mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Charging dynamics of a polymer due to electron irradiation: A simultaneous scattering-transport model and preliminary results

We present a novel numerical model and simulate preliminarily the charging process of a polymer subjected to electron irradiation of several 10 keV. The model includes the simultaneous processes of electron scattering and ambipolar transport and the influence of a self-consistent electric field on the scattering distribution of electrons. The dynamic spatial distribution of charges is obtained and validated by existing experimental data. Our simulations show that excess negative charges are concentrated near the edge of the electron range. However, the formed region of high charge density may extend to the surface and bottom of a kapton sample, due to the effects of the electric field on electron scattering and charge transport, respectively. Charge trapping is then demonstrated to significantly influence the charge motion. The charge distribution can be extended to the bottom as the trap density decreases. Charge accumulation is therefore balanced by the appearance and increase of leakage current. Accordingly, our model and numerical simulation provide a comprehensive insight into the charging dynamics of a polymer irradiated by electrons in the complex space environment.
Electronic structures and optical properties of Zn-doped β-Ga_2O_3 with different doping sites

The electronic structures and optical properties of intrinsic β-Ga_2O_3 and Zn-doped β-Ga_2O_3 are investigated by first-principles calculations. The analysis about the thermal stability shows that Zn-doped β-Ga_2O_3 remains stable. The Zn doping does not change the basic electronic structure of β-Ga_2O_3, but only generates an empty energy level above the maximum of the valence band, which is shallow enough to make the Zn-doped β-Ga_2O_3 a typical p-type semiconductor. Because of Zn doping, absorption and reflectivity are enhanced in the near infrared region. The higher absorption and reflectivity of Zn_(Ga(2)) than those of Zn_(Ga(1)) are due to more empty energy states of Zn_(Ga(2)) than those of Zn_(Ga(1)) near Ef in the near infrared region.
Multi-relaxation-time lattice Boltzmann front tracking method for two-phase flow with surface tension

In this paper, an improved incompressible multi-relaxation-time lattice Boltzmann-front tracking approach is proposed to simulate two-phase flow with a sharp interface, where the surface tension is implemented. The lattice Boltzmann method is used to simulate the incompressible flow with a stationary Eulerian grid, an additional moving Lagrangian grid is adopted to track explicitly the motion of the interface, and an indicator function is introduced to update the fluid properties accurately. The interface is represented by using a four-order Lagrange polynomial through fitting a set of discrete marker points, and then the surface tension is directly computed by using the normal vector and curvature of the interface. Two benchmark problems, including Laplace's law for a stationary bubble and the dispersion relation of the capillary wave between two fluids are conducted for validation. Excellent agreement is obtained between the numerical simulations and the theoretical results in the two cases.
Static electric dipole polarizability of lithium atoms in Debye plasmas

The static electric dipole polarizabilities of the ground state and n ≤ 3 excited states of a lithium atom embedded in a weekly coupled plasma environment are investigated as a function of the plasma screening radium. The plasma screening of the Coulomb interaction is described by the Debye-Huckel potential and the interaction between the valence electron and the atomic core is described by a model potential. The electron energies and wave functions for both the bound and continuum states are calculated by solving the Schrodinger equation numerically using the symplectic integrator. The oscillator strengths, partial-wave, and total static dipole polarizabilities of the ground state and n ≤ 3 excited states of the lithium atom are calculated. Comparison of present results with those of other authors, when available, is made. The results for the 2s ground state demonstrated that the oscillator strengths and the static dipole polarizabilities from np orbitals do not always increase or decrease with the plasma screening effect increasing, unlike that for hydrogen-like ions, especially for 2s→3p transition there is a zero value for both the oscillator strength and the static dipole polarizability for screening length D = 10.3106a0, which is associated with the Cooper minima.
Infrared emissivities of Mn, Co co-doped ZnO powders

