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 explore the relationship between alterations of neural network plasticity and spatial learning and memory functions in mouse models with depression-like behaviors.Methods C57Thy1-YFP/GAD67-GFP mice were randomized into control group(with no treatment)and chronic unpredictable mild stress(CUMS)group(n=15)subjected to CUMS for 8 weeks.Depression-like behaviors of the mice were assessed using sucrose preference test,open field test,and forced swimming test,and their spatial learning and memory abilities were evaluated using Morris water maze test.The changes in the firing patterns of different neuronal subtypes were detected in the central nucleus of the amygdala(CeA)and the prelimbic cortex(PrL)using whole-cell patch-clamp technique.Results Compared with the control mice,CUMS mice showed significantly decreased sucrose preference,total distance moved,number of grid-crossings,entries into the central area,and time spent in the central area in the open field test(P<0.01).In the forced swimming test,CUMS mice exhibited obviously shortened time of struggling,swimming,and climbing with increased immobility time.In Morris water maze test,CUMS mice showed significantly increased escape latency and path length,decreased percentage of distance and swimming time within the target quadrant,and increased first entry latency into the target zone and swimming time within the opposite quadrant.Exposure to CUMS resulted in significantly enhanced energy barrier and increased absolute refractory period and inter-spike interval of glutamatergic neurons in the CeA and GABAergic neurons in the PrL,while the opposite changes were observed in GABAergic neurons in the CeA and glutamatergic neurons in the PrL.Conclusion CUMS-induced depression may lead to plastic changes in the excitatory and inhibitory neuronal networks within the CeA and PrL to cause impairment of spatial learning and memory abilities in mice.

Objective To explore the relationship between alterations of neural network plasticity and spatial learning and memory functions in mouse models with depression-like behaviors.Methods C57Thy1-YFP/GAD67-GFP mice were randomized into control group(with no treatment)and chronic unpredictable mild stress(CUMS)group(n=15)subjected to CUMS for 8 weeks.Depression-like behaviors of the mice were assessed using sucrose preference test,open field test,and forced swimming test,and their spatial learning and memory abilities were evaluated using Morris water maze test.The changes in the firing patterns of different neuronal subtypes were detected in the central nucleus of the amygdala(CeA)and the prelimbic cortex(PrL)using whole-cell patch-clamp technique.Results Compared with the control mice,CUMS mice showed significantly decreased sucrose preference,total distance moved,number of grid-crossings,entries into the central area,and time spent in the central area in the open field test(P<0.01).In the forced swimming test,CUMS mice exhibited obviously shortened time of struggling,swimming,and climbing with increased immobility time.In Morris water maze test,CUMS mice showed significantly increased escape latency and path length,decreased percentage of distance and swimming time within the target quadrant,and increased first entry latency into the target zone and swimming time within the opposite quadrant.Exposure to CUMS resulted in significantly enhanced energy barrier and increased absolute refractory period and inter-spike interval of glutamatergic neurons in the CeA and GABAergic neurons in the PrL,while the opposite changes were observed in GABAergic neurons in the CeA and glutamatergic neurons in the PrL.Conclusion CUMS-induced depression may lead to plastic changes in the excitatory and inhibitory neuronal networks within the CeA and PrL to cause impairment of spatial learning and memory abilities in mice.

[摘 要] 目的：重新评价卡瑞利珠单抗联合阿帕替尼治疗原发性肝癌（PHC）的有效性和安全性。方法：回顾性收集2019年1月至2021年5月在安徽医科大学附属第一医院确诊的PHC患者的临床资料。所有患者均接受卡瑞利珠单抗200 mg q3w联合阿帕替尼250 mg qd×21 d治疗。应用卡方检验进行基线特征比较，采用Kaplan-Meier法进行生存分析，从中估计中位总生存期（OS），然后采用Log-Rank检验进行比较；采用单因素Cox回归分析预测影响OS的因素。结果：本研究共纳入43例PHC患者，一线治疗患者的客观缓解率（ORR）为23.3%（7/30），二线及以上治疗患者的ORR为15.4%（2/13）。两组患者的疾病控制率（DCR）分别为83.3%（25/30）和61.5%（8/13），中位无进展生存期（PFS）分别为5.0个月（95% CI 3.2，6.8）和4.0个月（95% CI 1.7，6.3）（P=0.514），中位OS分别为13.0个月（95% CI 11.2，14.8）和9.0个月（95% CI 2.8，15.2）（P=0.179）。在43例患者中，33例（76.7%）存在3级或以上的治疗相关不良反应（AE）；最常见的AE为血小板计数下降（14.0%）、高血压（9.3%）和蛋白尿（9.3%）。Cox单因素回归分析显示，Child-Pugh分级是影响PHC患者预后的独立危险因素[HR=0.324，95% CI （0.146，0.716），P<0.05]。结论：卡瑞利珠单抗联合阿帕替尼可显著改善PHC患者的OS、ORR和DCR，AE可控。

