局麻下口内入路双侧颧骨和下颌角截骨矫正方形脸畸形

目的：探讨双侧颧骨和下颌角截骨矫正方形脸畸形的手术效果。方法：针对颧骨和下颌角肥大引起的方形脸畸形，采用局部浸润麻醉、口内入路、双侧颧骨和下颌角截骨手术方法，一次或分二次手术矫正。结果：2003～2006年共施术25例，一次手术12例，二次手术13例。随访6～24个月，所有病例伤口愈合好，外观改善满意，无一例发生骨折、神经损伤、感染、大出血等并发症。结论：局麻下口内入路双侧颧骨和下颌角截骨矫正方形脸畸形手术方法设计合理、操作简便、并发症少，术后效果良好。     

前方牵引治疗安氏Ⅲ类骨性反最佳矫治时机的研究

目的:进一步探寻前牵矫治器对以上颌发育不足为主的安氏Ⅲ类骨性反患者的最佳矫治时机。方法:选取45例研究对象分成3组,即3~6岁组、7~10岁组、11~13岁组,每组各15例;采用上颌前方牵引进行治疗,拍摄治疗前后的头颅定位侧位片进行X线头影测量分析。结果:上颌前方牵引治疗对上述3个试验组的患者均产生了一定的矫治效果;上颌骨前移,下颌骨后旋,前牙反纠正、覆合覆盖达正常、磨牙关系达中性关系;3组研究对象对比显示年龄最小的3~6岁组相对后两组具有更短的治疗时间(3.8±0.4)个月、更多的骨骼改变(69.5%)、更少的牙齿改变(31.5%)以及更少的副作用等优点(P<0.05);11~13岁组相对前两组治疗时间较长(9±0.5)个月、骨骼改变较少(59.5%)牙齿的代偿性改变较多(41.0%,P<0.05)。结论:前牵引治疗安氏Ⅲ类骨性反矫治时机的选择在3~6岁组比7~10岁组效果好;7~10岁组比11~13岁组效果好。     

Intuitive design guidelines for fast spin echo imaging with variable flip angle echo trains.

We present a simple and intuitive means for determining the flip angles (FAs) required for smooth transitions between static pseudo steady states (SPSSs) in fast spin echo (FSE) imaging with variable FA (VFA) echo trains. We demonstrate the effectiveness of single and multiple transition pulses to successfully vary refocusing FAs while retaining high signal levels. The graphical interpretation presented here is consistent with previous analytical techniques and permits accurate signal-intensity predictions along the echo train.     

水平骶椎的临床X线分析

目的分析水平骶椎的影像表现。方法12例临床怀疑水平骶椎患者(男2例,女10例;年龄23～25岁)均摄腰骶椎正侧位片,并在患者直立侧位片上,利用CR后处理功能测量第一骶椎上面与水平线所交的角。其中,3例又经CT检查。结果本组12例中,腰骶角在45～55°之间5例,腰骶角在56～65°之间6例,腰骶角在66°以上1例。腰骶正位片示骶骨投影变短,结构重叠,腰骶侧位片示腰骶部极度侧弯。CT片上有椎间盘突出2例,椎间盘膨出3例,以及椎骨狭窄2例。结论侧位片上腰骶部极度侧弯和腰骶角大于45°是水平骶椎的特征性X线表现。CT扫描可发现一些继发病变。     

The optometric role in angle closure glaucoma

Primary angle closure glaucoma (PACG) is not a rare disease, nor is it always readily diagnosed. Patients having primary angle closure glaucoma present with a spectrum of severity from symptomless through to a very dramatic form. This review describes the pathophysiology of angle closure and details the signs and symptoms of the disease in its various forms. Optometric management strategies are suggested for the diagnosis and management of the disease and current ophthalmological treatment is also outlined.     

开角型与闭角型青光眼色觉异常的对比研究

采用FM100－色彩有试验，对开角型与闭角型青光眼色觉损害的情况进行了对比观察，结果发现，两类青光眼色彩分辨力的损害，无论在波长区域或程度上，均无明显差异，认为眼压升高是引起色觉异常的始发因素，据此可以对两类青光眼色觉损害的相似性作出较为满意的解释。     

Giant aneurysm of the anterior inferior cerebellar artery simulating a cerebellopontine angle tumor

An aneurysm of the anterior inferior cerebellar artery simulating a cerebellopontine angle tumor is reported. Only 13 such cases have been published so far. The relevant literature is reviewed.     

Elbow flexor evoked twitch contractile properties in untrained men and women and male bodybuilders

Summary The influence of elbow joint angle on elbow flexor isometric evoked twitch contractile properties was assessed in 15 young women (F), 18 young men (M) and 11 male bodybuilders (BB). Measurements were made at elbow joint angles of 1.31, 1.57, 1.83, 2.09, 2.36, 2.62 and 2.88 rad (3.14 rad =180° =full extension). The largest peak twitch torque values [mean (SE) N · m] in F [3.77 (0.20)], M [10.38 (0.68)] and BB [11.38 (1.05)] occurred at 2.88 rad. Peak torque was progressively smaller at smaller joint angles, but the decline from 2.88 to 1.31 rad was greater in M (68%) and BB (76%) than F (59%). Thus, the magnitude of intergroup differences in peak twitch torque (PT) was joint angle dependent. Twitch time to peak torque (TPT) was influenced in a complex way by joint angle in the three groups; BB had the lowest values at small joint angles but the highest values at the largest angles. Half-relaxation time (HRT) generally increased from the smallest to largest joint angles in a pattern that did not differ significantly among the three groups. Maximum rates of twitch torque development and relaxation showed the same pattern of results as PT; indicating that these time-related measures were more sensitive to joint angle effects on PT than on TPT or HRT. The results of this study indicate that careful consideration should be given to the selection of joint angles in the measurement of evoked twitch contractile properties for the purpose of making group comparisons or investigating the effects of interventions such as training.     

Elimination of eddy current artifacts in diffusion-weighted echo-planar images: The use of bipolar gradients

Small gradient fields resulting from incompletely canceled eddy currents can cause geometric distortion in echo-planar images. Although this distortion is negligible in most echo-planar applications, the large gradient pulses used in diffusion-weighted echo-planar imaging can result in significant image distortion. In this report, it is shown that this distortion can be significantly reduced by the application of bipolar gradient waveforms. Both bipolar diffusion-sensitizing gradients and an inverted gradient preparatory pulse were examined for minimizing the eddy currents responsible for these distortions.     

β-PLEATED SHEETS IN OLIGOPEPTIDE CRYSTALS

Many oligopeptide crystals show the β-pleated sheet structures. Both parallel and antiparallel chain pleated sheets are found, and also both ideal (flat) and heavily twisted sheets are found. The structural parameters, such as the T (NCα-C') angles, the torsion angles (φ and ø), the fiber axis periods, the hydrogen bond lengths, and the interchain spacings, are studied. Some of them deviate signifi cantly from those proposed by Pauling & Corey (Proc. Natl. Acad. Sci. US (1953), 39, 253–256). In the heavily twisted sheets, the twists are larger than those in the globular proteins, and each two neighboring chains are almost per pendicular with each other, preserving the β-sheet type hydrogen bond system. The torsion angles in the twisted sheets are rather close to those of the poly (L-proline) II helix. It also is discussed that the (NCαC) angles sometimes deviate by almost 5° from the standard value depending on the structures of the main and side chains.