Objective: To investigate the epidemiological characteristics of varicella outbreaks in primary and middle schools, and to establish a risk predictive model, so as to provide scientific guidance for the prevention of varicella outbreaks in schools. Methods: Based on a nested case-control study, primary and middle schools in 4 districts of Shanghai (Yangpu District and Jingan District) and Hangzhou (Xiaoshan District and Linping District) from January to December 2023 were selected to observe the status of varicella outbreaks. Associated factors of varicella outbreaks were investigated and used for establishing the predictive model, which was evaluated by the Hosmer-Lemeshow(H-L) goodness of fit test, receiver operating characteristic (ROC) curve, Calibration curve, decision curve analysis (DCA). Results: A total of 98 varicella outbreaks were included, with 195 schools without varicella outbreaks during the same period as controls. Eight factors, including the availability of warm water in restroom, availability of hand soap in restroom, average class size, duration of student attendance at school per day, presence of a fulltime school doctor, hesitancy of the school principal towards varicella vaccination, and rates of first and second doses of varicella vaccination, were identified as potential factors for school varicella outbreaks, with statistically significant differences (χ2/Z=10.01, 20.49, 17.43, 9.74, 32.17, 6.60, 2.20, 3.39, P<0.05). The 8 variables above were employed to construct a risk predictive model, and Hosmer-Lemeshow goodness of fit test yielded a χ2 value of 5.863 (P>0.05); the area under the ROC curve (AUC) was 0.846 (95%CI=0.799-0.893); Calibration curve analysis indicated good consistency between predicted and actual values of the model. DCA demonstrated favorable predictive performance of the model over a wide range. Conclusions The predictive model for school varicella outbreaks demonstrates satisfactory accuracy and efficacy. It suggested to make good use of this prediction model and take relevant measures to reduce the risk of varicella transmission in schools.

To investigate tick species and prevalence of Anaplasmataceae and spotted fever group Rickettsia(SFGR)in ticks collected from sheep and goats in Leibo county,Sichuan Province.Ticks were preliminary identified by morphological characters and the genomic DNAs of ticks were ex-tracted.Molecular detection was performed by PCR targeting gene fragment of tick ITS-2,gltA and ompA genes of Rickettsia spp.,16S rRNA and rpoB genes of Anaplasma spp.and Ehrlichia spp.Positive PCR products were sequenced and phylogenetic trees were built based on these genes.The results showed that a total of 353 adult ticks collected from sheep and goats were identified as H.longicornis.The total prevalence of SFGR in H.longicornis was 22.66％(80/353)with only R.raoultii detected,which was closely related to R.raoultii(JQ792163)isolated from Dermacentor niveus in Tibet.The total prevalence of Anaplasmataceae was 87.82％(310/353)with six Ana-plasma species(A.bovis,A.capra,A.marginale,Anaplasma cf.marginale,Anaplasma sp.,Can-didatus A.mediterraneum)and two Ehrlichia species(E.chaffeensis and Ehrlichia sp.)detec-ted.Go-infection was found in some H.longicornis as high as 7.37％(26/353).The results indica-ted that H.longicornis may be the dominant tick species in Leibo county with high infections rates of Anaplasmataceae and SFGR.The close monitoring of the tick-borne pathogens should be strengthened in the future research work.

