Portal hypertension (PHT) is a common complication of liver cirrhosis, which could be measured by the means of portal vein pressure (PVP). However, there is no report about an effective and reliable way to achieve noninvasive assessment of PVP so far. In this study, firstly, we collected ultrasound images and echo signals of different ultrasound contrast agent (UCA) concentrations and different pressure ranges in a low-pressure environment based on an in vitro simulation device. Then, the amplitudes of the subharmonics in the echo signal were obtained by ultrasound grayscale image construction and fast Fourier transform (FFT). Finally, we analyzed the relationship between subharmonic amplitude (SA) and bionic portal vein pressure (BPVP) through linear regression. As a result, in the pressure range of 7.5–45 mm Hg and 8–20 mm Hg, the linear correlation coefficients (LCC) between SA and BPVP were 0.927 and 0.913 respectively when the UCA concentration was 1∶3 000, and LCC were 0.737 and 0.568 respectively when the UCA concentration was 1∶6 000. Particularly, LCC was increased to 0.968 and 0.916 respectively while the SAs of two UCA concentrations were used as the features of BPVP. Therefore, the results show a good performance on the linear relationship between SA and BPVP, and the LCC will be improved by using SAs obtained at different UCA concentrations as the features of BPVP. The proposed method provides reliable experimental verification for noninvasive evaluation of PVP through SA in clinical practice, which could be a guidance for improving the accuracy of PVP assessment.
Cryogels are a type of hydrogel material which are fabricated by cryopolymerization at subzero temperature. Due to their unique macroporous structure, shape memory properties and injectability, cryogels have gained significant interest in the fields of tissue engineering for encouraging the repair and regeneration of injured tissues. In this review, the basic concepts relevant to cryogels are introduced, and then the fabrication principle, the process parameters and the unique properties of cryogel are discussed. Next, the latest advances of cryogels as three-dimensional scaffold for various tissue engineering applications are given. Finally, this review summarizes the current limitations of cryogels, and strategies to further improve their properties for tissue engineering. The purpose of this article is to provide a reference guide for the researchers in related fields.
Steady-state visual evoked potential (SSVEP) is one of the commonly used control signals in brain-computer interface (BCI) systems. The SSVEP-based BCI has the advantages of high information transmission rate and short training time, which has become an important branch of BCI research field. In this review paper, the main progress on frequency recognition algorithm for SSVEP in past five years are summarized from three aspects, i.e., unsupervised learning algorithms, supervised learning algorithms and deep learning algorithms. Finally, some frontier topics and potential directions are explored.
【摘要】 目的 了解新护士的心理健康状况及应付方式。 方法 采用心理卫生自评量表（SCL-90）和应付方式量表对2008年1月-2009年12月新上岗的64名护士进行测查。 结果 新护士强迫症状、抑郁、焦虑、敌对、恐怖、偏执、精神病性因子分、总均分及阳性项目数与全国常模比较偏高，差异有统计学意义（Plt;0.05）；SCL-90阳性者与阴性者应付方式比较，阳性者自责、幻想、退避、合理化因子均分均高于阴性者，差异有统计学意义（Plt;0.01）；新护士应付方式各因子均分、退避、幻想、自责因子均高于吴超等人的研究（Plt;0.05）。 结论 新护士心理健康状况低于一般人群；较其他年龄段护士更多采用不成熟应付方式；成熟应付方式有益心理健康。护理管理者应重视新护士心理健康，引导新护士多采取成熟应付方式，提高心理健康水平。【Abstract】 Objective To evaluate the psychological states of new nurses and their coping styles. Methods Sixty-four nurses starting work between January 2008 and October 2009 in our hospital were investigated by Symptom Checklist 90 (SCL-90) and Coping Style Questionnaire. Results The scores of compulsion and mental disorder, average score, and the number of positive items were statistically higher than the national norm of China (Plt;0.001). The scores of athymia, anxiety, hostility, and phobia factors were higher than the national norm (Plt;0.01). The score of paranoid factor was also statistically higher than the national norm (Plt;0.05). Based on the results of SCL-90, we found that the scores of factors of self-accusation, fantasy, back-off (Plt;0.05) and the factor of rationalization (Plt;0.01) in the positive group were significantly higher than those of the negative group. Compared with the result of the research made by WU Chao and his colleges, the average scores of such factors as back-off (Plt;0.001), fantasy (Plt;0.01) and self-accusation (Plt;0.05) were statistically higher in the study group than those in the control group. Conclusion The psychological states of new nurses are worse than the general population. Compared with older nurses, new nurses are more inclined to use immature coping styles. Mature coping styles are favorable to their psychological states. The nursing regulators should pay more attention to the psychological states of new nurses and guide them to use mature coping styles to improve their psychological states.
