机器学习在放射治疗中的临床应用

放射治疗是癌症的主要治疗手段之一,以机器学习为代表的人工智能飞速发展,可应用于放射治疗临床实践的各个环节,包括临床决策支持、自动勾画靶区、预测疗效和副反应等,提高准确性与效率.尽管面临着结构化数据缺乏、模型可解释性差等挑战,机器学习在放射治疗中的应用将日趋深刻而广泛.本文从机器学习简介、在放射治疗中的临床应用研究进展和...     

抗癌先导物T-OA在不同介质中的平衡溶解度及表观油水分配系数

目的测定抗癌先导物T-OA在不同pH（1¹0）缓冲溶液和表面活性剂溶液中的平衡溶解度,在正辛醇-水/缓冲液体系中的表观油水分配系数。方法采用高效液相法测定了T-OA在不同pH（1¹0）缓冲溶液和表面活性剂溶液中的浓度,采用摇瓶-HPLC法测定了T-OA的表观油水分配系数。结果 T-OA在37℃缓冲液中随pH的增高平衡溶解度逐渐增大,最大平衡溶解度为5.10 mg/L;在32 g/L的十二烷基硫酸钠溶液中其平衡溶解度提高到706.97 mg/L;T-OA的表观油水分配系数为544.71(Ig P_app=2.74),且随溶液pH的增高逐渐降低。结论 T-OA的水溶性较差,可采用适当浓度的十二烷基硫酸钠和吐温80作为溶出介质,这为今后的剂型选择提供了参考。     

高糖对体外培养兔视网膜Müller细胞AQP4表达的影响

目的：观察体外培养兔视网膜Müller细胞在高糖条件下水通道蛋白-4（AQP4）表达的变化。方法：采用体外培养的兔视网膜Müller 细胞,分为正常对照组及高糖组（葡萄糖浓度：30、40和50 mmol•L^-1）,分别培养1、3和5 d;采用免疫细胞化学、流式细胞术及RT-PCR方法对Müller 细胞AQP4的表达情况进行检测。结果：高糖组Müller 细胞AQP4表达的绿色荧光明显弱于正常对照组（P<0.01）;流式细胞仪检测中波峰位置明显提前,AQP4表达强度较对照组明显减弱（P<0.01）,且随着葡萄糖浓度的增高和作用时间的延长,AQP4表达强度逐渐减弱;血糖浓度50 mmol•L^-1培养3 d时,RT-PCR半定量分析显示,AQP4 mRNA的表达比对照组明显降低（P<0.01）。结论：高糖能降低视网膜Müller细胞AQP4的表达,且随着葡萄糖浓度的增高和作用时间的延长,AQP4的表达强度也逐渐减弱;高糖时AQP4的表达下降可能是机体对糖尿病视网膜病变的一种保护性反应。     

积雪草提取纯化工艺的研究

目的研究积雪草的提取纯化工艺。方法采用正交试验进行工艺优化,薄层色谱扫描法测定羟基积雪草苷含量。结果提取工艺最佳条件为:水提取2次,第1次加10倍量水提取2h,第2次加8倍量水提取1.5h。纯化工艺最佳条件为壳聚糖用量0.4mL/g,药液浓缩比例1.2:1,絮凝温度70℃。结论本方法可节省原料,缩短工时,降低成本,利于工业化大生产。     

乳腺癌改良根治术后三种放疗技术的剂量学对比研究

目的:分析比较容积调强弧形治疗(VMAT)与固定野调强放疗(F_IMRT)、电子束联合VMAT (E&VMAT)技术在乳腺癌改良根治术后放疗中的剂量学差异,为临床选择治疗方案提供参考。方法:随机选择乳腺癌改良根治术后放疗的左乳腺癌患者10例,靶区包括患侧胸壁和锁骨上淋巴引流区,处方剂量43.5 Gy (2.9 Gy/次...     

Early Impacts of a Healthy Food Distribution Program on the Availability and Price of Fresh Fruits and Vegetables in Small Retail Venues in Los Angeles

Healthy food distribution programs that allow small retailers to purchase fresh fruits and vegetables at wholesale prices may increase the profitability of selling produce. While promising, little is known about how these programs affect the availability of fresh fruits and vegetables in underserved communities. This study examined the impacts of a healthy food distribution program in Los Angeles County over its first year of operation (August 2015–2016). Assessment methods included: (1) a brief survey examining the characteristics, purchasing habits, and attitudes of stores entering the program; (2) longitudinal tracking of sales data examining changes in the volume and variety of fruits and vegetables distributed through the program; and (3) the collection of comparison price data from wholesale market databases and local grocery stores. Seventeen stores participated in the program over the study period. One-fourth of survey respondents reported no recent experience selling produce. Analysis of sales data showed that, on average, the total volume of produce distributed through the program increased by six pounds per week over the study period (95% confidence limit: 4.50, 7.50); trends varied by store and produce type. Produce prices offered through the program approximated those at wholesale markets, and were lower than prices at full-service grocers. Results suggest that healthy food distribution programs may reduce certain supply-side barriers to offering fresh produce in small retail venues. While promising, more work is needed to understand the impacts of such programs on in-store environments and consumer behaviors.     

Moderate exercise training attenuates aging-induced cardiac inflammation,hypertrophy and fibrosis injuries of rat hearts

Aging is the most important risk factor in cardiovascular disease (CVD), which is the leading causes of death worldwide and the second major cause of death in Taiwan. The major factor in heart failure during aging is heart remodeling, including long-term stress-induced cardiac hypertrophy and fibrosis. Exercise is good for aging heart health, but the impact of exercise training on aging is not defined. This study used 3-, 12- and 18-month-old rats and randomly divided each age group into no exercise training control groups (C3, A12 and A18) and moderate gentle swimming exercise training groups (E3, AE12 and AE18). The protocol of exercise training was swimming five times weekly with gradual increases from the first week from 20 to 60 min for 12 weeks. Analyses of protein from rat heart tissues and sections revealed cardiac inflammation, hypertrophy and fibrosis pathway increases in aged rat groups (A12 and A18), which were improved in exercise training groups (AE12 and AE18). There were no heart injuries in young rat hearts in exercise group E3. These data suggest that moderate swimming exercise training attenuated aging-induced cardiac inflammation, hypertrophy and fibrosis injuries of rat hearts.