累及大血管的腹膜后肿瘤处理策略探讨

腹膜后肿瘤(retroperitoneal tumor,RPT)发病较为隐匿,出现症状时肿瘤往往体积较大,多侵犯周围组织与脏器,尤其是腹腔重要血管,是RPT手术主要难点。累及大血管RPT的处理常被很多外科医生视为禁区,但手术仍是目前治疗该病唯一有效的方法,累及大血管RPT的处理决策是提高肿瘤手术切除率的关键。因此,术前对肿瘤累及血管程度的评估,术中对血管重建技术的应用对于肿瘤完整切除至关重要。术前应用影像学检查了解RPT与腹腔大血管之间的关系、浸润情况,手术中良好的术野为处理和控制血管出血创造了有利条件;累及大血管RPT在完整切除时,需要对一些重要的血管进行修复与重建,自体血管的使用技术已日益成熟,人工血管和补片的应用也为手术创造了条件。术前评估、手术策略、术后管理对肿瘤外科医生在累及大血管RPT的患者治疗过程中起着至关重要的作用。

Optimal interventional treatment for liver cancer:HAIC,TACE or iTACE?

Primary liver cancer is a common and lethal malignancy in China.Transcatheter arterial chemoembolization(TACE)is globally recognized as the preferred treatment modality for the non-surgical resection of hepatocellular carcinoma(HCC),while transcatheter arterial infusion(TAI)is another effective interventional treatment for HCC.In recent years,hepatic arterial infusion chemotherapy(HAIC)has gained increasing attention as an application-regulated modality for TAI.Owing to the current debate in the medical community regarding the use of HAIC and TACE for the treatment of HCC,the application of both approaches should be considered at a higher level,with a broader perspective and a more normative aspect.Accordingly,we aimed to define the rational combination of liver cancer TAI/HAIC with TACE as infusion transcatheter chemoembolization(iTACE),which suggests that the two interventions are not superior but lead to a mutually beneficial situation.In this review,we sought to discuss the development,specification,application,challenge and innovation,debate,and union of TAI/HAIC and TACE,and the clinical application and latest research on iTACE.We aimed to introduce new concepts of iTACE and expect new breakthroughs in the treatment of liver cancer owing to the combined use of the two major interventional tools.

Large eddy simulation of supersonic flow in ducts with complex cross-sections

Large Eddy Simulation(LES)has been employed for the investigation of supersonic flow characteristics in five ducts with varying cross-sectional geometries.The numerical results reveal that flow channel configurations exert a considerable influence on the mainstream flow and the near-wall flow behavior.In contrast to straight ducts,square-to-circular and rectangular-to-circular ducts exhibit thicker boundary layers and a greater presence of vortex structures.Given the same inlet area,rectangular-to-circular ducts lead to higher flow drag force and total pressure loss than square-to-circular ducts.Characterized by the substantial flow separation and shock waves,the"S-shaped duct shows significant vertically-asymmetric characteristics.

Application of Optical Visualization Method in Observing Flow Field Around a Cylinder

In this paper, a free-surface synthetic schlieren(FS-SS) method was performed to detect the free surface disturbances. It is a purely optical method that uses refraction of light to reconstruct the height changes of water surface. The theory was developed based on Moisy's research, but has mainly been used in small-scale applications like painting and coating industry. Based on the methods and theories of the literature review, an in-depth investigation was conducted to optimize the FS-SS method and verify its feasibility on a relatively large-scale(e.g., wake region of shallow flow). The experimental setup was simplified which is approachable in most laboratories. Through proper experimental setting and an optimized post-processing routine, the quality of image was highly improved and ensured the accuracy of results. A drop test was performed proving the continuity of FS-SS method in the time domain. Also, a comparison test with flow around a cylinder at two speeds showed the ability of FS-SS method to reconstruct the irregular water surface in relative large-scale flow structures.

