课堂上的“节外生枝”

一道难度不大的例题在课堂上引起热烈的讨论,经过进一步的探究得到许多意外收获.教师必须认真研究教材,真正做到“用教材教”,才能最终达到提高课堂教学实效和学生综合能力的效果.课堂上的“节外生枝”正是学生智慧的火花,是提升学生数学核心素养的载体.如果我们的课堂多一些“节外生枝”,或许会成就一番课堂上的别样精彩.

解锐角三角形的特殊性问题研究

各类考试中经常出现解锐角三角形问题,有的同学因为忽略了锐角三角形的特殊性而功亏一篑!结合实例,对解锐角三角形的特殊性问题进行研究.

立体几何到底考什么

对于立体几何的学习,一直存在一种过分依赖坐标法的现象,立体几何考的是学生的数学核心素养.立体几何的教学中要注重培养学生的直观想象、逻辑推理、数学运算等核心素养,扎扎实实练好基本功,以不变应万变.

Electric-driven flexible-roller nanoimprint lithography on the stress-sensitive warped wafer

Surface nanopatterning of semiconductor optoelectronic devices is a powerful way to improve their quality and performance.However,photoelectric devices’inherent stress sensitivity and inevitable warpage pose a huge challenge on fabricating nanostructures large-scale.Electric-driven flexible-roller nanoimprint lithography for nanopatterning the optoelectronic wafer is proposed in this study.The flexible nanoimprint template twining around a roller is continuously released and recovered,controlled by the roller’s simple motion.The electric field applied to the template and substrate provides the driving force.The contact line of the template and the substrate gradually moves with the roller to enable scanning and adapting to the entire warped substrate,under the electric field.In addition,the driving force generated from electric field is applied to the surface of substrate,so that the substrate is free from external pressure.Furthermore,liquid resist completely fills in microcavities on the template by powerful electric field force,to ensure the fidelity of the nanostructures.The proposed nanoimprint technology is validated on the prototype.Finally,nano-grating structures are fabricated on a gallium nitride light-emitting diode chip adopting the solution,achieving polarization of the light source.

Single-Cell RNA Sequencing Reveals Potential for Endothelial-to-Mesenchymal Transition in Tetralogy of Fallot

Background:Tetralogy of Fallot(TOF)is a very common cyanotic congenital heart disease.Endothelial-to-mesenchymal transition(EndoMT)is recognized as a physiological mechanism involved in embryonic heart development and endothelial formation.However,there is still a gap in the reports related to the mechanism of EndoMT development in TOF.Methods:First,transcriptomic data of single cell nuclei of TOF and Donor were obtained based on the Gene Expression Omnibus(GEO)database,and the data were normalized and clus-tered by dimensionality reduction using the Seurat package.Subsequently,differentially expressed genes(DEGs)between TOF and Donor were screened using the“FindMarkers”function,and the gene sets of interest were enriched.Finally,to characterize the dynamics of EndoMT occurrence in TOF,we performed pseudotime cell tra-jectory inference as well as utilized SCENIC analysis to probe the gene regulatory networks(GRNs)dominated by transcription factors(TFs)in endothelial cells.Results:We identified a total of six cell clusters based on single-cell nuclear transcriptome data from TOF and Donor.We found that 611 genes with up-regulated expression within TOF showed conversion to mesenchyme.By subdividing endothelial cell subtypes,endothelial cells 2 were shown to be involved in cell adhesion,migration and extracellular matrix processes.Pseudo-time and SCENIC analyses showed that endothelial cell 2 has EndoMT potential.In addition,ERG and TEAD1 are TFs that play key reg-ulatory roles in this subtype,and both of their target genes are also highly expressed in TOF.This demonstrates that ERG and TEAD1 effectively promote the EndoMT process.Conclusion:Our study reveals the molecular mechanisms underlying the development of EndoMT in TOF,which demonstrates that manipulating the endothelial-to-mesenchymal transition may offer unprecedented therapeutic potential for the treatment of TOF.

