Parallel imaging reconstruction for arbitrary trajectories using k-space sparse matrices (kSPA).

Although the concept of receiving MR signal using multiple coils simultaneously has been known for over two decades, the technique has only recently become clinically available as a result of the development of several effective parallel imaging reconstruction algorithms. Despite the success of these algorithms, it remains a challenge in many applications to rapidly and reliably reconstruct an image from partially-acquired general non-Cartesian k-space data. Such applications include, for example, three-dimensional (3D) imaging, functional MRI (fMRI), perfusion-weighted imaging, and diffusion tensor imaging (DTI), in which a large number of images have to be reconstructed. In this work, a systematic k-space-based reconstruction algorithm based on k-space sparse matrices (kSPA) is introduced. This algorithm formulates the image reconstruction problem as a system of sparse linear equations in k-space. The inversion of this system of equations is achieved by computing a sparse approximate inverse matrix. The algorithm is demonstrated using both simulated and in vivo data, and the resulting image quality is comparable to that of the iterative sensitivity encoding (SENSE) algorithm. The kSPA algorithm is noniterative and the computed sparse approximate inverse can be applied repetitively to reconstruct all subsequent images. This algorithm, therefore, is particularly suitable for the aforementioned applications.     

正大维他和维伦滴眼液治疗眼表疾病的疗效

干眼和眼表疾病为眼科最常见疾病。本文报告包括干眼症在内的各种眼表疾病６８例１００眼，应用正大维他和维伦滴眼液治疗，获得良好的疗效。在这些滴眼液内含有玻璃酸钠粘多糖类粘性增强剂，可延长药液在角膜前表面的仪时间和增强药效。在治疗中未出现任何副作用。     

Deltoid flap combined with fascia lata autograft for rotator cuff defects: a histologic study

The purpose of this study was to compare the histological characteristics of an autogenous fascia lata graft alone and a fascia lata graft combined with a deltoid flap in the reconstruction of rotator cuff tears. Ten New Zealand white rabbits were divided into two groups. Infraspinatus tendon defects (1 × 1 cm) were created in each animal. Reconstruction consisted of either a fascia lata graft alone or a fascia lata graft combined with a distally based deltoid flap. At 3 months, tissue harvest and histological analysis was performed. Compared to the fascia lata graft alone, there was significantly increased remodeling activity and neovascularization in the group that included a deltoid flap. Also, there was pronounced interdigitation at the graft/flap interface in the latter group. A mutually beneficial relationship may exist when an autogenous fascial graft is combined with a functional deltoid flap for reconstructing large rotator cuff defects.     

关节镜下肩袖缝合术治疗肩袖撕裂

目的探讨关节镜下肩袖缝合术治疗肩袖撕裂的手术方法和临床效果。方法2002年12月至2005年10月，对27例肩袖撕裂患者行关节镜下肩袖缝合术，25例获得1年以上随访，其中男12例，女13例；年龄35～67岁，平均54．3岁；左肩6例，右肩19例，涉及优势侧19例。10例滑囊侧部分撕裂，1例滑囊侧及关节侧均有部分撕裂，14例全层撕裂。术前均拍摄肩关节正位和冈上肌出口位X线片，21例行B超检查，23例行MR或MRA检查。全部病例行肩峰下滑囊切除及前肩峰成形术。肩袖修复方式：1例直接行断端缝合，15例应用缝合锚钉行肩袖止点重建，9例联合应用断端缝合及缝合锚钉技术。分别在术前和最终随访时采用UCLA肩关节评分标准进行评价。结果随访时间1～3年，平均23个月。术后平均UCLA评分为（32．3±t2．3）分。手术前后疼痛评分平均为（2．6±t0．9）分和（8．6±1．4）分（P=0．000），功能评分平均为（5．0±1．8）分和（9．1±1．0）分（P=0．000），肩关节主动前屈评分平均为（3．6±1.5）分和（4．9±10.3）分（P=0．000），前屈肌力评分平均为（4．0±0．6）分和（4．7±0．5）分（P=0．000），差异均有统计学意义。优8例、良17例，所有患者均对手术效果表示满意。结论关节镜下肩袖缝合术是治疗肩袖撕裂的有效方法。术中应有效地控制出血，适度进行肩峰成形，正确识别撕裂的形状，充分松解粘连并采用恰当的缝合方式。手术创伤小、恢复快，其疗效可达到切开手术水平。     

Single-equation models for the tear film in a blink cycle: realistic lid motion.

