 to December 2020, clinical data of patients with Allen’s type Ⅲ fingertip amputations treated in Northern Jiangsu People’s Hospital were analyzed retrospectively. The fingertips were reconstructed with V-Y advancement flap and nailbed suture. The infeasibility of vascular anastomosis was checked under the microscope. Following fixation of the distal phalanx, the nailbed was stretched as flat as possible and sutured. If the nail plate was missing, a manual nail plate made from a plastic transfusion pipe would be fixed to cover the exposed nailbed. The palmar soft tissue of the amputated fingertip was excised, and periosteum, hyponychium, nailbed, and dorsal soft tissue were retained. The proximal volar skin was incised until the subcutaneous adipose layer to get a V-Y advancement flap. The volar defect was repaired with the V-Y advancement flap distally sutured with the pre-retained hyponychium. Postoperatively, burn cream was smeared on the nail for moisturizing, without lamp heating, and intravenous antibiotics was administered routinely. The main indexes were collected including nail appearance, pulp plumpness, static two-point discrimination, motion loss of the distal interphalangeal joint, and patients’ self-evaluation of the appearance. Chinese Medical Association trial standard of upper limb partial function assessment (CMA evaluation) was used to evaluate finger function.Results:A total of 16 patients with 18 fingertips were included. There were 9 males and 7 females, aged (31.5±6.1) years (21-52 years). There were 14 cases of single fingertips injury and 2 cases of multiple fingertips injury. Damaged finger: 2 of thumb, 3 of indicator finger, 6 of middle finger, 5 of ring finger, 2 of little finger. All 18 fingertips survived postoperatively and followed up for 7-16 months (median 12 months). One case underwent a second surgery due to infection and mild bone exposure followed by good healing. One case had a slightly hooked nail. The fingertip appearance was satisfying or acceptable by all the patients except the above two. Good results were got for all patients such as bone healing, smooth nail, plump pulp, and flexible distal interphalangeal joint. At the latest follow-up, motion loss of the distal interphalangeal joint was 0°-3.6° (mean 2.4°) for extension and 2.0°-12.0° (mean 7.6°) for flexion. The static two-point discrimination was 2.5-4.6 mm (mean 3.8 mm). Respectively, the functional evaluation of the affected finger was excellent in 11 cases, good in 3 cases and fair in 2 cases according to the CMA evaluation.Conclusion:Fingertip reconstruction with V-Y advancement flap and nailbed suture is a good technique to treat Allen’s type Ⅲ amputations, with advantages of preserved fingertip length, smooth nail, plump pulp, good sensory and flexible distal interphalangeal joint. The technique is simple with a high success rate and good results.

Objective:To describe the distribution of volumetric breast density(VBD) in different ages of Chinese women based on X-ray mammograms.Methods:Based on mammographic images of 1 140 patients from January 2010 to December 2016 in a hospital in Beijing, the VBD of women was assessed by Volpara 1.5.1 and graded according to breast imaging reporting and data system published by American College of Radiology. The patients were divided into two groups according to the median age, and the two independent samples t-test was used to compare them. The patients were also divided into four groups according to age ( <40 years, 40-49 years, 50-59 years, ≥ 60 years), and the breast thickness, breast volume, glandular volume, and VBD were compared using a One-way ANOVA analysis. Results:The median age was 50 years. The compressed breast thickness and breast volume in patients over 50 years were significantly higher than those in patients below 50 years ( t= -8.99, -7.92, P<0.001), while glandular volume and VBD were significantly lower than those below 50 years ( t= 8.11, 18.49, P<0.001). The compressed breast thickness, breast volume, glandular volume, and VBD were statistically significant different among four groups ( F=27.10, 22.34, 25.70, 122.03, P<0.001). Patients over 60 years had the lowest VBD ( t=-12.56, -15.27, -4.57, P<0.001). VBD was negatively correlated with ages ( r=0.47, P<0.001). Conclusions:The compressed breast thickness and breast volume increased with ages, while the glandular volume and VBD decreased with ages.

Objective:To investigate the feasibility of the application of low tube potential scanning in dacryocystography CT.Methods:The mixture of iohexol and saline with the ration of 1∶3 as the dacryocyst was set on the nose wing of the head-neck phantom. The phantom was scanned at 80, 100, 120, 140 kV with appropriate mAs to set the volume CT dose index(CTDI vol)at 10, 15, 20, 25, 30, 35 or 40 mGy. All the images were objectively evaluated to find out the optimal scanning parameters of 80 kV/240 mAs with the same contrast-to-noise ratio(CNR)of conventional scanning condition of 120 kV/180 mAs. A total of 62 patients who conducted dacryocystography CT in Beijing Tongren Hospital from November 2019 to July 2020 were prospectively selected. They were randomly divided equally into conventional scanning group with 120 kV/180 mAs and low tube potential group with 80 kV/240 mAs. The CT number, noise (SD) and contrast-to-noise ratio (CNR) of the two groups were measured as the objective evaluation indicators of image quality. The subjective evaluation was performed by two senior radiologists using a double-blind method and a 5-scale system evaluation. Results:For the phantom study, the CNR was positively correlated with CTDI vol under the same tube potential ( r=0.985, 0.965, 0.971, 0.972, P < 0.05). With the same CNR, the radiation dose decreased with lower tube potential. Under the conventional scanning parameters of 120 kV/180 mAs, the CNR was 27.8. At the same CNR, the optimal scanning parameters were 80 kV/240 mAs. For the clinical study, the CTDI vol of conventional scanning group and low tube potential group were 31.2 and 12.8 mGy respectively, 59% decreased in low tube potential group. There were statistically significant differences in CT number of dacryocyst area, CT number of orbital fat area and noise between the two groups ( t=-3.476, 2.601, -5.704, P < 0.05). There was no statistically significante difference in CNR between 2 groups( P>0.05). Two observers had a good consistency ( Kappa >0.75). There was no statistically significante difference in subjective rating between 2 groups( P>0.05). Conclusions:Low tube potential scanning could obtain satisfactory image quality in dacryocystography CT at much lower radiation dose.