Infrared emissivities of Zn0.99-_xMn0.01Co_xO (x = 0.00, 0.01, 0.03, 0.05) powders synthesized at different calcination temperatures by solid-state reaction are investigated. Their phases, morphologies, UV absorption spectra, and infrared emissivities are studied by XRD, SEM, UV spectrophotometer, and an IR-2 dual-band infrared emissometer in a range of 8 μm-14 μm. Doped ZnO still has a wurtzite structure, and no peaks of other phases originating from impurities are detected. The optical band-gap decreases as the Co content and calcination temperature ascend, and of which the smallest optical band gap is 2.19 eV. The lowest infrared emissivity, 0.754, is observed in Zn_(0.98)Mn_(0.01)Co_(0.01)O with the increase in Co concentration. The infrared emissivity experiences fluctuations as the calcination temperature increases, and its minimum value is 0.762 at 1100 °C.
Generalized projective synchronization of fractional-order complex networks with nonidentical nodes

This paper investigates the synchronization problem of fractional-order complex networks with nonidentical nodes. The generalized projective synchronization criterion of fractional-order complex networks with order 0 < q < 1 is obtained based on the stability theory of the fractional-order system. The control method which combines active control with pinning control is then suggested to obtain the controllers. Furthermore, the adaptive strategy is applied to tune the control gains and coupling strength. Corresponding numerical simulations are performed to verify and illustrate the theoretical results.
~(125)I粒子植入治疗肺癌的新进展

近年来,随着恶性发病率的不断提高,对于失去手术机会或不愿接受手术治疗的恶性肿瘤患者的综合治疗愈来愈得到广泛的重视,其中~(125)I粒子组织间植入内放射应用于临床,作为治疗肿瘤的一种新方法,已逐渐被广大患者和医务人员所接受。与外放射治疗相比,体内近距离植入放疗的优点为直接植入靶肿瘤,连续低剂量的长时间放疗,使肿瘤组织遭受最大程度的杀伤,使正常组织不损伤或仅有微小损伤,从而提高放疗的准确性和持续性。对提高肺癌患者的生存率和降低局部复发率,改善生存质量,预防肺癌的复发转移有一定的作用,因此成为治疗癌的一种重要手段。
丹红注射液治疗中老年糖尿病周围神经病变20例

糖尿病周围神经病变主要与机体长期的高血糖状态有关。其临床表现通常为对称性,下肢较上肢严重,可伴随痛觉过敏、疼痛;随病情进展,可累及运动神经,肌力减弱,重者出现肌萎缩和瘫痪。因此,改善局部血流动力学及微循环,有极其重要的意义~((1))。
恶性骨肿瘤患者住院期间生活质量及其影响因素

目的探讨恶性骨肿瘤患者住院期间的生活质量及其影响因素。方法应用问卷调查方法,采用患者背景资料调查表、癌症患者生活质量调查量表〔EORTCQLQ-C30中文版量表〕调查在长沙市三家三级医院住院的100例原发恶性骨肿瘤患者。测定和评估他们的生活质量状况。结果住院期间恶性骨肿瘤患者生活质量的得分处于较低水平,以角色功能、疼痛症状和经济困难最为明显。其影响因素有:性别、年龄、文化程度、家庭年收入等。结论原发性恶性骨肿瘤患者住院期间生活质量的影响因素与患者的性别、年龄、文化程度、家庭经济状况等有关,其中26~35岁的患者生活质量最低。
国产培美曲塞联合顺铂并同步或序贯脑放疗治疗非小细胞肺癌脑转移的疗效

目的探讨国产培美曲塞联合顺铂全身化疗并同步或序贯脑放疗治疗非小细胞肺癌(NSCLC)脑转移患者的疗效与毒副反应。方法分析2005年1月至2010年1月NSCLC脑转移患者46例,其中23例接受培美曲塞联合顺铂全身化疗同步脑放疗(同步组),23例采用培美曲塞联合顺铂全身化疗序贯脑放疗(序贯组)。结果共45例患者完成治疗,全身病灶的总体客观缓解率(ORR)为24.4%;脑转移灶的ORR为33.3%,中位无进展生存期(PFS)为3.67个月,中位生存期(MST)为16.7个月,1年和2年总生存率分别为56%和25.4%。同步组和序贯组全身病灶的总体ORR分别为22.7%和26.1%,脑转移灶的ORR分别为40.9%和26.1%,中位PFS分别为4个月和5个月,MST分别为17个月和14个月,差异均无统计学意义(均P>0.05)。同步组和序贯组的1年生存率分别为56.7%和50.8%(P>0.05),2年生存率分别为38.4%和20.1%,同步组明显优于序贯组(P=0.009)。序贯组的白细胞减少的发生率低于同步组(P=0.026);其他毒副反应的发生率差异无统计学意义(P>0.05)。结论国产培美曲塞联合顺铂身化疗并同步脑放疗治疗NSCLC脑转移可以取得较好疗效,且患者耐受良好。
加长喷头吸入硫酸沙丁胺醇气雾剂治疗建立人工气道支气管哮喘患者的疗效