Objective To explore the value of machine learning(ML)models based on non-contrast CT(NCCT)radiomics features for predicting the severity of acute phase traumatic brain injury(TBI).Methods Totally 600 TBI patients were retrospectively collected as observation group,other 65 TBI patients were taken as external validation set,while 50 TBI patients were prospectively enrolled as prospective validation set.Patients in observation group were divided into high-risk subgroup(n=240)and low-risk subgroup(n=360)according to Glasgow outcome scale(GOS)at discharge.The severity of acute phase TBI in observation group was assessed by doctor A and B with the same criteria,then an artificial model was established based on clinical and NCCT data at the time of first diagnosis using logistic regression(LR)method for predicting the severity of acute phase TBI.Patients in observation group were divided into training set(n=420,including 168 in high-risk subgroup and 252 in low-risk subgroup)and test set(n=180,including 72 in high-risk subgroup and 108 in low-risk subgroup)at the ratio of 7∶3.Based on NCCT of training set,radiomics features were extracted and selected,and LR,support vector machine(SVM),random forest(RF)and K-nearest neighbor(KNN)were used to establish 4 ML models.The efficacies of the above models were validated in test set,external validation set(including 34 cases of high-risk and 31 cases of low-risk TBI)and prospective validation set(including 21 cases of high-risk and 29 cases of low-risk TBI),respectively.Results The area under the curve(AUC)of doctor A and B for evaluating the severity of acute phase TBI in observation group was 0.606 and 0.771,respectively,of artificial model was 0.824.Based on NCCT in training set,6 optimal radiomics features were selected to construct LR,SVM,RF and KNN ML models,with AUC of 0.983,0.971,0.970 and 0.984 in test set,respectively,while the AUC of artificial model was 0.708.The AUC of LR,SVM,RF,KNN ML models and artificial model in external validation set was 0.879,0.881,0.984,0.863 and 0.733,while in prospective validation set was 0.984,0.873,0.982,0.897 and 0.704,respectively.Conclusion ML models based on CT radiomics could effectively predict the severity of acute phase TBI.

Objective:To compare the effect of O-arm assisted and free-hand pedicle screw placement in the treatment of AO type C thoracolumbar fracture.Methods:A retrospective cohort study was used to analyze the clinical data of 34 patients with type C thoracolumbar fracture admitted to Henan Provincial People′s Hospital from January 2018 to June 2021, including 23 males and 11 females; aged 42-63 years [(50.4±7.4)years]. The fracture was located at T 11 in 4 patients, T 12 in 10, L 1 in 12, L 2 in 6, T 11~12/L 1 in 1 and T 12/L 1 in 1. Posterior reduction and internal fixation was carried out for all patients, of whom 18 were treated with O-arm assisted pedicle screw placement (navigation group) and 16 with free-hand pedicle screw placement (free-hand group). The operation time, single screw placement time, intraoperative bleeding volume, operation mode and screw placement accuracy were compared between the two groups. The kyphotic Cobb angle, visual analogue score (VAS) and American Spinal Injury Association (ASIA) score were compared between the two groups before operation, at 1 week after operation, at 3 months after operation and at the last follow-up. Postoperative complications were observed. Results:All patients were followed up for 12-29 months [(16.8±6.1)months]. There was no significant difference between the two groups in the operation time, intraoperative bleeding volume and operation mode (all P>0.05). The single screw placement time was (9.4±1.6)minutes in navigation group, but was (10.8±1.5)minutes in free-hand group ( P<0.05). The screw placement accuracy was 97.4% in navigation group, but was 81.5% in free-hand group ( P<0.01). The kyphotic Cobb angle and VAS had no significant differences between the two groups before operation (all P>0.05). The kyphotic Cobb angle in navigation group and free-hand group was (4.3±1.1)° and (5.9±1.1)° at 1 week after operation, (4.4±1.2)° and (5.7±1.3)° at 3 months after operation, and (4.4±1.2)° and (6.8±0.9)° at the last follow-up, decreased significantly from that before operation [(21.8±3.1)°, (22.2±3.2)°] (all P<0.01). The kyphotic Cobb angle in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The VAS in navigation group and free-hand group was (3.2±0.7)points and (4.1±0.7)points at 1 week after operation, (2.4±0.6)points and (3.0±0.8)points at 3 months after operation, and (1.8±0.9)points and (2.6±0.7)points at the last follow-up, decreased significantly from that before operation [(8.4±0.8)points, (8.3±0.9)points] (all P<0.01). The VAS in navigation group was significantly lower than that in free-hand group at 1 week, 3 months after operation and at the last follow-up (all P<0.01). The ASIA score showed no significant difference within and between the two groups before operation, at 1 week, 3 months after operation and at the last follow-up (all P>0.05). Postoperative incision infection occurred in 1 patient in both groups ( P>0.05). Implant failure such as loosening or displacement was not observed in navigation group, and only occurred in 2 patients in free-hand group ( P>0.05). Conclusion:Compared with free-hand pedicle screw placement, O-arm assisted pedicle screw placement in the treatment of AO type C thoracolumbar fracture has advantages of rapid and accurate screw placement, good reduction and notable pain relief.

