IDUS、CT和MRCP对胆道恶性梗阻的诊断价值

目的探讨腔内超声（IDUS）、CT和磁共振胰胆管造影（MRCP）和对胆道恶性梗阻的诊断价值。方法回顾性分析53例胆道恶性梗阻患者的IDUS、CT和MRCP检查结果,比较3种影像学检查方法对胆道恶性梗阻的图像特征和诊断情况。结果IDUS、CT和MRCP对胆道恶性梗阻定位诊断准确率分别为65.31%、82.98%和82.93%,差异有统计学意义（P＜0.05）;而定性诊断准确率分别为63.27%、74.47%和75.61%,差异无统计学意义（P＞0.05）。3种影像学检查方法均能显示胆道恶性梗阻的部位、数量和回声/密度/信号特征：CT和MRCP对壶腹癌定位诊断、胰头癌定性诊断均有较高符合率。IDUS对胆管狭窄性质的阴性预测能力明显高于CT和MRCP（P＜0.05）。结论IDUS、CT和MRCP均能清晰显示胆道恶性梗阻的特征,各有优势,具有较高的应用价值。     

超声乳化晶状体摘除术对不同阶段原发性闭角型青光眼的疗效分析

目的 比较分析超声乳化晶状体摘除术对不同阶段的原发性闭角型青光眼的治疗效果,为临床上闭角型青光眼行 晶状体摘除术治疗的手术时机选择提供依据。方法 收集2008 年7 月至2013 年12 月行超声乳化晶状体囊外摘除术联合人工晶状体植入术的闭角型青光眼患者70 例（共113 眼）,分为临床前期组（40 眼）、急性发作组（48 眼）和慢性进展组（25 眼）3 组,平均随访（19.47±10.10）个月。比较各组患者术前、术后的视力、眼压、视野、房角粘连等参数,以及术后随访过程中青光眼继续进展的情况。结果 临床前期组患者术后均无青光眼进展;急性发作组10.4%患者术后继续进展,继续进展和术前病程相关（r=0.462,P＝0.003）;慢性进展组40.0%患者术后继续进展,继续进展和房角粘连程度相关（r=0.698,P＝0.000）。结论 原发性闭角型青光眼临床前期患者进行晶状体摘除可良好地预防青光眼进展;房角关闭急性发作时尽早行晶状体摘除;慢性进展期在早期,房角粘连未达1/2周之前行晶状体摘除均可有效控制病情发展。     

CT对腹部创伤的临床诊断价值分析

目的 探讨多层螺旋CT 在腹部创伤诊断中的临床价值。方法 对132 例腹部创伤患者的临床资料进行回顾性分析，所有患者入院后均行CT 和彩色超声检查，以手术诊断结果为金标准对检查结果进行分析。结果 CT 检查对腹部创伤诊断的灵敏度、特异度和准确率分别为93.67%、97.06%、94.69%；彩色超声检查对腹部创伤诊断的灵敏度、特异度和准确率分别为86.96%、86.36% 和86.73%；两种检查灵敏度、特异度和准确率比较差异均有统计学意义（均P＜0.05）。结论 CT 对腹部创伤诊断的准确率、灵敏度及特异度都较高，可作为腹部创伤后对实质脏器损伤情况评价的重要影像学检查方法。     

单发肺炎实变型肺MALT淋巴瘤的多排螺旋CT诊断及鉴别

目的分析单发肺炎实变型肺黏膜相关淋巴组织（MALT）淋巴瘤的多排螺旋CT（MSCT）表现，以提高其诊断及鉴别诊断水平。方法回顾性分析11例患者经手术病理证实的单发肺炎实变型肺MALT淋巴瘤的MSCT和临床资料。结果11例患者中右肺中叶5例，下叶2例，左肺上叶1例，下叶3例；大叶性实变7例，节段性实变3例，非节段性实变1例；2例病灶边缘模糊，类似于炎症，6例边缘模糊程度介于炎症与肺癌之间，3例边缘相对清楚；同邻近胸大肌密度相比较，9例病灶呈略低密度，2例与胸大肌密度接近，CT值39.6～53.3 Hu，平均42.5 Hu；11例病灶内部均未见明显坏死、囊变，9例病灶内见形态及走行相对正常的“空气支气管征”，其中3例内部同时伴有小囊腔；7例CT增强检查，均呈轻～中度较均匀强化，CT值50.5～85.7 Hu，平均66.1 Hu；5例病灶内见“血管漂浮征”；11例病灶均未见明显胸腔积液，2例病灶邻近胸膜增厚，2例伴有纵隔内淋巴结肿大。结论单发肺炎实变型肺MALT淋巴瘤CT上往往表现为肿瘤样的实变、炎症样模糊边缘，多轻、中度较均匀强化，内部常有固有结构的残留，部分可见“空气支气管征”及“血管漂浮征”。MSCT对该肿瘤的的诊断及鉴别具有一定价值。     

