Determination of heavy metals in water using an FTO electrode modified with CeO2/rGO nanoribbons prepared by an electrochemical method

The rGO/CeO₂/FTO nanocomposite modified electrode was prepared by an electrochemical method. A simple and highly sensitive electrochemical sensing platform for electrochemical rGO and modified CeO₂ nanoribbons directly on FTO electrodes was developed. Simultaneous determination of Pb²⁺ and Cd²⁺ used the differential pulse anodic stripping voltammetry (DPASV) method. The method was simple to operate, and CeO₂ nanobelts could be obtained simultaneously by electrodeposition and reduction of GO without further processing. This is an environmentally friendly electrochemical method to obtain modified electrodes under mild conditions. The experimental results showed that the linear calibration curves of Pb²⁺ and Cd²⁺ are 1–300 and 0.2–500 μg L⁻¹, respectively. At the same time, no interference from other coexisting metal ions was found during the detection process, which proved that the modified electrode had good stability and repeatability.

The rGO/CeO₂/FTO nanocomposite modified electrode was prepared by an electrochemical method.     

Moderate Hypofractionated Helical Tomotherapy for Older Patients with Localized Prostate Cancer: Long-term Outcomes of a Phase I–II Trial

BackgroundOur previous study showed that two different regimens of moderate hypofractionated radiotherapy (HFRT) delivered with helical tomotherapy (HT) are well tolerated in older prostate cancer patients. We provide a longterm efficacy and toxicity after > 7 years of follow-up.Patients and methodsThe study recruited 33 patients from February 2009 to July 2011 (76 Gy/34F; Group-1); and 34 from July 2011 to February 2014 (71.6 Gy/28F; 50.4 Gy/25F for the risk of pelvic lymph nodes involvement (LNI) >15%; Group-2). The primary outcomes were biochemical failure (BF), biochemical failure and clinical disease failure (BCDF), progression-free survival (PFS), overall survival (OS), late genitourinary (GU) and gastrointestinal (GI) toxicity.ResultsThe average ages of two groups were 80 and 77 years and the proportions of patients with LNI > 15% were 69.7% and 73.5%, respectively. At the final follow-up in February 2020, 27.3% and 20.6% cases experienced BF, with a median time until BF of 3.3 years. A total of 38.8% patients reached primary endpoints, in which 18 deaths were reported BCDF events (45.5% vs. 32.4%, p = 0.271). There was no significant difference in 7-year PFS (68.6% vs. 74.8%, p = 0.591), BCDF (45.5% vs. 32.4%, p = 0.271) and OS (71.9% vs. 87.5%, p = 0.376) for full set analysis and for subgroup analysis (all p > 0.05). The incidence of grade ≥ 2 late GU (6.2% vs. 6.3%, p = 0.127) and GI toxicities (9.4% vs. 15.6%, p = 0.554) was comparable.ConclusionsIn older patients with localized prostate cancer, two moderate hypofractionated regimens were all well tolerated with similar, mild late toxicities and satisfactory survival, without necessity of prophylactic pelvic node irradiation.Key words: helical tomotherapy, radiation dose hypofractionation, progression-free survival, follow-up studies, prostatic neoplasms, adenocarcinoma     

Characterization of Healthcare-Associated and Community-Associated Clostridioides difficile Infections among Adults,Canada, 2015–2019

We investigated epidemiologic and molecular characteristics of healthcare-associated (HA) and community-associated (CA) Clostridioides difficile infection (CDI) among adult patients in Canadian Nosocomial Infection Surveillance Program hospitals during 2015–2019. The study encompassed 18,455 CDI cases, 13,735 (74.4%) HA and 4,720 (25.6%) CA. During 2015–2019, HA CDI rates decreased by 23.8%, whereas CA decreased by 18.8%. HA CDI was significantly associated with increased 30-day all-cause mortality as compared with CA CDI (p<0.01). Of 2,506 isolates analyzed, the most common ribotypes (RTs) were RT027, RT106, RT014, and RT020. RT027 was more often associated with CDI-attributable death than was non-RT027, regardless of acquisition type. Overall resistance C. difficile rates were similar for all drugs tested except moxifloxacin. Adult HA and CA CDI rates have declined, coinciding with changes in prevalence of RT027 and RT106. Infection prevention and control and continued national surveillance are integral to clarifying CDI epidemiology, investigation, and control.     

EXPERIMENTAL SPINAL CORD TRAUMATIC INJURY OF THE CAT TREATED WITH ELECTRO-ACUPUNCTURE

44 cats were used in this experiment. The spinal cords of 40 animals were injuredat about L_1 level by using Allen's method (400g/cm) and randomly divided into 2 groups: A)electro-acupuncture treatment group (n=20) and B) control group(n=20). 2 weeks after spinalcord injury, 80% of animals in the treatment group were survival and 45% of animals in the con-trol group were survival. There was significant difference between these two groups (p<0. 05).The motor evoked potential was recorded two weeks after spinal cord injury. The latency of theshort latency peak was 15. 61±4. 98 mS and the amplitude was 10. 61 0. 59 mV in the treatmentgroup; and 21. 7±5. 02 mS and 0. 56±0. 32 mV in the control group. Both latency and amplitudewere significant different between the two groups (P<0. 05, P<0. 05). The Anti-NF-H (neuro-filament) was determined at 2 and 4 weeks respectively after spinal cord injury. The more NF-Hpositive labeling fibers were found in the treatment group than in the control group (P<0. 01 ).The     