L-asparaginase (L-ASN) is widely applied in the treatment of malignant tumor and low-acrylamide food production, however, the low expression level hampers its application. Heterologous expression is an effective strategy to increase the expression level of target enzymes, and Bacillus is generally used as the host for efficient production of enzymes. In this study, the expression level of L-asparaginase in Bacillus was enhanced through optimization of expression element and host. Firstly, five signal peptides (SP_SacC, SP_AmyL, SP_AprE, SP_YwbN and SP_WapA) were screened, among which SP_SacC showed the best performance, reaching an activity of 157.61 U/mL. Subsequently, four strong promoters (P43, P_ykzA-P43, P_Ubay and P_bacA) from Bacillus were screened, and tandem promoter P_ykzA-P43 showed the highest yield of L-asparaginase, which was 52.94% higher than that of control strain. Finally, three Bacillus expression hosts (B. licheniformis Δ0F3 and BL10, B. subtilis WB800) were investigated, and the maximum L-asparaginase activity, 438.3 U/mL, was reached by B. licheniformis BL10, which was an 81.83% increase compared with that of the control. This is also the highest level of L-asparaginase in shake flask reported to date. Taken together, this study constructed a B. licheniformis strain BL10/P_ykzA-P43-SP_SacC-ansZ capable of efficiently producing L-asparaginase, which laid the foundation for industrial production of L-asparaginase.
Bacillus licheniformis/metabolism* ; Asparaginase/genetics* ; Bacillus/genetics* ; Protein Sorting Signals ; Promoter Regions, Genetic/genetics* ; Bacillus subtilis/genetics* ; Bacterial Proteins

Objective:To explore the correlation of serum albumin level at admission with clinical prognoses in patients with acute traumatic brain injury (TBI).Methods:One hundred and fifty-four patients with acute moderate-extreme severe TBI (Glasgow Coma Scale [GCS] scores of 3-12 at admission) in Department of Neurosurgery, General Hospital of Western Theater Command from January 1, 2019 to December 31, 2020 were chosen. The comprehensive clinical data of these patients were collected, including age, gender, GCS scores, serum albumin level (hypoalbuminemia defined as<35 g/L), hemoglobin level, comorbidities, treatment measures, and prognoses 6 months after discharge (poor prognosis defined as Glasgow outcome Scale [GOS] scores of 1-2, and good prognosis defined as GOS scores of 3-5). Univariate and multivariate Logistic regressions were used to identify the independent factors for clinical prognoses of these patients, and differences in poor prognosis rate, length of ICU stay, and total hospital cost were compared between different groups.Results:Among the 154 patients, 43 had poor prognosis and 111 had good prognosis. Serum albumin level at admission ( OR=0.916, 95% CI: 0.843-0.996, P=0.001) and GCS scores at admission ( OR=0.701, 95% CI: 0.594-0.828, P<0.001) were independent factors for prognosis. Patients with hypoalbuminemia ( n=70) displayed significantly higher poor prognosis rate, longer ICU stays, and increased total hospitalization cost compared with those without hypoalbuminemia ( n=84, P<0.05); specifically, in patients with GCS scores of 9-12 at admission ( n=58), those with hypoalbuminemia ( n=27) exhibited significantly higher poor prognosis rate, longer ICU stays, and higher total hospitalization cost than their non-hypoalbuminemia counterparts ( n=31, P<0.05); similarly, in patients with GCS scores of 3-8 at admission ( n=96), those with hypoalbuminemia ( n=74) had significantly higher poor prognosis rate than their non-hypoalbuminemia counterparts ( n=22, P<0.05). In patients with good prognosis, those with hypoalbuminemia ( n=56) showed significantly longer total hospital stays, prolonged ICU stays, and increased total hospitalization cost compared with those without hypoalbuminemia ( n=55, P<0.05). Conclusion:Low serum albumin level at admission is likely to lead to poor prognosis, prolonged ICU stays and increased total hospitalization cost in patients with acute TBI.