目的观察加长喷头吸入硫酸沙丁胺醇气雾剂对建立人工气道支气管哮喘患者的效果。方法将80例患者按住院日期分组,单日为观察组,双日为对照组。比较两组患者用药后1、5、10min缓解率及平均缓解时间,监测用药10min后两组患者的心率及呼吸和血液中PaO_2、SaO_2、PaCO_2、pH、Lac的变化。结果两组患者的1、5、10min缓解率差异明显(P<0.05),观察组平均缓解时间明显短于对照组(P<0.05),而对照组无效例数较多(P<0.01)。药物干预10min后,观察组患者的PaO_2较对照组明显增高(P<0.05),PaCO_2、pH和呼吸次数较对照组下降(P<0.05),两组患者的心率、SaO_2及Lac水平变化不大(P>0.05)。结论加长喷头提高了人工气道患者使用硫酸沙丁胺醇气雾剂的效果。
刺五加配伍桅子治疗老年抑郁障碍患者的疗效

目的研究刺五加配伍桅子治疗老年抑郁障碍患者的临床疗效。方法选择95例老年抑郁障碍患者作为研究对象,根据双盲原则随机分为给予刺五加配伍桅子治疗的观察组(48例)和逍遥散治疗的对照组(47例),观察治疗效果、负面情绪以及社会功能。结果观察组治疗的总有效率91.67%,明显好于对照组;HAMD评分、HAMA评分、职业功能、婚姻职能、父母职能、社会退缩、社会活动、家里活动、家庭职能、自我照顾、关心社会、责任心总分均明显低于对照组。结论刺五加配伍栀子能够提高治疗有效率,缓解负面情绪,对于老年抑郁障碍的治疗具有积极意义。
急性额颞叶脑内血肿的显微手术治疗

综上所述,我们认为因血肿占位效应明显,甚至已经形成脑疝的病例应该以尽快解除脑疝和占位效应为首要目标,其次再考虑出血病因的处理,不能因为强调完善术前检查而延误手术时机。对于出血量大,早期脑疝,GCS 7分以下的患者应该尽早手术挽救生命,同时手术还可以显著改善近期和远期预后及生活能力。
卡波血管内皮瘤一例

讨论卡波血管内皮瘤是一种罕见的局部浸润性生长的血管内皮细胞来源的肿瘤,多发生于儿童期。一般起源于皮肤,可以影响深部组织。无远处转移,常伴有消耗性凝血病。临床上需与卡波肉瘤、无色素恶性黑色素瘤、梭形细胞血管内皮瘤、簇绒状血管瘤、毛细血管血管母细胞瘤、血管肉瘤等鉴别。确诊需要组织学检查和免疫组化验查。手术切除是最有效治疗方法,非手术治疗包括局部放射.病例报告.治疗、血管栓塞治疗、干扰素、糖皮质激素、环磷酰胺、长春新碱等。在大多数成功病例采用综合治疗。本例患者经过彻底手术切除,半年随访无复发。
岩骨内内听道表皮样囊肿一例

讨论颅骨表皮样囊肿是胚胎发育过程中残留的外胚叶组织异位于颅骨内,逐渐生长堆积而成(Am J Otol,1998,19:292-297.)。多位于板障内,并使内外板分开、变薄破坏,.病例报告.呈虫蚀样改变。颅骨表皮样囊肿常发生于额骨,其次为颞骨、顶骨,以20一50岁为最多见。应与颅内硬膜下表皮样囊肿(尤其是近颅底岩骨者)相鉴别。颅内硬膜下表皮样囊肿多见于小脑脑桥角和中颅窝,在起源和病理上与前者一致,主要表现为颅内占位,一般无颅骨破坏,头颅x线、CT及MRI检查可显示颅骨表皮样囊肿及其与周围结构的关系,是诊断的重要方法,以高分辨率薄层颅骨Cr扫描为首选(实用放射学杂志,2004,20:489-492.)。CT上典型表现为膨胀性、均质中、高密度软组织影,边缘清晰,均质无明显强化。MRI图像上典型表现为TIWI呈中等信号,T2WI则呈高信号的软组织病灶,肿块部分边缘可呈弧线样增强。MRI在判定颅骨表皮样囊肿的范围及显示侵及颅内外的病灶时较CT全面,手术切除是治疗的惟一有效方法。
螺旋CT三维血管成像对颅底脑膜瘤的术前评估

