3D Isotropic Super-resolution Prostate MRI Using Generative Adversarial Networks and Unpaired Multiplane Slices

We developed a deep learning–based super-resolution model for prostate MRI. 2D T2-weighted turbo spin echo (T2w-TSE) images are the core anatomical sequences in a multiparametric MRI (mpMRI) protocol. These images have coarse through-plane resolution, are non-isotropic, and have long acquisition times (approximately 10–15 min). The model we developed aims to preserve high-frequency details that are normally lost after 3D reconstruction. We propose a novel framework for generating isotropic volumes using generative adversarial networks (GAN) from anisotropic 2D T2w-TSE and single-shot fast spin echo (ssFSE) images. The CycleGAN model used in this study allows the unpaired dataset mapping to reconstruct super-resolution (SR) volumes. Fivefold cross-validation was performed. The improvements from patch-to-volume reconstruction (PVR) to SR are 80.17%, 63.77%, and 186% for perceptual index (PI), RMSE, and SSIM, respectively; the improvements from slice-to-volume reconstruction (SVR) to SR are 72.41%, 17.44%, and 7.5% for PI, RMSE, and SSIM, respectively. Five ssFSE cases were used to test for generalizability; the perceptual quality of SR images surpasses the in-plane ssFSE images by 37.5%, with 3.26% improvement in SSIM and a higher RMSE by 7.92%. SR images were quantitatively assessed with radiologist Likert scores. Our isotropic SR volumes are able to reproduce high-frequency detail, maintaining comparable image quality to in-plane TSE images in all planes without sacrificing perceptual accuracy. The SR reconstruction networks were also successfully applied to the ssFSE images, demonstrating that high-quality isotropic volume achieved from ultra-fast acquisition is feasible.

     

多种维生素及微量元素对高温致神经管畸形的保护作用及其对纤维粘连蛋白和层粘连蛋白mRNA表达的影响

目的:探讨高温致神经管畸形(NTD)的因素及多种维生素和微量元素对NTD的保护作用。方法:实验孕鼠随机分为A组(孕前第8天开始灌服多种维生素及微量元素)、B组(孕后第1天开始灌服)和C组(不灌服)孕鼠高温处理。对各组胎鼠进行形态学观察,记录NTD发生率;用原位杂交技术检测纤维粘连蛋白(FN)和层粘连蛋白(LN)在神经上皮细胞及其周围间充质中的转录状况。结果:(1)各组鼠胚均出现不同类型的NTD,C组NTD发生率最高,为77.5%。(2)各组鼠胚神经上皮细胞及其周围间充质中见FN和LN mRNA阳性转录信号,C组明显弱于其他组。结论:FN和LN转录降低是NTD发生的重要因素之一,多种维生素及微量元素对高温致NTD有一定的保护作用。     

Effects of preservation time on proliferative potential of human limbal stem/progenitor cells

AIM: To determine the proliferative potential and the maintenance of stem cell activity in stored human limbal tissues, and correlate this with the preservation time, cell viability and the expression of stem cell markers.METHODS: Thirty limbal rims were split into 4 parts and stored in corneal preservation medium at 4℃ for 0, 1, 4, or 7 days. The limbal stem cell and mitotic markers P63, CK19, proliferating cell nuclear antigen (PCNA), and Ki67 were determined by immunohistochemical staining. The proliferative potential of limbal epithelial cells was assessed by cell viability, the ability of generating stratified epithelium, and colony forming assay.RESULTS: The stored tissues maintained limbal stratified structure to 7 days and exhibited comparable expression level of stem cell and mitotic markers. The proportion of viable cells decreased with the prolonged preservation time, while colony forming efficiency decreased from the 1^st day and disappeared at the 4^th day. When inoculated on amniotic membrane, the cells preserved for 1 day formed a stratified epithelium, while the cells from 4 days’ preservation formed a discontinuous layer.CONCLUSION: The colony forming efficiency of limbal epithelial stem/progenitor cells decreased rapidly with the increasing preservation time, while the expression level of markers and capacity of forming epithelial monolayer on amniotic membrane decreased gradually. The limbal epithelial stem cells lost their function earlier than the lost expression level of stem cell markers. This may help us to better choose the appropriate preservation grafts for future limbal stem cell transplantation.     

超声刀在开放性原发性甲亢手术中的应用价值

目的 探讨超声刀在开放性原发性甲亢手术中的应用价值.方法 收集我院2007年8月至2010年10月我院同一手术小组完成的原发性甲亢手术47例,包括超声刀手术25例(超声刀组),传统手术(传统组)22例.比较两组的手术时间、术中出血量、腺体切除量、切口长度、术后引流量和术后并发症情况.结果 超声刀组手术时间(55.40±3.32)min,传统手术组(93.73±4.39)min,平均缩短38.33 min,两组差异有统计学意义(P<0.05),超声刀组术中出血量(10.32±1.86)ml,传统手术组(48.95±4.43)ml,平均减少38.63 ml,两组差异有统计学意义(P<0.05),超声刀组手术切口(4.92±0.64)cm,传统手术组(10.14±0.83)cm,平均缩短5.22 cm,两组差异有统计学意义(P<0.05),其余各项指标均无统计学差异(P>0.05).结论 应用超声刀行原发性甲亢手术,安全可靠,可明显缩少手术时间,减少术中出血量,缩小手术切口.     

