二氧化硅开口剂在流延聚丙烯薄膜中的应用及开口机理

使用4种二氧化硅(SiO_(2))开口剂及一种进口开口剂AB905,通过双螺杆挤出机在相同的加工条件下制备了5种流延聚丙烯膜(CPP)/SiO_(2)母粒并流延成膜。结果表明,5种开口剂都能满足CPP膜的防粘开口性能要求,动/静摩擦系数均降到0.12以内(属于高爽滑性)。50℃,7 kPa负载下压制24 h的抗粘连性测试表明,K45和AB905制成的CPP膜间均没有任何粘连,而纯PP膜有一定的粘连。原子力显微镜分析表明,亚微米级SiO_(2)开口剂粒子附近都存在凹坑,这些凹坑对降低负压、减小范德华力从而降低PP薄膜的粘连起到了非常关键的作用。最后,根据实验数据首次提出了一种适用于CPP膜的防粘连与开口原理模型,有望为生产更高防粘开口效率的开口剂提供参考。

Discrimination of polysorbate 20 by high-performance liquid chromatography-charged aerosol detection and characterization for components by expanding compound database and library

Analyzing polysorbate 20(PS20)composition and the impact of each component on stability and safety is crucial due to formulation variations and individual tolerance.The similar structures and polarities of PS20 components make accurate separation,identification,and quantification challenging.In this work,a high-resolution quantitative method was developed using single-dimensional high-performance liquid chromatography(HPLC)with charged aerosol detection(CAD)to separate 18 key components with multiple esters.The separated components were characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UHPLC-Q-TOF-MS)with an identical gradient as the HPLC-CAD analysis.The polysorbate compound database and library were expanded over 7-time compared to the commercial database.The method investigated differences in PS20 samples from various origins and grades for different dosage forms to evaluate the composition-process relationship.UHPLC-Q-TOF-MS identified 1329 to 1511 compounds in 4 batches of PS20 from different sources.The method observed the impact of 4 degradation conditions on peak components,identifying stable components and their tendencies to change.HPLC-CAD and UHPLC-Q-TOF-MS results provided insights into fingerprint differences,distinguishing quasi products.

A CNN-Based Single-Stage Occlusion Real-Time Target Detection Method

Aiming at the problem of low accuracy of traditional target detection methods for target detection in endoscopes in substation environments, a CNN-based real-time detection method for masked targets is proposed. The method adopts the overall design of backbone network, detection network and algorithmic parameter optimisation method, completes the model training on the self-constructed occlusion target dataset, and adopts the multi-scale perception method for target detection. The HNM algorithm is used to screen positive and negative samples during the training process, and the NMS algorithm is used to post-process the prediction results during the detection process to improve the detection efficiency. After experimental validation, the obtained model has the multi-class average predicted value (mAP) of the dataset. It has general advantages over traditional target detection methods. The detection time of a single target on FDDB dataset is 39 ms, which can meet the need of real-time target detection. In addition, the project team has successfully deployed the method into substations and put it into use in many places in Beijing, which is important for achieving the anomaly of occlusion target detection.

巴基斯坦大学生汉语学习策略研究

以Oxford语言学习策略调查量表为测量工具,调查了巴基斯坦国立现代语言大学中文系245名学生的汉语学习策略,发现非目的语环境下的巴基斯坦大学生对各种学习策略的运用都达到高频度范围。巴基斯坦大学生汉语学习策略存在显著的年龄、学期、职业、学习强度和教育背景上的组间差异,而元认知策略、社交策略、认知策略和情感策略在学期和学习强度方面存在显著的交互作用。

Whole-genome Sequencing Reveals Autooctoploidy in Chinese Sturgeon and Its Evolutionary Trajectories

The order Acipenseriformes,which includes sturgeons and paddlefishes,represents“living fossils”with complex genomes that are good models for understanding whole-genome duplication(WGD)and ploidy evolution in fishes.Here,we sequenced and assembled the first high-quality chromosome-level genome for the complex octoploid Acipenser sinensis(Chinese sturgeon),a critically endangered species that also represents a poorly understood ploidy group in Acipenseriformes.Our results show that A.sinensis is a complex autooctoploid species containing four kinds of octovalents(8n),a hexavalent(6n),two tetravalents(4n),and a divalent(2n).An analysis taking into account delayed rediploidization reveals that the octoploid genome composition of Chinese sturgeon results from two rounds of homologous WGDs,and further provides insights into the timing of its ploidy evolution.This study provides the first octoploid genome resource of Acipenseriformes for understanding ploidy compositions and evolutionary trajectories of polyploid fishes.

Surgical complexity and prognostic outcome of small volume renal cell carcinoma with high-level venous tumor thrombus and large volume renal cell carcinoma with low-level thrombus