脑膜瘤是中枢神经系统常见的肿瘤之一,发病率仅次于胶质瘤,约占颅内原发肿瘤的15%~20%。瘤基底与前、中、后颅窝底附着的脑膜瘤统称为颅底脑膜瘤。一般来讲,颇底脑膜瘤诊断和治疗都较困难,肿瘤容易侵犯大脑动脉环(即Willis环)及分支血管和脑神经。颅底脑膜瘤对Willis环及脑神经损害多见,手术射刀除困难。三维CT血管造影(three-dimensional computed tomography angiography,3D-CTA)主要应用于脑血管疾病的诊断(特别是脑动脉瘤)等;在颅脑肿瘤的应用方面,用于颅底血供丰富肿瘤,但此类文献报道尚少。本文主要对3D-CTA在颅底脑膜瘤术前评估肿瘤部位、大小、血供、与周围血管的关系、颅骨受侵犯程度及对手术人路的设计方面进行研究,以评估3D-CTA在其中的临床价值。
CD133:脑胶质瘤干细胞标志物?

过去十五年.癌症研究中的重大进展之一为“肿瘤干细胞”模式的提出。该模式认为,恶性肿瘤的发生类似于正常组织发生,最初起源于与“正常干细胞”具有相类似的自我更新和多向分化潜能特性的“肿瘤干细胞。细胞表面分子CD133在各类肿瘤干细胞的分选及鉴定中广泛应用。然而最近,CD133分子在脑胶质瘤、结直肠癌、肺癌等恶性肿瘤组织中作为肿瘤干细胞标志物的作用受到了质疑,例如,在脑胶质瘤中的研究表明,CD133阴性的肿瘤细胞在体外实验中也可具备自我更新及多向分化能力,在免疫缺陷鼠中亦可有效导致肿瘤发生;而且CD133阴性肿瘤细胞在免疫缺陷鼠中所诱发的肿瘤可包含CD133阳性肿瘤细胞。因此,CD133分子作为肿瘤干细胞,尤其是脑胶质瘤干细胞标志物的特异性成为当前研究的热点。
术中超声对迟发性硬膜外血肿所致急性脑膨出的诊断与治疗

重型颅脑损伤开颅术中有时会出现急性脑膨出,起病急骤,进展快,手术者处理有时颇为困难,对侧迟发性硬膜外血肿为常见原因,既往多需复查头颅CT确诊后再行硬膜外血肿清除术。我科自2007年4月至2010年12月术中应用超声协助治疗该类患者共22例,取得了较好的临床效果。现总结报告如下。
颅内血管外皮细胞瘤一例报告及文献复习

血管外皮细胞瘤(hemangjopericytoma,HPC)又名血管周细胞瘤,是一种不常见的软组织恶性肿瘤,多发生于身体各部位软组织中,以肺、骨骼最多见,其次可见于肾、肝脏和皮肤,很少发生于中枢神经系统,颅内HPC占颅内肿瘤不到0.5%。HPC可以复发,并且可以远处转移,颅外最常见转移至骨、肝、肺,也有报道转移至肾上腺、肾,乳腺等多发转移。
神经纤维瘤病Ⅰ型伴发颈髓间变神经节细胞胶质瘤一例并文献复习

神经节细胞胶质瘤是一种混合成分的肿瘤,多见于颅内幕上.脊髓神经节细胞胶质瘤少见,同时伴发颈髓间变神经节细胞胶质瘤和神经纤维瘤病Ⅰ型(NF1)的病例鲜有报道.现将北京天坛医院神经外科中心诊治的1例10年随访并经病理证实的间变神经节胶质细胞瘤进行报告并文献复习.
脑血管重建术与围手术期脑血流监测