Objective:To investigate the effect of organ dose modulation (ODM) technique on reducing the breast radiation dose in chest CT scanning.Methods:In the phantom test, the PBU-2 adult chest module was used. The clinical chest scan protocol was used and three sets of scans performed on the chest module： (1) ODM off group, ODM was not used; (2) ODM part group, ODM was applied only in the breast region； (3) ODM all group, ODM was applied in the whole scan scope. Other scan parameters were same for the three groups, with smart mA applied. The volume CT dose index (CTDI vol) was recorded for all three groups. A long rod ionization chamber was placed in a fixed position in front of the right breast area to measure the breast skin dose (D). The contrast noise ratio (CNR) and the figure of merit (FOM) were measured respectively. In clinical research, 72 female patients who underwent chest CT scanning in Beijing Tongren Hospital Capital Medical University from August to November 2018 were retrospectively recruited. According to the application of ODM, the patients were divided into ODM off group (without ODM, 36 cases) and ODM part group (ODM applied in the breast region, 36 cases). The CTDI vol and the dose length product (DLP) were recorded. CNR, noise of images were measured and calculated, respectively. The image quality was evaluated by subjective evaluation scores. The one way ANOVA analysis was used in comparing the difference of CNR among the 3 groups in module test. As for clinical cases, the independent samples t test was used to compare the difference in CTDI vol, DLP, CNR and the noise between two groups; and the rank-sum test was used for comparison in image quality subjective evaluation. Results:In module test, the radiation dose was highest in ODM off group, and lowest in ODM all group. The CTDI vol were (6.90±0.02), (6.26±0.02) and (5.99±0.02) mGy, and the D values were (9.17±1.01), (8.01±0.92) and (7.58±0.87) mGy for ODM off group, ODM part group and ODM all group respectively. The CNR values of images with soft tissue algorithm reconstruction were highest in ODM off group and lowest in ODM all group, while no statistically significant difference was displayed ( P>0.05). The CNR values of the images with lung algorithm reconstruction showed the same trend, with statistically significant difference among the three groups ( F=154.732, P=0.006). The FOM of the lung and soft tissue algorithm images was maximized when the ODM was partially applied. As for clinical cases, compared with ODM off group, the dose of ODM part group showed significantly decreased, with CTDI vol decreased by 16.12% ( t=2.604, P=0.011), and the DLP decreased by 16.85% ( t=3.293, P=0.002). No significant difference was found in CNR, noise and subjective score by two doctors between two groups ( P>0.05). Conclusion:The application of ODM in chest CT imaging can reduce the radiation dose of breast with simultaneously maintaining the image quality.

Objective:To evaluate correlation between left ventricular mechanical contraction synchrony and left ventricular systolic function by gated myocardial perfusion imaging(GMPI) using Cadmium-Zine-Telluride (CZT) SPECT.Methods:Three hundred and forty three consecutive patients( 232 males, 111 females, age (60.08±12.88) years) who underwent CZT SPECT GMPI in Shanxi Cardiovascular Hospital between January and August 2019 were retrospectively analyzed. The Emory cardiac toolbox was used to process the imaging data, and the left ventricular systolic synchrony parameters and systolic function parameters were acquired, including peak phase(PP), phase standard deviation (PSD), phase histogram bandwidth(PHB), histogram skewness(HS), histogram kurtosis(HK), and end-diastolic volume( EDV), end-systolic volume (ESV), left ventrieular ejection fraction (LVEF). All patients were divided into 4 groups: the normal group (147 cases), ischemic cardiomyopathy group (114 cases), nonischemic cardiomyopathy without left bundle branch block (LBBB) group(50 cases)and nonischemic cardiomyopathy with LBBB group(32 cases). The relationship between systolic synchrony parameters and systolic function parameters were analyzed with Pearson correlation analysis.Results:Statistic results for all patients showed that PSD and PHB were well correlated with LVEF( r values: -0.790, -0.799, both P<0.01), but PP was poorly correlated with LVEF( r=-0.194, P<0.01); HS, HK were positively correlated with LVEF( r values: 0.767, 0.676, both P<0.01); PSD, PHB were positively correlated with ESV( r values: 0.778, 0.795, both P<0.01) and EDV ( r values: 0.722, 0.732, both P<0.01); but PP was poorly correlated with ESV( r=0.145, P<0.01) and not correlated with EDV ( r=0.095, P>0.01). HS, HK were negatively correlated with EDV and ESV ( r values: -0.700 to -0.580, all P<0.01). PSD and PHB showed negatively correlation with LVEF ( r values: -0.834 to -0.492, all P<0.01), while HS, HK showed positive correlation with LVEF ( r values: 0.243-0.792, all P<0.01) in normal group, the ischemic cardiomyopathy group, the nonischemic cardiomyopathy without LBBB group and the nonischemic cardiomyopathy with LBBB group. Conclusions:The left ventricular systolic synchrony parameters provided by CZT SPECT GMPI correlate well with the left ventricular systolic function parameters, and the worse systolic function, the worse systolic synchrony. Both ischemic cardiomyopathy and non-ischemic cardiomyopathy can affect left ventricular mechanical contraction synchrony, and the effect on contraction synchrony in non-ischemic cardiomyopathy patients with LBBB is greater.