OBJECTIVE: To assess the practical and health economical values of non-invasive prenatal test (NIPT) in Changsha Municipal Public Welfare Program. METHODS: A retrospective analysis was carried out on 149 165 women undergoing NIPT test from April 9, 2018 to December 31, 2019. For pregnant women with high risks, invasive prenatal diagnosis and follow-up of pregnancy outcome were conducted. The cost-benefit of NIPT for Down syndrome was analyzed. RESULTS: NIPT was carried out for 149 165 pregnant women and succeeded in 148 749 cases (99.72%), for which outcome were available in 148 538 (99.86%). 90% of pregnant women from the region accepted the screening with NIPT. 415 (0.27%) were diagnosed as high risk. Among these, 381 (91.81%) accepted amniocentesis, which led to the diagnosis of 212 cases of trisomy 21 (PPV=85.14%), 41 cases with trisomy 18 (PPV=48.81%) and 10 cases with trisomy 13 (PPV=20.83%). The sensitivity and specificity of NIPT for trisomy 21, trisomy 18 and trisomy 13 were (97.70%, 99.98%), (97.62%, 9.97%) and (100%, 99.97%), respectively. In addition, 213 and 30 cases were diagnosed with sex chromosomal aneuploidies (PPV=46.2%) and other autosomal anomalies (PPV=16.57%), respectively. For Down syndrome screening, the cost and benefit of the project was 120.79 million yuan and 1,056.95 million yuan, respectively. The cost-benefit ratio was 1: 8.75, and safety index was 0.0035. CONCLUSION NIPT is a highly accurate screening test for trisomy 21, which was followed by trisomy 18 and sex chromosomal aneuploidies, while it was less accurate for other autosomal aneuploidies. The application of NIPT screening has a high health economical value.
Aneuploidy ; Cost-Benefit Analysis ; Female ; Humans ; Noninvasive Prenatal Testing ; Pregnancy ; Retrospective Studies ; Trisomy 18 Syndrome/genetics*

Objective:To investigate the difference in efficacy between transsylvian-transinsular approach and transcortical-transtemporal approach for hematoma evacuation in the treatment of severe basal ganglia intracerebral hemorrhage in young adults.Methods:Young adult patients with severe intracerebral hemorrhage in the basal ganglia region underwent craniotomy hematoma removal in Ankang Central Hospital from February 2012 to February 2021 were retrospectively enrolled. The Glasgow Outcome Scale score was used to evaluate the outcome at 6 months after onset. 4-5 were defined as good outcome and 1-3 were defined as poor outcome. Multivariate logistic regression analysis was used to determine the independent influencing factors of the poor outcomes. Results:A total of 51 patients were enrolled. Their median age was 41 (interquartile range 39-43) years, and 29 were men (56.8%). The median Glasgow Coma Scale score at admission was 6.0 (interquartile range 5.5-7.0), and the median baseline hematoma volume was 38.0 ml (34.5-47.5 ml). Twenty-one patients (41.2%) were in the transsylvian-transinsular approach group and 30 (58.8%) were in the transcortical-transtemporal approach group. There were no significant differences in demographics, vascular risk factors and baseline clinical data between the transsylvian-transinsular approach group and the transcortical-transtemporal approach group. Compared with the transcortical-transtemporal approach group, the amount of intraoperative bleeding and hematoma residue in the transsylvian-transinsular approach group were less, the proportion of patients requiring decompressive craniectomy was lower (33.3% vs. 63.3%; χ2=4.449, P=0.035), and the duration of dehydration medication and hospital stay were shorter (all P<0.05). However, there was no significant difference in the good outcome rate between the two groups (66.7% vs. 56.7%; χ2=0.518, P=0.472). Multivariate logistic regression analysis showed that lower scores of Glasgow Coma Scale at admission (odds ratio 0.128, 95% confidence interval 0.017-0.977; P=0.047) and longer hospital stay (odds ratio 1.402, 95% confidence interval 1.065-1.844; P=0.016) were independently associated with the poor outcomes. Conclusion:For young adult patients with severe basal ganglia intracerebral hemorrhage who underwent hematoma removal, although there was no significant difference between the outcomes of patients with transsylvian-transinsular approach and transcortical-transtemporal approach, the former had more advantages.