实时三维经食管超声心动图诊断人工机械瓣卡瓣的应用价值

目的探讨实时三维经食管超声心动图（RT-3D-TEE）诊断人工机械瓣卡瓣的临床应用价值。方法回顾性分析10例经手术证实为人工机械瓣卡瓣患者的RT-3D-TEE资料,其中二尖瓣位7例,主动脉瓣位3例。结果机械瓣开放幅度明显减小8例;人工机械瓣呈固定半开放状态2例,瓣口流速增快并有中量反流;见低回声附着于瓣环5例,4例瓣环处见稍高回声赘生物,1例瓣柱结构模糊。手术证实血栓形成6例,肉芽组织增生2例,伴有纤维组织侵入1例,人工机械瓣瓣柱断裂1例。结论RT-3D-TE可对人工机械瓣卡瓣及其原因进行较准确评价。     

玻璃体切除术治疗球内异物并发感染性眼内炎护理体会

球内异物并发感染性眼内炎的发生率为2.9%~13.3%[1]，一旦发生，若不及时采取有效措施，常导致视力严重下降，甚至眼球丧失等严重后果。由于血眼屏障的存在，全身或眼周使用的抗生素在玻璃体腔内很难及时达到有效浓度，无法杀灭病原菌，炎症常难以控制[2]。玻璃体切除手术可迅速清除球内异物、眼内病原微生物、毒性产物及其赖以生存的玻璃体，是目前治疗感染性眼内炎的最有效治疗方法[3]。近年来，我院采用玻璃体切除术治疗球内异物并发感染性眼内炎患者18例，取得了良好的效果，现报道如下。     

超声检查在鼻咽癌放疗后颈动脉损伤中的应用价值

目的探讨超声检查在鼻咽癌放疗后颈动脉损伤中的应用价值。方法接受放疗并随访2年以上的鼻咽癌患者40例作为放疗组，对照组30例为新诊断还未实施放疗的鼻咽癌患者，应用彩色多普勒超声检查，记录患者颈动脉狭窄部位和狭窄程度，主要检测指标有：颈动脉管腔内径，内膜-中层厚度，斑块部位、大小、形态、回声及颈动脉血流情况，同时分析两组间相关危险因素对疾病的影响。结果两组间相关危险因素如年龄、性别、高血压、高脂血症、高血糖、吸烟等差异均无统计学意义（均P＞0.05），但两组间颈动脉损伤发生率差异有统计学意义（P＜0.05）。放疗组患者内膜-中层厚度明显大于对照组，发生狭窄情况远远高于对照组。颈动脉狭窄率＞50%仅见于放疗组。结论鼻咽癌患者放疗可导致颈动脉的内膜-中层厚度增加、形成斑块继而发生狭窄，而超声检查在颈动脉损伤的早期发现、早期预防及术后疗效评估中具有重要的临床应用价值。     

MR动态增强联合扩散加权成像技术在乳腺疾病诊断中的价值

目的探讨乳腺MR动态增强扫描联合扩散加权成像技术在乳腺疾病影像诊断中的价值。方法对48例女性乳腺患者进行MRI检查,先进行双侧乳腺常规MRI平扫,再进行双侧乳腺扩散加权平面回波（EPI）序列扫描,最后行乳腺动态增强扫描。通过后处理,得到病灶处表观弥散系数（ADC）值及时间-信号强度曲线。结果根据时间-信号强度曲线特点及ADC值,结合常规MRI形态学特点进行良、恶性病变诊断。MRI诊断为恶性肿瘤19例,良性病变29例。手术或活检病理结果证实MRI诊断为恶性肿瘤的19例患者中,18例为恶性肿瘤,另外1例为良性肿瘤（旺炽性腺瘤）;MRI诊断为良性病变的29例患者,手术或病理活检均证实为良性病变。MRI区分乳腺良、恶性病变的准确率为97.9%（47/48）,与手术或病理活检准确率（100%）比较差异无统计学意义（字2=0.044,P=0.834）。结论动态增强扫描联合扩散加权成像技术,可提高乳腺疾病影像诊断准确率。     