百蕊含片的质量标准研究

采用TLC法对百蕊含片中山柰素进行鉴别;用HPLC法测定山柰素的含量;含量限度为山柰素量不少于0．30mg/片。     

中药代谢分析研究进展＊

中药具有多成分、多靶点的特性，药效物质基础及药物代谢途径不明确严重制约中药的发展。中药小分子经过体内代谢后转化成代谢物发挥药效或者清除。近年来随着MS技术的飞速发展，通过LC-MS技术进行精准定性定量分析，以阐明中药代谢物与机体生理及病理相关变化的关系，从而明确中药的药效物质基础及体内代谢路径。本文从中药代谢研究思路、研究方法、影响因素以及应用等方面，就近年来中药代谢分析领域的研究进展进行综述。     

兔肝VX_2肿瘤模型的建立及生物学特性

目的探讨采用瘤块种植制备兔肝VX2肿瘤模型的可行性并研究其生物学特性。方法采用VX2肿瘤组织块制备兔肝肿瘤模型,观察谷丙转氨酶(ALT)、体温、体质量、体液免疫球蛋白、肿瘤的增长、脏器转移及组织病理学改变等。结果兔肝VX2肿瘤原位移植模型的移植成功率为100%,6周肝内转移率为100%,6周肺转移率为80%。随着瘤体体积的增长,体温及ALT逐渐升高,体质量逐渐减轻,免疫球蛋白则呈下降趋势。超声检查显示肝脏有结节样增强回声。肿瘤呈灰白色,质硬,光镜下可见癌细胞核大,深染伴核异型。结论采用瘤块种植制备兔肝VX2肿瘤模型,具有容易制备、生长周期短、成功率高及模型稳定等特点,是一种较理想的肝肿瘤实验动物模型。     

正常青春期少女及特发性中枢性性早熟女孩生长激素结合蛋白、性激素与生长

本文对41例青春期女孩及30例特发性中枢性性早熟(ICPP)女孩。观察其身高、体重、身高增长速度、骨龄与生长激素结合蛋白(GHBP)、雌二醇(E_2)的相关关系,结果示GHBP在青春各期间无显著差异,GHBP与身高生长速度(GV)、身高标准差分(HtsDs)、体重指数(BMI)呈正相关,GHBP与E_2、年龄(CA)、骨龄(BA)无相关关系。正常青春少女与ICPP女孩相应青春期血清GHBP无明显差异,ICPP女孩GHBP与HtsDs及BMI呈正相关关系,与E_2、CA及BA无相关关系。提示正常青春少女及ICPP女孩的生长,在GH轴调控途径上,至少在生长激素受体(GHR)/GHBP水平是相同的。GHBP受营养的正性影响,不受年龄、骨龄影响。     

表麻下小切口透明晶状体吸出及人工晶状体植入术治疗高度近视

目的 :评价高度近视患者表麻下行透明晶状体吸出及人工晶状体植入术的术后效果。方法 :5 6例 10 6眼高度近视患者在表面麻醉下行小切口透明晶状体吸出及人工晶状体植入术。使用超声乳化仪 ,但未用超声能量。平均年龄 3 8 5 9± 9 44岁 ;术前裸眼视力 0 0 1～ 0 2 ,矫正视力 0 0 5～ 1 0 ;平均近视度 (-19 47± 5 41)D ,平均眼轴长(3 0 45± 1 94)mm ,平均植入人工晶状体屈光度数 ( 3 96± 4 2 7)D。术后平均随访时间 16个月。结果 :术后裸眼视力均好于或等于术前矫正视力。术后裸眼视力≥ 0 5者 79眼 (74 5 % )。术后矫正视力≥ 0 5者 99眼 (93 4% )。术后平均屈光度 (-1 49± 1 11)D。发生后囊膜混浊及玻璃体前界膜混浊 8眼 ,无视网膜脱离及黄斑囊样水肿发生。结论 :表麻下小切口透明晶状体吸出及人工晶状体植入术矫正高度近视 ,安全有效 ,预测性好 ,视力稳定。     

不同降温速度对保存的角膜内皮细胞活性的影响

目的通过调节程序控制降温仪的降温速度保存兔角膜，以提高保存角膜的内皮细胞的存活率（ESR）。方法供体角膜150只随机分为对照组和实验组。对照组不做冷冻处理；实验组冷冻147只角膜，带巩膜缘1～2mm的角膜片分别在4种不同浓度梯度的冻存液中预处理各10min，再经过两个阶段（0～-18℃，-18～-80℃）49种不同程序逐步降温至-80℃，最后放入液氮中保存。1个月后水浴复苏供体角膜，洗脱冻存液、染色、同定，行镜下形态学观察并计算角膜内皮细胞存活率。结果镜下观察第一阶段降温速度为2℃／min、第二阶段降温速度为5℃／min时的方法较好，计数细胞的存活率达到75％以上，与其他不同速度下比较差异有统计学意义（P〈0．05）。结论不同阶段不同降温速度下，深低温保存兔角膜对角膜的内皮细胞存活率有明显影响。