进展期胃癌术后腹腔热灌注化疗的研究进展

胃癌为临床常见恶性肿瘤之一,外科手术是其重要治疗方案,进展期胃癌患者术后5年生存率较低,而术后癌灶复发成为影响患者预后的重要因素。随着国内医学水平不断发展,腹腔热灌注化疗技术得以不断改进,其在进展期胃癌患者术后辅助治疗中的应用日益广泛,长期临床实践表明预防性运用腹腔热灌注化疗可明显降低进展期胃癌术后复发率并提高其5年生存率,在改善患者生存质量及总体临床疗效方面的作用明确。本文旨在对中国进展期胃癌术后腹腔热灌注化疗的临床应用进展进行综述。

基于MRI-病理对照的动态增强磁共振成像定量参数评估骨肉瘤新辅助化疗肿瘤坏死率的价值

目的:基于MRI-病理对照,探讨动态增强磁共振成像(dynamic contrast-enhanced magnetic resonance imaging,DCE-MRI)定量参数评估骨肉瘤新辅助化疗(neoadjuvant chemotherapy,NAC)肿瘤坏死率的价值。方法:收集2019年1月至2020年6月于昆明医科大学第三附属医院收治的膝关节周围骨肉瘤患者11例,于NAC前、后行常规MRI及矢状位DCE-MRI检查。NAC疗程结束后两周内经外科手术获取完整肿瘤瘤段,沿正中矢状面剖开,取厚度为5 mm病理切片并分割成大小为1 cm×1 cm的若干组织块,编号后作为与影像对照的病理样本。依靠解剖标志,确定与病理切片对应的DCE-MRI影像层面,将病灶划分为1 cm×1 cm大小感兴趣区(region of interest,ROI),并进行化疗前、后影像ROI与病理样本匹配。采用Omni Kinetics软件测量化疗前定量参数-pre-K^(trans)、pre-K_(ep)、pre-Ve、pre-Vp和化疗后参数-post-K^(trans)、post-K_(ep)、post-V_(e)、post-V_(p),并计算化疗前-后各参数差值∆K^(trans)、∆K_(ep)、∆V_(e)、∆V_(p)。采用Huvos分级标准检测每个病理样本肿瘤坏死率(tumor necrosis rate,TNR),并划分为缓解组(TNR≥90%)和未缓解组(TNR<90%)。采用Mann-Whitney U检验,比较两组病理样本NAC前、后各定量参数是否存在差异。采用ROC曲线,比较NAC后DCE-MRI定量参数及治疗前后的差值预测NAC后TNR的效能。结果:入组骨肉瘤11例,共取得304个病理样本,其中缓解组59个(19.4%),未缓解组245个(80.6%)。两组化疗后K^(trans)、V_(e)、V_(p)均明显降低,且未缓解组参数值明显低于缓解组(P<0.05);化疗后缓解组K_(ep)明显升高(P<0.05),但未缓解组K_(ep)无差异(P>0.05)。两组化疗前后参数差值ΔK^(trans)、ΔV_(e)、ΔV_(p)差异无统计学意义(P>0.05),但缓解组ΔK_(ep)明显低于未缓解组(P<0.05)。ROC曲线分析结果,化疗后定量参数诊断TNR缓解效能优于化疗前-后差值,其中post-K^(trans)诊断效能最高,诊断阈值为0.663/min、AUC为0.745、灵敏度为89.83%、特异性为52.24%。结论:DCE-MRI定量参数在评估骨肉瘤新辅助化疗TNR有一定的应用价值,具有即时、无创反映NAC疗效的应用潜力。

明胶-海藻酸钠制备薄荷油微胶囊的工艺优化

文中对以明胶和海藻酸钠为壁材,薄荷油为芯材用复凝聚法制备微胶囊的工艺进行了优化,通过对2种壁材复凝聚行为和微胶囊化工艺参数的优化,得到了最佳制备工艺:复凝聚pH值为4.3,明胶与海藻酸钠的质量比为4∶1,乳化剂体积分数为0.5%,均质时间为9 min,壁材浓度1.75%,复凝聚速度为600 r/min。经过优化后的微胶囊形态良好,为完整规则的圆球形,壁材对芯材包埋良好,产率为85.64%,含油率为50.00%,壁材利用率为78.75%,经热重(TG)测试表明,相比150℃以内就能完全损失的纯薄荷油,制得的薄荷油微胶囊在250℃以下可在外壳的保护作用下使内部薄荷油达到缓慢释放,从而赋予薄荷油良好的热稳定性。