脑血管重建术是指采用手术方法重新建立脑的侧支循环通路,包括颅外-颅内动脉吻合术(extracranial -intracranial bypass,EC - IC bypass)等直接血管吻合技术,或头皮动脉-硬脑膜动脉-颞肌-脑皮质血管粘连成形术等间接建立脑血流等方法.其主要目的:(1)在主要颅内血管需要阻断时,起代偿作用,如颅内动脉瘤治疗中阻断载瘤动脉和颅底手术切除侵犯血管的肿瘤时;(2)重建已闭塞的血管,预防进一步发生缺血,常见于脑缺血和烟雾病(Moyamoya)病的治疗中.
分泌性脑膜瘤瘤周水肿发生的因素

分泌性脑膜瘤(secretory meningiomas)是一种少见的良性脑膜瘤亚型,在所有脑膜瘤中占1.0%~4.4%,在神经系统肿瘤的WHO(2000)分类中WHO分级Ⅰ级,1986年由Alguacil-Garcia首先命名并报道,主要原发于颅内,也有报道原发于颞骨表现为中耳炎,生长缓慢,但可以引起严重的脑水肿和危及生命的并发症,其确切的发病机制还不是十分明确.预后相对较好,主要与手术的切除程度有关,目前报道的全切除者中均无复发.在以往的研究中,男女比例不尽相同,但可以肯定女性高发,根据以往的研究:女性患者所占的比例在75%到100%之间,平均为85%,但是最新的一项研究为59%.据统计从PubMed中得到的文献资料,该病多见于中老年患者,年龄在30岁-87岁,平均在46岁-65岁。其有典型的上皮膜特征,细胞排列成腺样。腺腔内含有PAS阳性分泌物,免疫组化测定示角化素(+),癌胚抗原(CEA)(+),所有患者孕酮受体、部分患者雌激素受体阳性,MIB 1扩增指数在l%到7%之间。
小脑脑桥角区髓母细胞瘤一例报告并文献复习

小脑脑桥角区髓母细胞瘤临床少见,以成人发病为主,发病率不到成人髓母细胞瘤的l0%,无明显性别差异。小脑脑桥角区髓母细胞瘤病程起病快,这与成人颅缝已闭合代偿颅内高压能力减弱有关,临床表现以恶心、呕吐、视乳头水肿等颅内高压及行走不稳、肢体共济失调等小脑功能障碍为主。与小脑脑桥角区其他肿瘤常引起Ⅶ、Ⅷ等脑神经功能障碍不同,髓母细胞瘤少以脑神经损害起病。
缺氧诱导胶质瘤干细胞向血管内皮细胞分化潜能的实验研究

胶质瘤占脑内肿瘤的40%~45%,具有高侵袭性、髙度增殖性,传统手术加放化疗等综合治疗手段主要针对的是肿瘤细胞,疗效不佳[1-3]。根据肿瘤的生长、侵袭有赖于肿瘤血管生成的理论产生了抗肿瘤血管生成治疗肿瘤策略,但目前常规的抗肿瘤血管生成治疗效果仍不尽人意[4],说明可能存在其他的肿瘤血管生成的机制或其他影响肿瘤血管生成的因素。缺氧可上调人血管内皮细胞生长因子(vascular endothelial growth factor, VEGF)及其受体(VEGFR)的表达,而VEGF是刺激肿瘤血管生成最关键的生长因子,本研究在缺氧条件下培养脑胶质瘤干细胞,探讨其与肿瘤血管生成的关系,为改进抗肿瘤血管生成策略提供新的思路。
经皮下隧道带蒂皮瓣转移治疗颅骨成形材料外露一例

讨论我们体会在颅骨成形术中进行皮瓣分离时,要保证皮瓣有一定厚度,以防皮肤坏死、缺损、材料外露;一旦出现以上情况,就应立即进行带蒂皮瓣移植术,不应侥幸进行直接缝合尝试,因为缺乏足够皮下组织支持的皮瓣(尤其是在额部)很难愈合;在进行皮瓣移植术时,一定要将带蒂皮瓣的游离端直接缝合到钛板上,这样皮瓣就会和其下方的硬膜软组织愈合,并且可以减少皮肤缝合时的张力,增加愈合机会,而且只要皮辦的皮下组织与受区愈合了,移植术就会成功,即使皮肤部分坏死也不会影响愈合。在进行转移皮瓣修复之前,要确保无感染或感染已经彻底控制,否则很难达到愈合目的。此外,带蒂皮瓣移植时一般要求长轴内保留至少一条供血动脉,这样才能保证皮瓣成活。
脊神经根血管母细胞瘤一例