Objective:To evaluate the value of preoperative prediction of vessel invasion (VI) of locally advanced gastric cancer by machine learning model based on the venous phase enhanced CT radiomics features.Methods:A retrospective analysis of 296 patients with locally advanced gastric cancer confirmed by pathology in the First Affiliated Hospital of Zhengzhou University from July 2011 to December 2020 was performed. The patients were divided into VI positive group ( n=213) and VI negative group ( n=83) based on pathological results. The data were divided into training set ( n=207) and test set ( n=89) according to the ratio of 7∶3 with stratification sampling. The clinical characteristics of patients were recorded, and the independent risk factors of gastric cancer VI were screened by multivariate logistic regression. Pyradiomics software was used to extract radiomic features from the venous phase enhanced CT images, and the minimum absolute shrinkage and selection algorithm (LASSO) was used to screen the features, obtain the optimal feature subset, and establish the radiomics signature. Four machine learning algorithms, including extreme gradient boosting (XGBoost), logistic, naive Bayes (GNB), and support vector machine (SVM) models, were used to build prediction models for the radiomics signature and the screened clinical independent risk factors. The efficacy of the model in predicting gastric cancer VI was evaluated by the receiver operating characteristic curve. Results:The degree of differentiation (OR=13.651, 95%CI 7.265-25.650, P=0.003), Lauren′s classification (OR=1.349, 95%CI 1.011-1.799, P=0.042) and CA199 (OR=1.796, 95%CI 1.406-2.186, P=0.044) were independent risk factors for predicting the VI of locally advanced gastric cancer. Based on the venous phase enhanced CT images, 864 quantitative features were extracted, and 18 best constructed radiomics signature were selected by LASSO. In the training set, the area under the curve (AUC) of XGBoost, logistic, GNB and SVM models for predicting gastric cancer VI were 0.914 (95%CI 0.875-0.953), 0.897 (95%CI 0.853-0.940), 0.880 (95%CI 0.832-0.928) and 0.814 (95%CI 0.755-0.873), respectively, and in the test set were 0.870 (95%CI 0.769-0.971), 0.877 (95%CI 0.788-0.964), 0.859 (95%CI 0.755-0.961) and 0.773 (95%CI 0.647-0.898). The logistic model had the largest AUC in the test set. Conclusions:The machine learning model based on the venous phase enhanced CT radiomics features has high efficacy in predicting the VI of locally advanced gastric cancer before the operation, and the logistic model demonstrates the best diagnostic efficacy.

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 investigate anticoagulant effects of mechanical methods in obese patients undergoing laparoscopic sleeve gastrectomy (LSG).Methods:In this prospective study, 54 obese patients receiving LSG were enrolled . All patients were given post-op mechanical methods for thrombogenic interventions. BMI and the operation-related factors were recorded. Venous blood specimens were taken from each patient before surgery, at the end of pneumoperitoneum (i.e., 0 h after surgery), at 24 hours after surgery for prothrombin time (PT) and activated partial thromboplastin time (APTT), fibrinogen (FIB) and D-dimer (D-D).Results:All 54 obese patients successfully underwent LSG. No severe complications were observed. Before operation, the mean BMI was (43.49±8.29) kg/m 2. DVT-2600 device was applied in all patients for 3 consecutive days after surgery. The PT values increased at 0 h, 24 h after surgery [(12.4±1.2) s, (12.4±0.8) s vs. (11.2±0.8) s, P=0, 0]. The APTT values at 0 h, 24 h after surgery decreased [(29.7±3.6) s, (29.0±3.1) s vs.(31.2±3.3) s, P=0.020, 0.001]. However, the D-D values increased at 0 h,24 h after operation [(213±143) ng/ml ,(445±237) ng/ml vs. (85±108) ng/ml, P=0, 0]. All patients were followed up for 1 month, and no thrombosis -related complications were observed. Conclusion:Mechanical methods for obese patients after LSG can help decrease the risk of deep venous thrombosis.

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.

Bacitracin is a broad-spectrum antibiotics mainly produced by Bacillus, and is used as veterinary medicine in the fields of livestock and poultry breeding. Insufficient supply of precursor amino acids might be an important factor that hinders high-level microbial production of bacitracin. We investigated the effect of strengthening L-cysteine supply on bacitracin production by an industrial bacitracin producer, Bacillus licheniformis DW2. Overexpression of cysK encoding L-cysteine synthase led to a 9.17% increase of the bacitracin titer. Moreover, overexpression of cysE encoding L-serine acetyltransferase and cysP encoding thiosulfate/sulfate intracellular transporter increased the bacitracin titers by 7.23% and 8.52%, respectively. Moreover, overexpression of a putative cystine importer TcyP led to a 29.19% increase of intracellular L-cysteine, and bacitracin titer was increased by 7.79%. Subsequently, the strong promoter PbacA was used to replace the promoters of genes cysP, cysE and tcyP in strain DW2::ysK, respectively. The resulted strain CYS4 (DW2::cysK-PbacA-(cysP)-PbacA(cysE)- PbacA(tcyP) produced 910.02 U/mL bacitracin, which was 21.10% higher than that of the original strain DW2 (747.71 U/mL). Together with the experiments in 3 L fermenters, this research demonstrated that enhancing intracellular L-cysteine supply is an effective strategy to increase bacitracin production of B. licheniformis.
Amino Acids ; Bacillus licheniformis/genetics* ; Bacitracin ; Cysteine ; Metabolic Engineering