Ultrasound is the best way to diagnose thyroid nodules. To discriminate benign and malignant nodules, calcification is an important characteristic. However, calcification in ultrasonic images cannot be extracted accurately because of capsule wall and other internal tissue. In this paper, deep learning was first proposed to extract calcification, and two improved methods were proposed on the basis of Alexnet convolutional neural network. First, adding the corresponding anti-pooling (unpooling) and deconvolution layers (deconv2D) made the network to be trained for the required features and finally extract the calcification feature. Second, modifying the number of convolution templates and full connection layer nodes made feature extraction more refined. The final network was the combination of two improved methods above. To verify the method presented in this article, we got 8 416 images with calcification, and 10 844 without calcification. The result showed that the accuracy of the calcification extraction was 86% by using the improved Alexnet convolutional neural network. Compared with traditional methods, it has been improved greatly, which provides effective means for the identification of benign and malignant thyroid nodules.
Objective To explore the feasibility and effectiveness of maintaining the reduction of unstable intertrochanteric fractures by Kirschner wire-fixation-cortical bone technique. Methods Forty patients with intertrochanteric fracture [AO/Orthopaedic Trauma Association (AO/OTA) type 31-A2.2] admitted between May 2015 and January 2017 and requiring closed reduction and proximal femoral nail antirotation (PFNA) were randomly divided into trial group (intraoperative Kirschner wire-fixation-cortical bone technique group, 20 cases) and control group (conventional treatment group, 20 cases). There was no significant difference in general data of gender, age, side, body mass index, cause of injury, time from injury to operation between the two groups (P>0.05). The operation time, intraoperative blood loss, and intraoperative fluoroscopy times of the two groups were recorded; the reduction quality of fracture was observed according to the corresponding relationship between medial and anterior cortex (positive, neutral, and negative support) of intraoperative fluoroscopy proposed by ZHANG Shimin, and the stability of internal fixation and fracture healing were observed; Harris score was used to evaluate the recovery of hip function at 12 months after operation. Results In the trial group, 6 cases (30%) had 2 Kirschner wires implanted less than 4 times, 7 cases (35%) had 5-8 times, and 7 cases (35%) had 9 times or more. There was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05), but the blood transfusion volume and intraoperative fluoroscopy times in the trial group were significantly less than those in the control group (P<0.05). Both groups were followed up 13-21 months, with an average of 17 months. There was no complications such as wound infection, deep venous thrombosis of lower extremities, refracture, and internal fixation-related complications. The quality of intraoperative reduction in the trial group was significantly better than that in the control group (Z=–2.794, P=0.024). The Harris score of the trial group was significantly better than that of the control group at 12 months after operation (t=2.98, P=0.01). Conclusion The use of Kirschner wire-fixation-cortical bone technique during intertrochanteric fracture closed reduction and PFNA internal fixation surgery can effectively maintain the reduction effect, reduce the number of fluoroscopy, improve the reduction quality, reduce allogeneic blood input, obtain better hip function, and do not increase the operation time and intraoperative blood loss.
Objective To explore the correlation between the imaging features of peripheral ground-glass pulmonary nodules and the invasion degree of lung adenocarcinoma, and the high risk factors for infiltrating lung adenocarcinoma under thin-slice CT, which provides some reference for clinicians to plan the surgical methods of pulmonary nodules before operation and to better communicate with patients, and assists in building a clinical predictive model for invasive adenocarcinoma. MethodsClinical data of the patients with peripheral ground-glass pulmonary nodules (diameter≤3 cm) in thin-slice chest CT in the First Affiliated Hospital of Soochow University from January 2019 to January 2020 were continuously collected. All patients underwent thin-slice CT scan and thoracoscopic surgery in our center. According to the pathological examination results, they were divided into two groups: an adenocarcinoma lesions before infiltration group, and an invasive lung adenocarcinoma group. The thin-slice CT imaging parameters of pulmonary nodules were collected. The nodular diameter, mean CT value, consolidation tumor ratio (CTR), nodular shape, vacuolar sign, bronchial air sign, lobulation sign, burr sign, lesion boundary, pleural depression sign, vascular cluster sign and other clinical data were collected. Univariate and multivariate analyses were conducted to analyze the independent risk factors for the infiltrating lung adenocarcinoma, and to analyze the threshold value and efficacy of each factor for the identification of infiltrating lung adenocarcinoma. Results Finally 190 patients were enrolled. There were 110 patients in the adenocarcinoma lesions before infiltration group, including 21 males and 89 females with a mean age of 53.57±10.90 years, and 80 patients in the invasive lung adenocarcinoma group, including 31 males and 49 females with a mean age of 56.45±11.30 years. There was a statistical difference in the mean CT value, nodular diameter, CTR, gender, smoking, nodular type, nodular shape, vacuolar sign, lobulation sign, burr sign, lesion boundary, pleural depression sign, vascular cluster sign between the two groups (P＜0.05). However, there was no statistical difference between the two groups in age (P=0.081), lesion site (P=0.675), and bronchial air sign (P=0.051). Multiple logistic regression analysis showed that nodular diameter, mean CT value, CTR and lobulation sign were independent risk factors for differentiating preinvasive adenocarcinoma from invasive adenocarcinoma. At the same time, the threshold value was calculated by Youden index, indicating that the CTR was 0.45, the nodal diameter was 10.5 mm and the mean CT value was –452 Hu. Conclusion In the peripheral ground-glass pulmonary nodules, according to the patient's CT imaging features, such as mixed ground-glass nodules, irregular shapes, vacuoles, short burrs, clear boundaries, pleural indentations, and vascular clusters, have a certain reference value in the discrimination of the invasion degree of ground-glass pulmonary nodules. At the same time, it is found in this research that peripheral ground-glass pulmonary nodules with diameter greater than 10.5 mm, CT value greater than –452 Hu, CTR greater than 0.45 and lobulation sign are more likely to be infiltrating lung adenocarcinoma.