Application of a jigsaw puzzle flap based on free-style perforator to repair large scalp defects after tumor resection:A case series

Background:Reconstruction of large scalp defects after tumor resection is common and challenging.Free skin grafting or free flap transfer is always performed.However,these techniques can result in poor functional and cosmetic outcomes.Methods:In the Second Affiliated Hospital of Soochow University and the Second Affiliated Hospital of Chengdu Medical College,35 patients underwent jigsaw puzzle flap procedures based on a free-style perforator to repair large scalp defects after tumor resection from May 2013 to November 2022.The key to this procedure was to divide a large defect into several smaller parts that correspond to adjacent free-style perforators around the scalp defect.The free-style perforator flaps were designed in different ways,such as propeller flaps,rotation flaps,and V-Y advancement flaps,which were pedicled with free-style perforators.All of the small flaps were then mobilized to the defect and sutured to each other to create a new,large jigsaw puzzle-like flap to cover the large scalp defect.Finally,all the donor sites were closed directly.Results:Overall,35 patients were treated.The average defect size was 72 cm^(2)(range,25-91 cm^(2)).All flaps had a satisfactory appearance after follow-up periods of 6 months-10 years.Local tumor recurrence occurred in one case.Conclusion:The application of a jigsaw puzzle flap based on a free-style perforator is a suitable option for the reconstruction of large scalp defects after resection,yielding satisfactory functional and cosmetic results.

Study on Optimization of Polymer Enhanced Foam Formulation System

Taking the pilot test area of polymer enhanced foam flooding in Y oilfield as the prototype, a numerical core model was established, and the polymer enhanced foam formulation system was optimized by analyzing the resistance factor and the change rule of oil recovery of different formulation systems. Research shows that the higher the polymer concentration, the greater the resistance factor, and the more obvious the sealing effect formed in the formation. The concentration of surfactant has a greater impact on the resistance factor. With the increase of surfactant concentration, the resistance factor increases significantly, and the plugging effect of foam agent on core is significantly enhanced. With the increase of gas-liquid ratio, the resistance factor first increases and then decreases. When the gas-liquid ratio is 1:1, the resistance is the largest, and the foam agent has the strongest plugging effect on the core. The optimal formula system of polymer enhanced foam flooding in Y oilfield is: polymer concentration is 1200 mg/L, surfactant concentration is 0.25 wt%, gas-liquid ratio is 1:1.

例谈数学直观想象素养的提升

数学核心素养主要由数学抽象、逻辑推理、数学建模、直观想象、数学运算、数据分析等六个方面组成.仅就其中的直观想象素养,结合具体的教学案例,谈谈如何在课堂教学中去进行提升.在高中数学的学习中,有许多内容适合作为提升学生直观想象核心素养的载体.数学核心素养应该渗透在具体教学内容的教学过程中,成为引导学生理解和应用数学知识的指路明灯.

对一道联考试题的探究

一道看似简单的联考试题几乎令所有学生“崩溃”.解题思路形成、汇聚和选择的过程,就是智力活动养成习惯的过程,也是数学核心素养的重要生长点.此题很好地考查了学生的数学抽象、逻辑推理、直观想象、数学运算、数学建模等核心素养.从考试区分度的角度看,此题存在弊端.

复合函数含参问题研究

复合函数含参问题时常悄然出现在高考及各级各类模考的舞台.由于复合函数的多样性及含参问题的复杂性,对学生的思维能力、逻辑推理能力、运算能力等要求较高.通过实例对此类问题进行研究,以求掌握解决此类问题的一些策略和方法,从而更好备考.

局部热消融在NSCLC中的临床应用现状与挑战

非小细胞肺癌(non-small cell lung cancer, NSCLC)是原发性肺癌的主要类型,手术切除、放化疗、靶向治疗及免疫治疗等是其主要的治疗模式。近年来,热消融在各期NSCLC的临床应用中受到越来越多的关注。热消融作为一种安全、高效的局部治疗手段,合理的临床应用可以给NSCLC患者带来更多的临床获益。然而其在NSCLC中的应用仍然存在许多尚待研究探讨的问题。本文对近年来热消融在NSCLC中的应用现状作以综述,旨在探讨目前存在的争议问题和未来研究方向。

6G蜂窝物联网的大规模接入技术

为了实现万物互联,6G蜂窝物联网需要提供低功耗、巨连接和广覆盖的无线接入。通过对6G物联网中大规模接入技术的分析和研究,特别是结合物联网业务的偶发特性,设计了一个基于免授权随机接入协议的新型接入架构,以促进在有限频谱资源内实现高效的大规模接入。所提接入架构包括两个阶段,即联合激活检测与信道估计、数据传输。根据数据传输方向的不同,可以分为上行数据传输和下行数据传输两种方案。由于大规模免授权随机接入情况下基站获取的信道信息具有不确定性,同时考虑6G物联网设备的低功耗需求,因此,两种方案都以系统能量效率为优化目标,分别设计了稳健的接入算法。仿真结果证明了所提方案的有效性和稳健性。

Relationship between circulating tumor cells undergoing EMT and short-term efficacy following interventional treatment in patients with hepatocellular carcinoma