超声刀在甲状腺开放性手术中的应用体会

目的探讨超声刀在开放性甲状腺手术中的应用价值。方法收集我院2008年8月至2010年5月同一手术小组完成的甲状腺手术430例,包括超声刀手术(超声刀组)230例,传统手术(传统组)200例。比较两组的手术时间、术中出血量、腺体切除量、切口长度、术后引流量和术后并发症情况。结果超声刀组手术时间为(51.94±3.84)min,传统手术组为(90.88±4.55)min,平均缩短38.94min,两组比较差异有统计学意义(P<0.05),超声刀组术中出血量为(10.20±1.49)ml,传统手术组为(44.90±4.78)ml,平均减少34.70ml,两组比较差异有统计学意义(P<0.05),超声刀组手术切口位(4.21±0.86)cm,传统手术组为(9.76±1.10)cm,平均缩短5.55cm,两组比较差异有统计学意义(P<0.05),其余各项指标比较差异均无统计学意义(P>0.05)。结论应用超声刀行开放性甲状腺手术安全可靠,可明显缩少手术时间,减少术中出血量,缩小手术切口。     

Theoretical investigation on the nature of 4-substituted Hantzsch esters as alkylation agents

Recently, a variety of 4-substituted Hantzsch esters (XRH) with different structures have been widely researched as alkylation reagents in chemical reactions, and the key step of the chemical process is the elementary step of XRH˙⁺ releasing R˙. The purpose of this work is to investigate the essential factors which determine whether or not an XRH is a great alkylation reagent using density functional theory (DFT). This study shows that the ability of an XRH acting as an alkylation reagent can be reasonably estimated by its ΔG^≠_RD(XRH˙⁺) value, which can be conveniently obtained through DFT computations. Moreover, the data also show that ΔG^≠_RD(XRH˙⁺) has no simple correlation with the structural features of XRH, including the electronegativity of the R substituent group and the magnitude of steric resistance; therefore, it is difficult to judge whether an XRH can provide R˙ solely by experience. Thus, these results are helpful for chemists to design 4-substituted Hantzsch esters (XRH) with novel structures and to guide the application of XRH as a free radical precursor in organic synthesis.

This work presents a convenient computation method to estimate whether a 4-substituted Hantzsch ester can be a good alkyl radical donor.     

微山湖区放养子代钉螺生殖腺透射电镜观察

目的观察在微山湖区螺笼放养12个冬季、繁殖12代的成年钉螺睾丸、卵巢形态变化。方法以亲代来源于长江扬州段的微山湖子代成年钉螺为实验组,以长江扬州段江滩阴性成年钉螺为对照组,解剖两组钉螺获得完整的睾丸和卵巢标本。以常规方法固定、脱水、包埋标本,烘箱内聚合,用超薄切片机常规切片,取切片在透射电子显微镜下拍照和观察,比较两组钉螺生殖腺超微结构。结果对照组钉螺精子细胞尾部横切面可见"9+2"微管结构,头端可见三角形顶体和呈螺旋形且致密的核质;实验组钉螺精子细胞尾部横切面"9+2"微管结构消失,头端染色质密度稀疏。对照组钉螺卵巢卵细胞核仁、核膜清晰,细胞质内可见卵黄体、脂质体、内质网,核膜为双层曲折,核仁均匀;实验组钉螺卵巢卵细胞核膜光滑,核仁不明显,细胞内含物更加稀疏。结论经过12个冬季放养,钉螺不能完全适应中国北方的自然环境,其生殖腺超微结构发生了明显变化,这可能是微山湖区放养钉螺逐步减少甚至趋于消亡的原因之一。     

Predicting quality of life after breast cancer surgery using ANN-based models: performance comparison with MR

Purpose

The goal was to develop models for predicting long-term quality of life (QOL) after breast cancer surgery.

Methods

Data were obtained from 203 breast cancer patients who completed the SF-36 health survey before and 2 years after surgery. Two of the models used to predict QOL after surgery were artificial neural networks (ANNs), which included one multilayer perceptron (MLP) network and one radial basis function (RBF) network. The third model was a multiple regression (MR) model. The criteria for evaluating the accuracy of the system models were mean square error (MSE) and mean absolute percentage error (MAPE).

Results

Compared to the MR model, the ANN-based models generally had smaller MSE values and smaller MAPE values in the test data set. One exception was the second year MSE for the test value. Most MAPE values for the ANN models ranged from 10 to 20 %. The one exception was the 6-month physical component summary score (PCS), which ranged from 23.19 to 26.86 %. Comparison of criteria for evaluating system performance showed that the ANN-based systems outperformed the MR system in terms of prediction accuracy. In both the MLP and RBF networks, surgical procedure type was the most sensitive parameter affecting PCS, and preoperative functional status was the most sensitive parameter affecting mental component summary score.

Conclusion

The three systems can be combined to obtain a conservative prediction, and a combined approach is a potential supplemental tool for predicting long-term QOL after surgical treatment for breast cancer.

Relevance

Patients should also be advised that their postoperative QOL might depend not only on the success of their operations but also on their preoperative functional status.