丙烯酸原位聚合改性纤维素纳米晶体/聚乙烯醇复合膜的制备及性能

利用丙烯酸原位聚合和纤维素纳米晶体与聚乙烯醇复合制备聚乙烯醇-聚丙烯酸-纤维素纳米晶体(PVA-(PAACNC))复合膜。通过傅里叶变换红外光谱、扫描电子显微镜分析、接触角测试、拉伸试验和透光率测试考察了CNC和PAA的共同添加对复合膜结构形态、耐水性、力学性能和透明性的影响。结果表明,与纯PVA膜相比,改性复合膜仍然保持较高的透光率,在可见光低波段最低只降低5.6%;表面疏水性得到改善,接触角提高了40°以上;只用CNC改性时,所得的PVA-CNC复合膜中CNC的团聚现象比较严重,且力学性能对环境湿度非常敏感;同时用PAA和CNC改性时,所得复合膜中CNC的团聚现象得到明显抑制,在100RH%湿态环境下仍保持较好的力学性能,且断裂伸长率大幅提高。

Protective effect of oxysophoridine on cerebral ischemia/reperfusion injury in mice

Oxysophoridine, a new alkaloid extracted from Sophora alopecuroides L., has been shown to have a protective effect against ischemic brain damage. In this study, a focal cerebral ischemia/reperfusion injury model was established using middle cerebral artery occlusion in mice. Both 62.5, 125, and 250 mg/kg oxysophoridine, via intraperitoneal injection, and 6 mg/kg nimodipine, via intragastric administration, were administered daily for 7 days before modeling. After 24 hours of reperfusion, mice were tested for neurological deficit, cerebral infarct size was assessed and brain tissue was collected. Results showed that oxysophoridine at 125, 250 mg/kg and 6 mg/kg nimodipine could reduce neurological deficit scores, cerebral infarct size and brain water content in mice. These results provided evidence that oxysophoridine plays a protective role in cerebral ischemia/reperfusion injury. In addition, oxysophoridine at 62.5, 125, and 250 mg/kg and 6 mg/kg nimodipine increased adenosine-triphosphate content, and decreased malondialdehyde and nitric oxide content. These compounds enhanced the activities of glutathione-peroxidase, superoxide dismutase, catalase, and lactate dehydrogenase, and decreased the activity of nitric oxide synthase Protein and mRNA expression levels of N-methyI-D-aspartate receptor subunit NR1 were markedly inhibited in the presence of 250 mg/kg oxysophoridine and 6 mg/kg nimodipine. Our experimental findings indicated that oxysophoridine has a neuroprotective effect against cerebral ischemia/reperfusion injury in mice, and that the effect may be due to its ability to inhibit oxidative stress and expression of the N-methyI-D-aspartate receptor subunit NR1.

High-Efficiency Wastewater Purification System Based on Coupled Photoelectric–Catalytic Action Provided by Triboelectric Nanogenerator

It is of great importance to explore a creative route to improve the degradation e ciency of organic pollutants in wastewater.Herein,we construct a unique hybrid system by combining self-powered triboelectric nanogenerator(TENG)with carbon dots-TiO_(2)sheets doped three-dimensional graphene oxide photocatalyst(3 DGA@CDs-TNs),which can significantly enhance the degradation e ciency of brilliant green(BG)and direct blue 5 B(DB)owing to the powerful interaction of TENG and 3 DGA@CDs-TNs photocatalyst.The power output of TENG can be applied for wastewater purification directly,which exhibits a selfpowered electrocatalytic technology.Furthermore,the results also verify that TENG can replace conventional electric catalyst to remove pollutants e ectively from wastewater without any consumption.Subsequently,the unstable fragments and the plausible removal pathways of the two pollutants are proposed.Our work sheds light on the development of e cient and sustainable TENG/photocatalyst system,opening up new opportunities and possibilities for comprehensive utilization of random energy.