Objective:A growing number of studies have indicated that epithelial-mesenchymal transition(EMT)phenotypes and the number of circulating tumor cells(CTCs)are significant indicators of tumor characteristics and treatment efficacy,and thus have a broad range of potential applications in the diagnosis and treatment of malignant tumors.The value of data on CTC phenotypes and CTC counts in the diagnosis of hepatocellular carcinoma(HCC)and assessment of efficacy after comprehensive interventional therapy remains unclear.Methods:Data of 107 patients who exhibited space-occupying lesions in the liver on enhanced CT/MRI scans at the Guangdong Provincial People’s Hospital(a tertiary medical center)between August 2017 and October 2018,were retrospectively analyzed.All enrolled patients were treated with transcatheter arterial chemoembolization(TACE)combined with microwave ablation(MWA).An imFISH CTC assay was used to isolate and count CTCs with different EMT phenotypes in the patients’peripheral blood,which facilitated an analysis of the value of CTC phenotype and CTC count data in the diagnosis or treatment of HCC.Results:The CTC count and EMT phenotypes in HCC patients were not associated with patient characteristics such as age,sex,Hepatitis B Virus(HBV)-DNA status,alcohol consumption history,Aspartate Transaminase(AST)to Platelet Ratio Index(APRI)score,Eastern Cooperative Oncology Group(ECOG)score,Child-Pugh score,alphafetoprotein(AFP),number and size of tumors,vascular invasion,or metastasis(P>0.05).The CTC count and EMT phenotypes in HCC patients before treatment were not predictive of short-term efficacy(P>0.05).Comprehensive interventional therapy reduced the total CTC count and mesenchymal CTC count(P?0.034 and0.022,respectively).Conclusion:TACE in combination with ablation reduced the total CTC count and mesenchymal CTC count.The CTC count and EMT phenotypes may be associated with long-term efficacy.

A New Method for Calculating Similarity between Sentences and Application on Automatic Abstracting

Sentence similarity computing plays an important role in machine question-answering systems, machine-translation systems, information retrieval and automatic abstracting systems. This article firstly sums up several methods for calculating similarity between sentences, and brings out a new method which takes all factors into consideration including critical words, semantic information, sentential form and sen-tence length. And on this basis, a automatic abstracting system based on LexRank algorithm is implemented. We made several improvements in both sentence weight computing and redundancy resolution. The system described in this article could deal with single or multi-document summarization both in English and Chinese. With evaluations on two corpuses, our system could produce better summaries to a certain degree. We also show that our system is quite insensitive to the noise in the data that may result from an imperfect topical clustering of documents. And in the end, existing problem and the developing trend of automatic summariza-tion technology are discussed.

Characterization and Antioxidant Properties of OJP2, a Polysaccharide Isolated from <i>Ophiopogon japonicus</i>

A water-soluble polysaccharide (OJP2) obtained from the roots of Ophiopogon japonicas, was precipitated with 95% ethanol and purified by DEAE-52 cellulose anion-exchange and Sephadex G-100 gel filtration chromatography. The characteristics of OJP2 were determined by chemical analysis, high performance gel permeation chromatography (HPGPC), and gas chromatography-mass spectrometry (GC-MS). The results showed that the average molecular weight (Mw) of OJP2 was 35.2 kDa, and five kinds of monosaccharides including rhamnose, arabinose, xylose, glucose and galactose in a molar ratio of 0.5:5:4:1:10. Furthermore, the antioxidant activity of OJP2 was evaluated in H2O2-treated HaCaT cells and glucose-treated LO2 cells. The results show that OJP2 can increase the activity of SOD and NO production, and decrease the level of MDA in these two kinds of injury cells. OJP2 should be explored as a novel and potential natural antioxidant agent for use in functional foods or medicine.

对“双曲线的渐近线”的研究性学习

对教材中的一些教学难点进行研究性学习,表面上看是“耽误时间”,实则让学生不仅消化了知识,更重要的是发展了能力、培育了理性精神、提高了数学素养,从长远来看对学生是有利的.以双曲线的渐近线为例来说明问题.