Objective To compare the effectiveness of three surgical methods in the treatment of Pauwels type Ⅲ femoral neck fracture in young and middle-aged patients, in order to provide reference for clinical selection of appropriate surgical methods. Methods The clinical data of 103 patients with Pauwels type Ⅲ femoral neck fracture who met the selection criteria between June 2018 and December 2021 were retrospectively analyzed. The fractures were fixed with hollow screws in an inverted triangular shape (37 cases, hollow screw group), hollow screws in an inverted triangular shape combined with eccentric shaft screw (34 cases, eccentric shaft screw group), and hollow screws in an inverted triangular shape combined with medial support plate (32 cases, support plate group). There was no significant difference in age, gender, cause of injury, body mass index, time from injury to operation, side of the fracture, and Garden classification, whether they were in traction preoperatively, and other baseline data between groups (P>0.05). The operation time, intraoperative blood loss, the number of fluoroscopy, the length of hospital stay, early postoperative complication and postoperative weight-bearing time of the three groups were recorded. Harris score was used to evaluate joint function at 6 and 12 months after operation, and the difference between the two time points (change value) was calculated for comparison between groups. X-ray films were reviewed to evaluate the quality of fracture reduction (Garden index) and healing, as well as the occurrence of internal fixation failure and femoral head necrosis. Results The patients of the three groups were successfully completed. Compared with the hollow screw group and the eccentric shaft screw group, the operation time and intraoperative blood loss of the support plate group significantly increased, the number of fluoroscopy reduced, and the quality of fracture reduction was better, the differences were significant (P<0.05). The operation time, intraoperative blood loss, and the number of fluoroscopy of the hollow screw group were less than those of the eccentric shaft screw group, the differences were significant (P<0.05). There was no significant difference in the length of hospital stay between groups (P>0.05). All patients in the three groups were followed up 21-52 months, with an average follow-up time of 36.0 months, and there was no significant difference between groups (P>0.05). The incisions of all patients healed by first intention. Imaging reexamination showed that there was no significant difference in the incidence of fracture nonunion between groups (P>0.05). The fracture healing, partial weight-bearing, and full weight-bearing were significantly earlier in the eccentric shaft screw group and the support plate group than in the hollow screw group (P<0.05). There was no significant difference in change value of Harris score, the incidence of postoperative deep venous thrombosis and femoral head necrosis between groups (P>0.05); however, the incidence of internal fixation failure in the support plate group and the eccentric shaft screw group was significantly lower than that in the hollow screw group (P<0.05). The incidence of postoperative lateral thigh irritation in the support plate group was significantly lower than that in the hollow screw group (P<0.05); there was no significant difference between the eccentric shaft screw group and the other two groups (P>0.05). The overall incidences of postoperative complications in the eccentric shaft screw group and the support plate group were significantly lower than that in the hollow screw group (P<0.05). Conclusion For young and middle-aged patients with Pauwels type Ⅲ femoral neck fracture, compared with simple hollow screw fixation in an inverted triangular shape, combined with medial support plate or eccentric shaft screw internal fixation can shorten the fracture healing time, reduce the incidences of postoperative complication, more conducive to early functional exercise of the affected limb; at the same time, the operation time and blood loss of combined eccentric shaft screw internal fixation are less than those of combined medial support plate internal fixation, so the hollow screw in an inverted triangular shape combined with eccentric shaft screw fixation may be a better choice.
ObjectiveTo design a ventilator humidifier that can ensure water level and infuse fluid automatically, and evaluate its application effect in patients with mechanical ventilation.MethodsThirty-eight patients who received mechanical ventilation in ICU from March to June in 2019 were included. According to the order of admission, they were divided into a study group with 18 patients and a control group with 20 patients. Different ventilator humidifiers were used. The study group used self-designed ventilator humidifier, and the control group used the MR370 humidifier. The cases of sputum viscosity with Ⅲ degree after 48 hours’ mechanical ventilation, the times of fluid infusion and the total amount of fluid infusion were compared. The times of pouring out condensate water and the total amount of pouring out condensate water in 24 hours were also compared.ResultsThe times of infusing liquid in the study group in 24 hours was less than that in the control group (3.3±0.5 vs. 11.2±1.7, P<0.01), but the other indicators were not statistically significant between the two groups (all P>0.05).ConclusionsThe self-designed ventilator humidifier can be used for patients with mechanical ventilation, which can keep the water level at the water line all the time and is beneficial to humidification treatment. It can reduce the times of fluid infusion and nurses' workload.