Oxygen Vacancy-induced Electron Density Tuning of Fe_(3)O_(4) for Enhanced Oxygen Evolution Catalysis

Despite the tremendous efforts devoted to enhancing the activity of oxygen evolution reaction(OER)catalysts,there is still a huge challenge to deeply understand the electronic structure characteristics of transition metal oxide to guide the design of more active catalysts.Herein,Fe_(3)O_(4)with oxygen vacancies(Fe_(3)O_(4)-Vac)was synthesized via Ar ion irradiation method and its OER activity was greatly improved by properly modulating the electron density around Fe atoms.The electron density of Fe_(3)O_(4)-Vac around Fe atoms increased compared to that of Fe_(3)O_(4)according to the characterization of synchrotron-based X-ray absorption near-edge structure(XANES),extended X-ray absorption fine structure(EXAFS)spectra,and density functional theory(DFT)calculation.Moreover,the DFT results indicate the enhancement of the desorption of HOO^(*)groups which significantly reduced the OER reaction barrier.Fe_(3)O_(4)-Vac catalyst shows an overpotential of 353 m V,lower than that of Fe OOH(853 m V)and Fe_(3)O_(4)(415 m V)at 10 m A cm^(-2),and a low Tafel slope of 50 m V dec^(-1)in 1 M KOH,which was even better than commercial RuO_(2)at high potential.This modulation approach provides us with valuable insights for exploring efficient and robust water-splitting electrocatalysts.

The Dynamic Properties of a Deterministic SIR Epidemic Model in Discrete-Time

In this paper, a class of discrete deterministic SIR epidemic model with vertical and horizontal transmission is studied. Based on the population assumed to be a constant size, we transform the discrete SIR epidemic model into a planar map. Then we find out its equilibrium points and eigenvalues. From discussing the influence of the coefficient parameters effected on the eigenvalues, we give the hyperbolicity of equilibrium points and determine which point is saddle, node or focus as well as their stability. Further, by deriving equations describing flows on the center manifolds, we discuss the transcritical bifurcation at the non-hyperbolic equilibrium point. Finally, we give some numerical simulation examples for illustrating the theoretical analysis and the biological explanation of our theorem.

Synthesis and superconductivity in yttrium superhydrides under high pressure

Flourishing rare earth superhydrides are a class of recently discovered materials that exhibit near-room-temperature superconductivity at high pressures,ushering in a new era of superconductivity research at high pressures.Yttrium superhydrides drew the most attention among these superhydrides due to their abundance of stoichiometries and excellent superconductivities.Here,we carried out a comprehensive study of yttrium superhydrides in a wide pressure range of 140 GPa-300 GPa.We successfully synthesized a series of superhydrides with the compositions of YH_(4),YH_(6),YH_(7),and YH_(9),and reported superconducting transition temperatures of 82 K at 167 GPa,218 K at 165 GPa,29 K at 162 GPa,and230 K at 300 GPa,respectively,as evidenced by sharp drops in resistance.The structure and superconductivity of YH_(4) were taken as a representative example and were also examined using x-ray diffraction measurements and the superconductivity suppression under external magnetic fields,respectively.Clathrate YH_(10),a candidate for room-temperature superconductor,was not synthesized within the study pressure and temperature ranges of up to 300 GPa and 2000 K.The current study established a detailed foundation for future research into room-temperature superconductors in polynary yttrium-based superhydrides.