血管母细胞瘤约占椎管内肿瘤的1.6%-5.8%,其中约33%的血管母细胞瘤伴发Von Hippel - Lindau综合征。发生在髓外的血管母细胞瘤非常罕见。髓外血管细胞可以发生在终丝、近端神经根甚至远端神经根(如正中神经、桡神经)。神经根血管细脑大多发生腰段,对于椎管内硬膜下病变,术前鉴别诊断中应该考虑到有该病的可能。MRI影像表现为等或长T1、长T2信号,均匀强化,如肿瘤体积较大,可见血管流空影。少数病例血常规可见血红蛋白稍升高。由于该肿瘤多与神经根粘连紧密,全侧中瘤后而神经根完好非常困难。
经侧裂-岛叶入路治疗高血压基底节区脑出血的体会

出血性脑卒中占全部中风患者的21%-48%,死亡率和致残率居各类卒中之首,发病后1个月内病死率高达30%~50%,存活者中超过30%遗留有神经功能障碍⑴,手术治疗可使死亡率降至0~22%[2]。如何降低致残率已成为大家研究的主要方向,我院自2004年5月至2010年5月采用经侧裂-岛叶人路显微手术治疗高血压基底节区脑出血患者51例,现报告如下。
舒芬太尼与芬太尼对体外循环下心脏手术患儿心肌缺血再灌注损伤影响的比较

体外循环(CPB)心内直视手术可引起心肌缺血再灌注损伤。阿片类药物是临床麻醉中常用的镇痛药。研究表明,芬太尼对心脏手术患者心肌有保护作用。舒芬太尼是一种高选择性μ受体激动剂,镇痛效力是芬太尼7~10倍,且比芬太尼能更好的抑制应激反应,目前越来越多用于心脏外科手术的麻醉。动物实验和临床试验均表明,舒芬太尼可减轻心肌缺血再灌注损伤。本研究拟比较舒芬太尼与芬太尼对CPB下心脏手术患儿心肌缺血再灌注损伤的影响,为临床麻醉药选择提供依据。
Identification of SUMO Targets by a Novel Proteomic Approach in Plants

Post-translational modifications (PTMs) chemically and physically alter the properties of proteins, including their folding, subcellular localization, stability, activity, and consequently their function. In spite of their relevance, studies on PTMs in plants are still limited. Small Ubiquitin-like Modifier (SUMO) modification regulates several biological processes by affecting protein-protein interactions, or changing the subcellular localizations of the target proteins. Here, we describe a novel proteomic approach to identify SUMO targets that combines 2-D liquid chromatography, immunodetection, and mass spectrometry (MS) analyses. We have applied this approach to identify nuclear SUMO targets in response to heat shock. Using a bacterial SUMOylation system, we validated that some of the targets identified here are, in fact, labeled with SUMO1. Interestingly, we found that GIGANTEA (GI), a photoperiodic-pathway protein, is modified with SUMO in response to heat shock both in vitro and in vivo.
Influence of Polymer Binder on the Physical Properties and Stability of Engineering Spoil on a Slope

An experiment was performed to study the influence of polymer binders on the physical properties, and stability against a simulated rainfall, of a slope consisting of engineering spoil. Results showed that low polymer binder concentrations (≦500 g/m~3) could enhance the air permeability and moisture -retaining capacity of the engineering spoil; however, adding more polymer binder made the hardness of the engineering spoil increase and then decline. With the increase of polymer binder concentrations, the surface (0-5 cm) permeability of the engineering spoil decreased but the permeability of the lower layers (5-10 cm) increased. Polymer binders might reduce runoff and sediment, but the effect becomes weaker with the increase of rainfall. The results of this study have significance for engineering practices. Further experiments are needed to study the effects of binders under other conditions, such as natural rainfall, different slopes, different rock types, different degrees and spoil weathering and different added material, and the chemical interaction between soil and polymer binders.
Forces Driving Changes in Cultivated Land and Management Countermeasures in the Three Gorges Reservoir Area, China