Photosynthetic traits and antioxidative defense responses of Pinus yunnanensis after joint attack by bark beetles Tomicus yunnanensis and T.minor

Bark beetles Tomicus yunnanensis and T.minor are two important pests of Pinus yunnanensis and can cause massive death of pine trees.In this study,we examined several traits related to photosynthesis in P.yunnanensis and their relationship with antibiotic defense responses after joint attack by the two bark beetles at the shoot and the trunk stages.When shoots were attacked by the beetles,the abundance of chlorophylls,carotenoids,and the rates of net photosynthesis(Pn)and transpiration(E)decreased in needles,while the levels of superoxide dismutase and malondialdehyde remained unchanged in both needles and phloem.The activity of peroxidases also remained unchanged in needles,but increased in phloem.The activity of catalases increased in both needles and phloem.When trunks were attacked by the bark beetles,chlorophyll abundance,Pn,E,and antioxidative enzyme activities all declined,and the declines were more pronounced than in the attacked shoots.A decrease in protein concentrations was also observed in needles and phloem from the attacked pines.Attack on shoots by the bark beetles suppressed host defense and provided a favorable environment for larval growth and development,resulting in long-term decline of pine growth potential.The results suggest that attacks on trunks by beetles caused more severe damage to host trees than attacks on shoots.

Clinical review considerations of class I PI3K inhibitors in hematolymphatic malignancies by Center for Drug Evaluation

Several phosphoinositide 3-kinase(PI3 K) inhibitors are currently approved to treat hematolymphatic malignant diseases worldwide, and many drugs that have the same target are in the clinical research stage. In March 2022,duvelisib became the first PI3 K inhibitor approved in China indicated for the treatment of hematolymphatic malignant diseases. Meanwhile, linperlisib and copanlisib have almost completed the technical review of the clinical specialty. The Center for Drug Evaluation(CDE) of the China National Medical Products Administration(NMPA) found that class I PI3 K inhibitors can cause various degrees of immune-related adverse events, which are associated with action mechanisms, affecting the benefit-risk assessment of the drugs. On April 21, 2021, the United States Food and Drug Administration(FDA) convened the Oncologic Drugs Advisory Committee(ODAC)meeting to discuss the safety of PI3 K inhibitors indicated for hematolymphatic malignancies and their related risk of death. The hematological tumor group of CDE of the China NMPA summarized and combined the data on PI3 K inhibitors listed or under technical review for marketing authorization applications and found that such products may have unique efficacy and safety characteristics in Chinese patients with malignant lymphoma.

Acute toxicity and chromosomal aberration toxicity of insect wax and its policosanol

An acute toxicity test in Sprague Dawley(SD)rats and a chromosomal aberration toxicity test in Chinese hamster lung(CHL)fibroblasts were conducted to promote the application of insect wax and its policosanol.Results of oral acute toxicity test showed that the LD;values of insect wax and its policosanol were higher than 5000 mg/kg.The rats showed no obvious toxic symptoms and survived,suggesting that these substances were not toxic.The chromosomal aberration rates of the CHL cells incubated with insect wax for 3-6 h under metabolic activation conditions and for 3-6 h and 24 h under non-metabolic activation conditions were lower than 5%.No significant difference was found compared with the negative control group.Also,no significant difference in chromosomal aberration rates was found between each dose group of policosanol under metabolic or non-metabolic activation conditions and the negative control group.Therefore,the chromosomal aberration rates of CHL cells treated with insect wax and its policosanol were negative regardless of metabolic activation conditions.These results indicate the absence of acute toxicity and potential chromosomal aberration in the tested dose range of insect wax and its policosanol.

Discharge Distribution and Quality of Tail Water for Mariculture in Tianjin

[Objectives] This study was conducted to understand the pollution load of mariculture in Tianjin. [Methods] The tail water discharged by the main mariculture methods in Tianjin was monitored, and the tail water quality was evaluated. According to the aquaculture area and distribution and the discharge destination of the aquaculture tail water, a preliminary evaluation of the pollutant discharge situation was carried out, and different aquaculture methods were compared and analyzed for the differences in discharged pollutants. [Results] The main pollution factors in pond mariculture were chemical oxygen demand(CODMn), active phosphate and total phosphorus. The main pollution factors in factory mariculture were inorganic nitrogen, active phosphate and total nitrogen. Pond mariculture showed higher up-to-standard rates of inorganic nitrogen and active phosphate contents and lower up-to-standard rates of suspended solids, CODMn, and total phosphorus content than factory mariculture, and the up-to-standard rates of total nitrogen and total phosphorus contents in the flowing water type of factory mariculture were higher than those in the circulating water type. The discharge of pond mariculture was less than factory mariculture, and mariculture had the greatest impact on Fuzhuang Drainage Canal in that 92.3% of the total pollutant discharge monitored went to Fuzhuang Drainage Canal. The circulating water type could reduce pollutant discharge compared with the flowing water type of factory mariculture. [Conclusions] This study proposed countermeasures and suggestions for reducing pollution from marineculture.