Objective:To investigate the effectiveness of postoperative radiotherapy using shrinking field for patients with extremity soft tissue sarcoma (STS), mainly focusing on the local control rate and adverse events.Methods:Clinical data of 49 extremity STS patients who received postoperative intensity-modulated radiotherapy in the First Hospital of Tsinghua University from October 2017 to March 2021 were retrospectively analyzed. Target volumes were contoured on CT and MRI fusion images. The tumor bed was defined as GTV tb, with 3 cm expansion in the longitudinal direction and 1.5 cm expansion in the radial direction to construct CTV (the target volume should be properly repaired according to the anatomical barrier, and the edema area around the tumor should be included). GTV tb and CTV were expanded in all directions by 0.5 cm to construct PTV1 and PTV2 respectively, at a dose of 95%PTV1 63-66 Gy, 95%PTV2 50-56 Gy,1.8-2.0 Gy/f. The dose of surgical volume should be given at 70 Gy for patients who had a microscopic positive margin. Results:The median follow-up time was 32.1 months (7.9-45.6 months). The 3-year local failure-free survival (LFFS), overall survival (OS)and distant metastasis-free survival (DMFS) were 91.7%,77.6% and 71.5%, respectively. Univariate analysis showed that patients with a microscopic positive margin were more likely to develop local recurrence ( P<0.05). The incidence of grade 2 or above wound complications, joint stiffness, fracture, edema and skin fibrosis were 2%, 4.1%, 2%, 8.2% and 26.5%, respectively. Conclusion:Postoperative radiotherapy with shrinking field provides excellent local control rate and low incidence of late adverse events in patients with extremity STS.

Objective:To evaluate the efficacy of posterior subtotal vertebrectomy in the treatment of thoracolumbar vertebral refractures after vertebroplasty.Methods:A retrospective analysis was conducted in the 28 patients with refracture after percutaneous vertebroplasty(PVP) or percutaneous kyphoplasty(PKP) who had been treated at Department of Spinal Surgery, Henan Provincial People's Hospital from June 2017 to October 2019. They were 7 males and 21 females, with an average age of 62.4 years(from 61 to 76 years). A total of 28 vertebrae were involved, including 5 T11s, 9 T12s, 11 L1s and 3 L2s. Their previous operations were PKP in 17 cases and PVP in 11. After the spinous process, vertebral plate, articular process and transverse process were resected by posterior approach, the vertebral body, bone cement and upper and lower intervertebral discs were partially resected by trans-vertebral lateral approach. At the same time, nerve decompression was performed. Finally, the inter-vertebral support was fixated followed by the posterior screw-rod orthopedic fixation. The operation time and intraoperative bleeding volume were recorded. The cobb angles of kyphosis were compared on the X-ray films of the whole spine between preoperation and the last follow-up to evaluate correction. Functional improvement of the spine was evaluated by comparison of the visual analogue scale (VAS) and JOA(Japanese Orthopedics Association) scores between preoperation and the last follow-up.Results:The operation time averaged 182.1 min and intraoperative bleeding volume 996.2 mL. All the 28 patients were followed up for 8 to 29 months (mean, 19.8 months). No obvious neurological lesions or other serious complications were observed. The cobb angle was improved from preoperative 41.3°±10.3° to 6.4°±2.5° at the last follow-up, the VAS score from preoperative 7.3±1.8 to 2.5±1.0 at the last follow-up, and the JOA score from preoperative 8.4±2.3 to 21.3±2.5 at the last follow-up, showing a significant difference in all the comparisons ( P<0.05). Conclusion:The posterior subtotal vertebrectomy is effective for thoracolumbar vertebral refractures after vertebroplasty because it can remove bone cement, decompress the spinal canal, fuse the inter-vertebral graft and reconstruct the spinal stability in one stage.