We consider model problems for the tear film over multiple blink cycles that utilize a single equation for the tear film; the single non-linear partial differential equation that governs the film thickness arises from lubrication theory. The two models that we consider arise from considering the absence of naturally occurring surfactant and the case when the surfactant is strongly affecting the surface tension. The film is considered on a time-varying domain length with specified film thickness and volume flux at each end; only one end of the domain is moving, which is analogous to the upper eyelid moving with each blink. Realistic lid motion from observed blinks is included in the model with end fluxes specified to more closely match the blink cycle than those previously reported. Numerical computations show quantitative agreement with in vivo tear film thickness measurements under partial blink conditions. A transition between periodic and non-periodic solutions has been estimated as a function of closure fraction and this may be a criterion for what is effectively a full blink according to fluid dynamics.     

Pathological analysis of hypertrophic cardiomyopathy simulating dilated cardiomyopathy

The pathomorphologic features of hypertrophic cardiomyopathy simulating dilated cardiomyopathy in the late stage (HCM-DCM) were compared with those of ordinary hypertrophic cardiomyopathy (HCM). Seven autopsied hearts with HCM-DCM and 11 with HCM were assessed quantitatively using an image analyzer. Unlike HCM, significant left ventricular enlargement and wall thinning were observed in HCM-DCM, and the percentage areas of massive fibrosis and disarray were significantly greater. In HCM-DCM, the disarray was distributed diffusely, whereas massive fibrosis was distributed more intensively in the ventricular septum and anterior wall than in the lateral and posterior wall. Narrowing of intramyocardial small arteries was observed more frequently in HCM-DCM, especially in the ventricular septum and anterior wall, than in HCM. These results suggest that the enlargement and wall thinning of the left ventricle in HCM-DCM are attributable to non-uniform progression of massive fibrosis, which is closely related to small-arterial lesions.     

巨大裂孔性视网膜脱离的手术治疗

目的 :探讨巨大裂孔性视网膜脱离有效治疗方法。方法 :根据病情的不同 ,对巨大裂孔性视网膜脱离 2 1例 2 1眼选择环扎术、冷冻、外加压或玻璃体切除术、视网膜前膜剥离、切除、视网膜切开、切除、眼内氩激光封闭视网膜裂孔。部分病例采用气液交换平复视网膜。术后眼内充填 C3F8或硅油。结果 :随访 3～ 12个月 ,视网膜最终复位 18眼 ,3眼未复位。手术成功率 86% (18/ 2 1)。结论 :采取适当的联合手术方法 ,能提高巨大裂孔性视网膜脱离治愈率。氟碳液的应用 ,简便了手术操作 ,提高了成功率     

Inhibition of Smad3 promotes the healing of rotator cuff injury in a rat model

To investigate the effect of inhibiting transforming growth factor‐β (TGF‐β1)/Smad2/3 signaling on rotator cuff (RC) healing. A bilateral supraspinatus tendon detachment‐repair model of Sprague‐Dawley (SD) rats was utilized. A total of 120 SD rats were randomly assigned to six groups and each group received the subacromial injection of normal saline, empty vectors, or lentiviral vectors containing small interfering RNA against TGF‐β1, Smad2, Smad3 at the bone‐tendon junction. Biomechanical and histological analyses were performed to evaluate bone‐tendon junction healing quality at 8 weeks after repair. Histologically, scar healing was found in all surgical groups. Animals with inhibited Smad3 exhibited better bone‐tendon junction structures with higher density, parallel orientation, and collagen fiber continuity than other surgical group animals. Immunohistochemistry revealed that the protein expression level of collagen I in animals with inhibited Smad3 was more prominent compared with all other surgical groups. Biomechanically, Animals with inhibited Smad3 showed better results in the maximum load at 4, 6, and 8 weeks after surgery compared with other surgical groups. Besides, C3H10T1/2 (Smad3?) cells increased TT‐D6 cell migration and tendon‐associated genes expression (scleraxis, tenascin C, collagen I) in coculture system. We conclude that inhibition of Smad3 promotes RC tendon healing in the rat supraspinatus model.