Longwall face roof disaster prediction algorithm based on data model driving

Hydraulic support is the primary equipment used for surrounding rock control at fully mechanized mining faces.The load,location,and attitude of the hydraulic support are important sets of basis data to predict roof disasters.This paper summarized and analyzed the status of coal mine safety accidents and the primary influencing factors of roof disasters.This work also proposed monitoring characteristic parameters of roof disasters based on support posture-load changes,such as the support location and support posture.The data feature decomposition method of the additive model was used with the monitoring load data of the hydraulic support in the Yanghuopan coal mine to effectively extract the trend,cycle period,and residuals,which provided the period weighting characteristics of the longwall face.The autoregressive,long-short term memory,and support vector regression algorithms were used to model and analyze the monitoring data to realize single-point predictions.The seasonal autoregressive integrated moving average(SARIMA)and autoregressive integrated moving average(ARIMA)models were adopted to predict the support cycle load of the hydraulic support.The SARIMA model is shown to be better than the ARIMA model for load predictions in one support cycle,but the prediction effect of these two algorithms over a fracture cycle is poor.Therefore,we proposed a hydraulic support load prediction method based on multiple data cutting and a hydraulic support load template library.The constructed technical framework of the roof disaster intelligent prediction platform is based on this method to perform predictions and early warnings of roof disasters based on the load and posture monitoring information from the hydraulic support.

Optimal Design of the Superstructure of an Offshore Tourism Platform by Using Numerical Simulation

This paper aims to reduce the wind resistance of the self-designed offshore tourism platform by optimizing its superstructure,and a transparent shape design is finally suggested.A numerical simulation was performed to calculate the wind load on the platform to test the effect of wind resistance reduction.Two original scale models(sealed and transparent)were established in accordance with the design requirements.The numerical simulation uses the FLUENT software combined with the built-in self-compiled user-defined function(UDF).The stochastic wind was also applied on the basis of the Davenport wind spectrum.The detached eddy simulation(DES)model was used to solve the NS equation.Numerical simulation results show that the wind resistance reduction for the transparent shape model is subtle in the horizontal direction but can effectively reduce the drag force and moment in the vertical direction.Moreover,the force variation of the transparent shape model under different wind attack angles decreases,which reduces the wind load fluctuations.

In-situ structural evolution of Bi_(2)O_(3) nanoparticle catalysts for CO_(2) electroreduction

Under the complex external reaction conditions,uncovering the true structural evolution of the catalyst is of profound significance for the establishment of relevant structure–activity relationships and the rational design of electrocatalysts.Here,the surface reconstruction of the catalyst was characterized by ex-situ methods and in-situ Raman spectroscopy in CO_(2)electroreduction.The final results showed that the Bi_(2)O_(3) nanoparticles were transformed into Bi/Bi_(2)O_(3) two-dimensional thin-layer nanosheets(NSs).It is considered to be the active phase in the electrocatalytic process.The Bi/Bi_(2)O_(3) NSs showed good catalytic performance with a Faraday efficiency(FE)of 94.8%for formate and a current density of 26 mA cm^(−2) at−1.01 V.While the catalyst maintained a 90%FE in a wide potential range(−0.91 V to−1.21 V)and long-term stability(24 h).Theoretical calculations support the theory that the excellent performance originates from the enhanced bonding state of surface Bi-Bi,which stabilized the adsorption of the key intermediate OCHO^(∗) and thus promoted the production of formate.

Cold Start Problem of Vehicle Model Recognition under Cross-Scenario Based on Transfer Learning

As a major function of smart transportation in smart cities,vehicle model recognition plays an important role in intelligent transportation.Due to the difference among different vehicle models recognition datasets,the accuracy of network model training in one scene will be greatly reduced in another one.However,if you don’t have a lot of vehicle model datasets for the current scene,you cannot properly train a model.To address this problem,we study the problem of cold start of vehicle model recognition under cross-scenario.Under the condition of small amount of datasets,combined with the method of transfer learning,load the DAN(Deep Adaptation Networks)and JAN(Joint Adaptation Networks)domain adaptation modules into the convolutional neural network AlexNet and ResNet,and get four models:AlexNet-JAN,AlexNet-DAN,ResNet-JAN,and ResNet-DAN which can achieve a higher accuracy at the beginning.Through experiments,transfer the vehicle model recognition from the network image dataset(source domain)to the surveillance-nature dataset(target domain),both Top-1 and Top-5 accuracy have been improved by at least 20%.