Objective:To investigate the expression of coxsackievirus-adenovirus receptor (CAR) in thymic carcinoma and the relationship between CAR and the antitumor activity of oncolytic adenovirus H101.Methods:The expression of CAR in thymic carcinoma tissues and cells were detected by RT-qPCR and Western blot. H101 expression and virus titers in Bcap-37, MP59 and T1889 cells after infection were detected by RT-qPCR and 50% tissue culture infectious dose (TCID 50). The proliferation activity and apoptosis rates of T1889 cells infected with H101 at different multiplicity of infection (MOI) were detected by CCK-8 and flow cytometry. CAR expression in T1889 cells treated with different concentrations of trichostatin A (TSA), a histone deacetylase inhibitor, was detected. H101 expression and virus titers in the TSA-treated and H101-infected cells were detected. Cell activity was detected by CCK-8. The phosphorylation levels of MARK and ERK1/2 and the expression of CAR at protein level in TSA-treated or TSA+ TBHQ (ERK activator) treated cells were detected. Results:CAR expression at both mRNA and protein levels were significantly lower in thymic carcinoma tissues than in adjacent normal tissues ( P<0.01), and lower in MP59 and T1889 cells than in thymic epithelial cells (TEC) and Bcap-37 cells ( P<0.01). H101 expression in MP59 and T1889 cells and the titers of H101 in culture supernatants were significantly lower than those in Bcap-37 cells ( P<0.01). Compared with Bcap-37 cell, the activity of MP59 and T1889 cells was significantly increased and the apoptosis rates were significantly decreased 48 h after H101 infection ( P<0.01). The expression of CAR at both mRNA and protein levels in T1889 cells treated with different concentrations of TSA increased in a dose-dependent manner. When T1889 cells were treated with 0.25 μmol/L of TSA, the expression of H101 at mRNA level and H101 titers were significantly increased ( P<0.05); the phosphorylation levels of MAPK and ERK1/2 proteins were continuously decreased; the expression of CAR was continuously increased. Compared with the TSA treatment group, the expression of CAR at protein level in the TSA+ TBHQ treatment group decreased significantly ( P<0.01), and the p-ERK1/2/ERK1/2 ratio increased significantly ( P<0.01). Conclusions:TSA could up-regulate CAR expression in thymic carcinoma by inhibiting the MARK/ERK1/2 pathway, thereby enhancing the antitumor activity of H101.

Objective: To compare the effect of intranasal dexmedetomidine and oral chloral hydrate in deep sedation of children. Methods: The Pubmed, EMBase, CENTRAL (Issue 4, 2018), Web of science, CBM, Wanfang Data, CNKI and VIP databases from the inception to January 2019 were searched. Randomized controlled trials (RCTs) with dexmedetomidine and chloral hydrate as interventions were included and the data were analyzed by RevMam 5.3 and Stata 12.0 software. The success rate of deep sedation, the indicator of sedation onset time, the recovery time, the incidence of vomiting and bradycardia were compared. Results: A total of 7 RCTs involving 1 007 patients were included for analysis. The results showed that the success rate of deep sedation (OR=2.55, 95%CI:1.46-4.44, P<0.01) and the incidence of bradycardia (OR=4.42, 95%CI:1.82-10.74, P<0.01) in the dexmedetomidine nasal group were significantly higher than those in the chloral hydrate oral group. The recovery time was significantly shorter (MD=-16.41, 95%CI:-21.54-11.28, P<0.01) and the incidence rate of vomiting (OR=0.04, 95%CI:0.01-0.17, P<0.01) in dexmedetomidine nasal group was significantly lower than those in the chloral hydrate oral group. There was no significant difference in the indicator of sedation onset time (MD=-0.47, 95%CI:-2.71-1.22, P=0.46). Conclusion Compared with the traditional oral chloral hydrate, intranasal dexmedetomidine has a higher sedation success rate and shorter recovery time after sedation with a lower incidence of nausea and vomiting.