Background:Radical nephrectomy with thrombectomy is one of the most difficult and complicated urological operations.But the roles of renal tumor volume and thrombus level in surgical complexity and prognostic outcome are not clear.This study aimed to evaluate the surgical complexity and prognostic outcome between the volume of renal cell carcinoma (RCC) and the level of venous tumor thrombus.Methods:The clinical data of 67 RCC cases with renal vein or inferior vena cava (IVC) tumor thrombus from January 2015 to May 2018 were retrospectively analyzed.Among these 67 cases,21 (31.3%) were small tumors with high-level thrombus (tumor ≤7 cm in diameter and thrombus Neves Level Ⅱ-Ⅳ),while 46 (68.7%) were large tumors with low-level thrombus group (tumor >7 cm in diameter and thrombus Level 0-Ⅰ).Clinical features,operation details,and pathology data were collected.Univariable and multivariable logistic regression analyses were applied to evaluate the risk factors for small tumor with high-level thrombus.Results:Patients with small tumors and high-level thrombus were more likely to have longer operative time (421.9 ± 135.1 min vs.282.2 ± 101.9 min,t=4.685,P < 0.001),more surgical bleeding volume (1200 [325,2900] mL vs.500 [180,1000] mL,U =270.000,P =0.004),more surgical blood transfusion volume (800 [0,1400] mL vs.0 [0,800] mL,U =287.500,P =0.004),more plasma transfusion volume (0 [0,800] mL vs.0 [0,0] mL,U =319.000,P =0.004),higher percentage of open operative approach (76.2% vs.32.6%,x2 =11.015,P =0.001),higher percentage of IVC resection (33.3% vs.0%,x2 =17.122,P < 0.001),and higher percentage of post-operative complications (52.4% vs.19.6%,x2 =7.415,P =0.010) than patients with large tumors and low-level thrombus.In multivariate analysis,decreased hemoglobin (Hb)(odds ratio [OR]:0.956,95 % confidence interval [CI]:0.926-0.986,P =0.005) and non-sarcomatoid differentiation (OR:0.050,95% CI:0.004-0.664,P =0.023) were more likely to form small tumors with high-level tumor thrombus rather than large tumor with small tumor thrombus.The estimated mean cancerspecific survival times of small tumor with high-level thrombus and large tumor with low-level thrombus were 31.6 ± 3.8 months and 32.5 ± 2.9 months,without statistical significance (P =0.955).After univariate and multivariate Cox proportional hazard survival regression analyses,only distant metastasis (hazard ratio [HR]:3.839,P =0.002),sarcomatoid differentiation (HR:7.923,P < 0.001),alkaline phosphatase (HR:2.661,P =0.025),and severe post-operative complications (HR:10.326,P =0.001) were independent predictors of prognosis.Conclusions:The level of the tumor thrombus was more important than the diameter of the primary kidney tumor in affecting the complexity of surgery.In the same T3 stage,neither the renal tumor diameter nor the tumor thrombus level was an independent risk factor for prognosis.

Peking University Third Hospital score:a comprehensive system to predict intra-operative blood loss in radical nephrectomy and thrombectomy

Background:Radical nephrectomy and thrombectomy is the standard surgical procedure for the treatment of renal cell carcinoma (RCC) with tumor thrombus (TT). But the estimation of intra-operative blood loss is only based on the surgeon’s experience. Therefore, our study aimed to develop Peking University Third Hospital score (PKUTH score) for the prediction of intra-operative blood loss volume in radical nephrectomy and thrombectomy.Methods: The clinical data of 153 cases of renal mass with renal vein (RV) or inferior vena cava tumor thrombus admitted to Department of Urology, Peking University Third Hospital from January 2015 to May 2018 were retrospectively analyzed. The total amount of blood loss during operation is equal to the amount of blood sucked out by the aspirator plus the amount of blood in the blood-soaked gauze. Univariate linear analysis was used to analyze risk factors for intra-operative blood loss, then significant factors were included in subsequent multivariable linear regression analysis.Results: The final multivariable model included the following three factors: open operative approach (P < 0.001), Neves classification IV (P < 0.001), inferior vena cava resection (P = 0.001). The PKUTH score (0-3) was calculated according to the number of aforementioned risk factors. A significant increase of blood loss was noticed along with higher risk score. The estimated median blood loss from PKUTH score 0 to 3 was 280 mL (interquartile range [IQR] 100-600 mL), 1250 mL (IQR 575-2700 mL), 2000 mL (IQR 1250-2900 mL), and 5000 mL (IQR 4250-8000 mL), respectively. Meanwhile, the higher PKUTH score was, the more chance of post-operative complications (P = 0.004) occurred. A tendency but not significant overall survival difference was found between PKUTH risk score 0vs. 1 to 3 (P = 0.098).Conclusion: We present a structured and quantitative scoring system, PKUTH score, to predict intra-operative blood loss volume in radical nephrectomy and thrombectomy.

Two-dimensional porous zinc cobalt sulfide nanosheet arrays with superior electrochemical performance for supercapatteries

Unique two-dimensional(2D)porous nanosheets with overwhelmingly rich channels and large specific surface area exhibit superior electrochemical capacitance performance,as compared to the conventional zero-and one-dimensional counterparts.As ternary transition metal sulfides(TMSs)are well recognized for their high electrochemical activity and capacity,and the replacement of oxygen with sulfur may result in high stability and flexible properties of the nanomaterials,as compared to transition metal oxides,herein we report the synthesis of 2D porous nanosheet arrays of Zn_(x)Co_(1-x)S(x=0,0.25,0.5,0.75,and 1)via a facile hydrothermal process.Due to the synergistic effect of the metal components and a unique 2D porous structure,the Zn_(0.5)Co_(0.5)S electrode was found to stand out as the best among the series,with a high specific capacity of 614 C g^(-1)at 1 A g^(-1)and excellent cycle retention rate of 90%over 10,000 cycles at 10 A g^(-1).Notably,a supercapattery based on a Zn_(0.5)Co_(0.5)S positive electrode and an activated carbon(AC)negative electrode(Zn_(0.5)Co_(0.5)S//AC)was found to display a 1.6 V voltage window,a 61 mA h g^(-1)specific capacity at 1 A g^(-1),a 49 Wh kg^(-1)energy density at 957 W kg^(-1)power density,and excellent cycling performance(88%over 10,000 cycles),suggesting tremendous potential of Zn_(0.5)Co_(0.5)S in the development of high-performance supercapattery devices.