The Three Gorges project accelerates economic development in the Three Gorges Reservoir Area. This paper aimed to investigate the distribution, changes and features of cultivated land in this area, analyze the forces driving the changes in cultivated land area, and propose the countermeasures for cultivated land management. Transition matrix was used to analyze the features of cultivated land changes, and quantitative analysis and qualitative analysis were adopted to research the driving forces according to the features of cultivated land changes. Cultivated land in the Three Gorges Reservoir Area mainly lay to the northwest of the Yangtze River, especially the upper reaches. The areas of cultivated land increased from 1996 to 1999, then decreased from 2000 to 2006, and finally increased again from 2007 to 2009. The important forces driving changes in cultivated land included government policies, employment and food security, increasing construction land, agriculture structure adjustment, land rearrangement, inundation. During cultivated land management, firstly, it is necessary to insist on the principle of cultivated land protection, standardize land exploitation and strictly restrict the transformation of cultivated land into non-farming land. Secondly, land rearrangement must be implemented, which can not only increase the area of the cultivated land, but also improve the quality of the cultivated land. Thirdly, it is feasible to intensify eco-agriculture construction to increase the quantity and quality of cultivated land. Fourthly, it is helpful to improve the traditional agriculture production methods to promote cultivated land quality. Lastly, it is important to propagandize cultivated land protection and realize the enormous pressure of cultivated land shortage, making more people obligated to protect cultivated land.
醛固酮与肾素比值对原发性醛固酮增多症的筛查与诊断价值

目的:评价生化检查、影像学和选择性肾上腺静脉取血对原发性醛固酮增多症(原醛)分型诊断方法的价值及影响预后的因素。方法:采用回顾性研究,对124例原醛患者的临床相关检查、术后病理结果及术后随访结果进行分析。结果:①91.1%的原醛患者血钾<3.5 mmol/L;81.5%的患者血浆醛固酮/血浆肾素活性比值(ARR)> 50;②与结节样增生组比较,醛固酮腺瘤(APA)组的激发血浆肾素活性显著降低、血醛固酮和ARR显著增高(P< 0.05);APA和结节样增生组的血醛固酮和ARR均显著高于增生组(P<0.05);③肾上腺B超诊断APA的敏感性14.3%,特异性23.1%;肾上腺CT诊断APA的敏感性85.7%,特异性21.7%;④APA手术治愈率为40.9%,有效率为50.0%;特发性醛固酮增多症(IHA)手术治疗有效率8.3%。结论:ARR可用于原醛的筛查;结节样增生可能是APA和IHA之间的中间型;肾上腺CT是原醛定位诊断的主要方法,但对APA诊断的准确性并不高;病理类型是影响预后的主要因素。
康复新液联合美沙拉秦治疗68例溃疡性结肠炎的临床疗效

68例溃疡性结肠炎患者,随机分为治疗组38例(美沙拉秦+康复新)、对照组30例(美沙拉秦),疗程均为4周。以治疗前后临床症状、结肠镜下溃疡愈合情况及治疗后1年溃疡愈合情况为观察指标。康复新联合美沙拉秦治疗溃疡性结肠炎的临床症状缓解、溃疡愈合及溃疡复发均优于对照组。
全麻诱导插管牙齿脱落误入气管一例

讨论全麻诱导喉镜暴露和气管插管期间牙齿损伤、脱落偶有发生,尤其是老年患者、困难插管患者和牙齿畸形的患者。但牙齿损伤脱落后误入气管内的情况非常少见。该患者年龄偏大,仅剩3颗上门齿,且稀疏。插管期间喉镜暴露声门困难,需按压喉结方可看见少许,同时需插入双腔气管导管,属困难气道患者,是牙齿损伤脱落的主要原因。麻醉医师插管前后忽视了观察患者牙齿数,错过补救第一步;同时为插管后气道压异常升高正确诊断造成障碍,导致误诊为体位引起肿瘤压迫肺脏致气道压异常升高。值得庆幸的是术后48 h内及时发现,及时会诊,与家属沟通后取得积极配合,制定了第二步补救方案:纤维支气管镜取出牙齿,同时做好开胸取牙齿的准备,结果牙齿顺利取出,未造成患者进一步损伤。
Optimizing Design on AC Filters in Jinping-Sunan ±800 kV UHVDC Project