Clinical outcome following radical hysterectomy and pelvic lymphadenectomy for early-stage cervical cancer

Objective： To estimate the impact of parametrial infiltration and lymph node metastasis on clinical outcome in women with early-stage cervical cancer following radical hysterectomy and pelvic lymphadenectomy. Methods： Clinical records and pathologic slides of 532 patients with early-stage cervical cancer （330 Ib and 202 Ila） treated with radical hysterectomy and pelvic lymphadenectomy were reviewed. The study group comprised 520 patients with squamous call carcinoma and 12 patients with adenocarcinoma of the cervix. Median follow-up time was 67 months. The association among the various histopathologic predictors of outcome was determined with analysis. The influence of the predictors on outcome was examined with log rank survival methods and the Cox regression model. Results： FIGO stage, histologic type, tumor size, depth of invasion, parametdal infiltration, lymph node metastasis, and remote metastasis were identified as significantly biologically relevant and therefore were included as candidate predictors in multivariate analysis. In particular, parametrial infiltration and lymph node metastasis were found to be simultaneous predictors of death on multivariate analysis （P 〈 0.05）. After controlling for these two factors, the other variables considered were not statistically significant up to a two-way interaction. Conclusion： Presence of parametdal infiltration and/or lymph node metastasis in women with early-stage cervical cancer is an independent poor prognostic factor. In addition, the relatively poor survival of women with more than one lymph nodes identified with cancer cells.

Oxygen vacancies and V co-doped Co_(3)O_(4) prepared by ion implantation boosts oxygen evolution catalysis

Introducing heteroatoms and defects is a significant strategy to improve oxygen evolution reaction(OER)performance of electrocatalysts.However,the synergistic interaction of the heteroatom and defect still needs further investigations.Herein,we demonstrated an oxygen vacancy-rich vanadium-doped Co_(3)O_(4)(V-Ov-Co_(3)O_(4)),fabricated by V-ion implantation,could be used for high-efficient OER catalysis.X-ray photoelectron spectra(XPS)and density functional theory(DFT)calculations show that the charge density of Co atom increased,and the reaction barrier of reaction pathway from O∗to HOO∗decreased.V-Ov-Co_(3)O_(4) catalyst shows a low overpotential of 329 mV to maintain current density of 10 mA·cm^(−2),and a small Tafel slope of 74.5 mV·dec^(−1).This modification provides us with valuable perception for future design of heteroatom-doped and defect-based electrocatalysts.

Lumbar Paraspinal Hemangiopericytoma, An Unusual Location: Surgery with Preoperative Embolization

Background: Lumbar paraspinal hemangiopericytoma is rare. The hemorrhagic nature of the tumor causes problems of hemostasis and makes the resection delicate. We report a rare case of lumbar paraspinal hemangiopericytoma managed with preoperative embolization. Clinical Case: It is about a woman of 31 years, admitted for a large left lumbar paraspinal mass that evolved for 6 years. The clinical exam showed an asymmetry of the left paraspinal muscle. The mass painless was extended from the lumbar region. The neurological exam was normal. MRI showed the left large paraspinal mass tissue. It was extended from lumbar vertebrae, L1 to L4, and measured 100 × 50 × 50 mm. It was an iso-intense signal on T1-weighted with strong enhancement after gadolinium. It was hypervascular and supplied by left intercostal T12, L1, and L2 pedicles. The complete exclusion of the hyper-vascular left paraspinal tumor was obtained after selective embolization of the artery left L1 of the pedicle of the intercostal left L1 and trunks intercostal T12 and L2 left. The total resection of a mass encapsulated was performed. The operative outcome was good. The histology concluded to a hemangiopericytoma. No chemotherapy or radiotherapy was prescribed. After 5 years, the patient was asymptomatic. MRI control confirmed tumor resection with a residue at the level of the left intervertebral foramen L1 - L2. Conclusion: Lumbar paraspinal hemangiopericytoma is an extremely rare tumor. Selective preoperative embolization is recommended before the resection of large tumors to reduce vascular supply. A follow-up extended for these patients is necessary, given the frequency of recurrences.