3.0T 磁共振血管成像诊断颅内动脉成窗畸形的临床应用

目的 探讨3.0T 磁共振血管成像（MRA）诊断颅内动脉成窗畸形（FIA）的临床应用价值，了解FIA 的MRA 表现、好发部位以及临床特征。方法 回顾性分析2012 年4 月至2014年12 月共78例FIA 患者的血管畸形好发部位、类型及其合并其它颅内血管性病变的情况。78例患者均行MRA 扫描，再将原始图像经AW4.5 工作站采用最小密度投影（MIP）及三维容积重建（VR）两种方法进行血管重组，并对血管图像进行后处理。结果78例FIA 患者中，单发61 例，多发17 例，共计95 处。其中61 例单发病例中位于基底动脉15 例，位于前交通动脉区13 例，位于大脑前动脉26 例，位于大脑中动脉5例，位于大脑后动脉2 例；17 例多发病例中，位于基底动脉及左大脑前动脉6例，位于左椎动脉颅内段及左大脑前动脉7 例，位于基底动脉及前交通动脉4 例。78 例患者中合并其它颅内血管性病变者占83.3%（65/78），双侧动脉对比一侧优势者36 例，伴动静脉畸形（AVM）1 例，永存三叉动脉3例，大脑前动脉A1 段缺失16 例，血管狭窄9例。结论 3.0T MRA 能清楚显示FIA 的位置、形态及合并颅内其它血管病变的情况，是诊断FIA 的首选、有效、无创的影像检查方法。     

超声造影在结节性甲状腺肿背景下良恶性结节鉴别诊断中的应用价值

目的探讨超声造影在结节性甲状腺肿背景下良、恶性结节鉴别诊断中的应用价值。方法对结节性甲状腺肿疾病中的105个可疑结节均进行超声造影检查,分析其增强特点,所有病灶均经手术病理结果证实。结果恶性结节主要呈低增强（44.8%,30/67）,良性结节主要呈等增强（39.5%,15/38）,差异有统计学意义（P＜0.05）;良、恶性结节均以不均匀增强表现为主（60.5%、68.7%）,差异无统计学意义（P＞0.05）。恶性结节主要呈慢进同出（62.7%,42/67）,良性结节主要呈同进同出（50%,19/38）,差异具有统计学意义（P＜0.01）。结论超声造影对鉴别结节性甲状腺肿背景下良、恶性结节有一定的诊断价值。     

Minimal triangulations for an infinite family of lens spaces

The notion of a layered triangulation of a lens space was definedby Jaco and Rubinstein, and unless the lens space is L(3,1),a layered triangulation with the minimal number of tetrahedrawas shown to be unique and termed its minimal layered triangulation.This paper proves that for each n 2, the minimal layered triangulationof the lens space L(2n, 1) is its unique minimal triangulation.More generally, the minimal triangulations (and hence the complexity)are determined for an infinite family of lens spaces containingthe lens space of the form L(2n, 1). Received May 16, 2008.     

局部晚期直肠癌新辅助调强放化疗后腹腔镜手术I 期研究

目的 评估局部晚期直肠癌新辅助调强放化疗后腹腔镜手术的安全性及有效性。方法 选择24例病理确诊II～III 期的直肠腺癌患者,原发病灶及转移淋巴结外放1cm 予放疗,剂量55Gy,每次2.2Gy,盆腔放疗剂量为45Gy,每次1.8Gy。卡培他滨化疗按每日500、750、1 000、1 250、1 650、1 800 及2 000 mg/m2 共7 个剂量梯度（每个梯度3 例）爬坡进行,于放疗d1-14 及d22-35口服。观察患者的剂量限制性毒性。放化疗后6～8 周内行腹腔镜下直肠癌全系膜切除术。结果 在卡培他滨第1 至第4 剂量梯度未见剂量限制性毒性出现。在第5 剂量梯度组中1 例出现3 级腹泻,新入组3例患者无剂量限制性毒性发生。在第6剂量梯度,2 例患者分别出现3级腹泻和3级放射性皮炎,故第5梯度卡培他滨剂量[1 650mg/（m2·d）]被推荐为进一步研究使用剂量。24 例患者手术均达R0切除,5 例（20.8%）到达病理完全缓解。术后出现会阴部感染及肠梗阻各1 例,术后30d无死亡病例。结论 直肠癌新辅助调强放化疗后腹腔镜手术治疗安全有效,推荐新辅助治疗中卡培他滨剂量为1 650mg/（m2·d）。     

Cartesian powers of 3-manifolds

Previous results of the authors completely determine when the n-fold self-products of two 3-dimensional lens spaces are diffeomorphic; in particular, if n is odd then the fundamental group determines the diffeomorphism type. We prove that for all other irreducible geometric 3-manifolds with trivial first Betti number, the n-fold products of such manifolds with themselves are homeomorphic for some n?2 if and only if the manifolds themselves are homeomorphic and obtain partial results for other cases. The proofs use an assortment of techniques from 3-dimensional topology and group theory.     