In DC transmission systems,AC filters can effectively reduce the hazards of harmonics, and compensate the reactive power requirements of the converters, thus the type and parameter choice of the filters is important. Therefore, based on the system conditions of Jinping-Sunan ± 800 kV UHV DC (ultra-high voltage direct current) transmission project and the main harmonics,three types of filters were designed. The parameters of filter components were determined according to the reactive power compensation. By calculating the filter performance and rating, the results show that the parallel tuning with greatly over-currents appears in the low-voltage arm of BP11/13 filter. In order to avoid this kind of danger, a filter named BP11/BP13 is designed. Studies show that this type of filter can fully meet the filter performance requirements and avoid the over-current. It is concluded that the filter BP11/BP13 can reduce the rating of the components and enhance the stability in the long-term operation.
Optimization Research on Valve Hall Grounding Switch Arrangement of UHVDC Project

The switches installed in converter station valve halls in Xiangjiaba-Shanghai ± 800 kV UHVDC project are expensive and maintenance inconvenience. Two optimization schemes of the valve hall grounding switches for researches on the function and operation of the switchers are presented. The two schemes are both studied in detail, with one way of abolishing all grounding switches on transformer valve side,and another way of partly cancelling the switches. Detailed analysis is further carried out for the feasibility and the pros and cons of the two schemes. Based on the comparison of two schemes,the partial reduction of grounding switches is selected to get a simulation with an EMTDC model. Plus in order to verify the reliability of the simulating results, a field test is carried out in Fengxian converter station with the partly switches cancellation scheme. The test results proved that using only one switch can still release residual charge in the valve hall in a relatively short period. Optimized designs of the valve hall switches can save both space and costs of the project.
Overvoltage and Insulation Coordination of Jinping-Sunan ± 800 kV UHVDC Porject Converter Stations

Regarding to the problems of equipments manufacturing and layout in Jinping-Sunan ± 800 kV UHVDC transmission system,overvoltage protection and insulation coordination in converter stations were studied. Configuration of arresters was studied at first, and scheme of MH arresters and V arresters connected in series was used to protect the high voltage Yy transformer's valve side of dual 12-pulse converters. Overvoltage caused by DC faults and the withstand level of equipment in converter stations were studied using electromagnetic transient simulation. Based on operation parameters and characteristics of AC and DC system, equivalent models of both systems were set, together with most of the equipment in converter stations which would influence simulation results. The AC arresters,transient response to AC faults was also simulated. For the most severe case,the peak voltage on AC bus arresters is up to 752 kV,along with stresses about 12.0 MJ in energy and 12.4 kA in current. Simulation results of transient overvoltage in converter stations were used to verify insulation coordination by comparing with the design value. The maximum insulation level would be less than 1 600 kV, which is no more than that in former UHVDC projects.
Research on Converter Valve Overvoltage Mechanism and Calculation Conditions of ± 800 kV Converter Station

The thyristor converter valve is the key equipment of commutation in ultra high voltage direct current(UHVDC) transmission systems. Owing to the limited voltage and current overload capacity, any transient overvoltage may cause permanent damage to the thyristor converter valve. In order to specify the converter valves' overvoltage levels of the ± 800 kV UHVDC transmission system, the mechanisms of its generation and development are discussed in detail, from which the calculation conditions for the highest stresses of the converter valves are given. Finally, the converter valve's overvoltage of Xiluodu UHV converter station is simulated. The research results show that the overvoltages of the converter valves in the upper 3-pulse group of the high voltage(HV) and low voltage(LV)12-pulse converter are generated jointly by the DC line voltage and the converter transformer's voltage at its valve side. Calculation conditions for this overvoltage are: DC system in bipolar operation mode,converter station operating as rectifier,maximum DC system operating voltage, minimum DC current, minimum AC system voltage of the converter station. Furthermore,the other converter valves,overvoltage is caused by the phase-to-phase switching surge generated at the converter station's AC side,penetrating into the valve hall. Overall, the maximum overvoltages of Xiluodu converter station in the upper 3-pulse group of the HV and LV 12-pulse converter are 379.1 kV and 384.9 kV, for other converter valves the maximum overvoltage is 375.3 kV.