Existence, Uniqueness, and Construction of the Solution of a System of Ordinary Functional Differential Equations, with Application to the Design of Perfectly Focusing Symmetric Lenses

In the design of perfectly focusing symmetric lenses, one isled, in a natural way, to a set offunctional differential equations;that is, differential equations involving composites of unknownfunctions, with initial conditions prescribed on the lens axis.This paper concentrateson those features of the equations whichmake them uniquely solvable. They are: (i) a contractivenessproperty of the equations near the axis; (ii) a uniform retardationin the arguments of thecomposite functions away from the axis.The second and third sections of this paper generalize and formalizethese properties and provide proofs of existence, uniqueness,and continuous dependence on the data for solutions of suchgeneralized systems of functional differential equations. Becauseof the lens context which motivates our study, the problem inwhich the contractiveness property (i) above holds is calledthe ‘local’ problem, and the problem in which thearguments of composite functions are uniformly retarded is calledthe ‘global’ problem. In the final section of thepaper we apply the general results of the preceding sectionsto prove existence and uniqueness of perfectly focusing symmetriclenses up to distances from the lens axis at which various typesof breakdown, discussed in the text, may occur.     

Boundary integral equation method of higher computational accuracy

The boundary integral equation method presented in the paper features the following: (1) no singular kernels, strong or weak, are involved, and computationally no local “element” approximations are needed; (2) the integral equations are well conditioned, including the cases of bounded and multiply connected regions, and no iterative approximations are involved; (3) no post-solution differentiation is involved. These features provide for a higher computational efficiency. The method solves in full a number of engineering problems, and can be used for the stiffness matrix formulation in more complex situations.     

Comparison of methods for ordinal lens opacity data from atomic-bomb survivors: univariate worse-eye method and bivariate GEE method using global odds ratio

In analyses of bivariate ordered polytomous cataract data from atomic-bomb survivors, we compared two methods, the univariate worse-eye method, and the bivariate generalized estimating equations (GEE’s) method using global odds ratio by Williamson et al. (Journal of the American Statistical Association, 90, 1432–1437, 1995). When the association was large and only subject level covariates were used, model selection in the univariate and bivariate methods resulted in the same mean model and similar risk estimates. We showed that the mean parameter and the standard error (SE) in the univariate model are emphasized relative to those in the bivariate model, the biases of which are negligible when the association between both eyes is large. Large sample simulation studies indicated that the univariate Wald statistics are slightly conservative. The simulations also showed that, in bivariate cases, irrespective of the degree of association, the independence estimating equations method with robust SE, and the GEE method with model-based and robust SE are almost fully efficient in parameter estimation when only subject level covariates are included in the mean.     

BIFURCATIONS OF LIMIT CYCLES FORMING COMPOUND EYES IN THE CUBIC SYSTEM

Let H(n)be the maximal number of limit cycle of planar real polynomial differentialsystem with the degree n and C_m~k denote the nest of k limit cycles enclosing m singular points.By computing detection functions,tne authors study bifurcation and phase diagrams in theclass of a planar cubic disturbed Hamiltonian system.In particular,the following conclusionis reached:The planar cubic system(E_ε)has 11 limit cycles,which form the pattern ofcompound eyes of C_9~1(?)2[C'~ε(?)(2C_1~2)and have the symmetrical structure;so the Hilbertnumber H(3)≥11.     

Diffraction of light bv two parallel superposed supersonic waves,one being the second harmonic,the other the third harmonic of the same fundamental. Description of two methods leading to approximate solutions in finite form

The diffraction of light by superposed parallel ultrasonic waves, with frequency ratio 2:3, is solved by the NOA-method (N?th order approximation method). Explicit calculations of the intensities are given forN = 2. The same problem is also treated with the SA-method (method of successive approximations). The latter results are improved by iteration. In both methods the general symmetry property of the diffraction pattern is verified, namely, that symmetry with respect to the zero order occurs when the phase-difference of the supersonic waves δ = (2k + 1) π/4.