面向L5/S1微创椎间盘射频消融术的多约束最优穿刺路径规划算法

目的为有效减少L5/S1微创椎间盘射频消融术中因医师操作熟练度差异导致的治疗效果波动,实现对消融针穿刺路径风险的精确量化评估。方法基于自主研发的深度神经网络DWT-UNet,将L5/S1节段的MR图像精准分割为7个关键结构:L5椎骨,S1椎骨,髂骨,L5/S1节段的椎间盘、神经根、硬脊膜和皮肤。基于上述分割结果,3D建模穿刺路径的规划环境。针对穿刺的临床准则提出了6个硬性约束和6个软性约束,将医师经验通过层次分析算法量化为权重添加到穿刺路径风险函数中以提升对个例的适应性。通过提出的皮肤进针点采样子算法、Kambin三角投影面积子算法,结合层次分析算法,并运用光线追踪、CPU多线程处理和GPU并行计算等多种技术,计算出一条既符合临床硬性约束条件,又能使软性约束条件综合达到最优的穿刺路径。结果医师团队对算法规划的21例消融针穿刺路径进行主观评估,结果显示所有路径均满足临床基本要求(及格率100%),且95.24%的路径被评为优秀或良好。在与医师规划结果的对比中,算法在D_(Ilium)、D_(S1)和Depth等3个指标上有不同程度的下降(P<0.05),在D_(Dura)、D_(L5)、D_(N5)和A_(Kambin)等4个指标上有较大提升(P<0.05)。算法规划21例的平均时间为7.97±3.73 s,而医师传统规划普遍需耗时10 min以上。结论本研究提出的多约束最优穿刺路径规划算法为L5/S1节段的微创椎间盘射频消融术提供了一种一站式的解决方案。经过严谨的临床评价和实验验证,该算法显示出独特的优势和广阔的临床应用潜力。

基于外部气相沉积的S+C+L波段低色散斜率大有效面积非零色散位移光纤的设计与制备

针对现有光纤无法满足宽带光密集波分复用系统传输和S+C+L波段粗波分复用的要求,设计了一种具有中心凹陷的三角形芯+环形的折射率剖面,利用外部气相沉积工艺制备了一种非零色散位移光纤,并通过调整第一芯层的相对折射率和第二芯层与第一芯层的半径比,探究了其对光纤衰减、色散斜率和有效面积等参数的影响。研究发现,当第一芯层的相对折射率逐渐增大且第二芯层与第一芯层半径比逐渐减小时,零色散波长和有效面积逐渐减小。当第一芯层的相对折射率在0.52%~0.53%,芯层半径比在2.6~2.7时,光纤的有效面积接近70μm^(2),零色散波长在1420 nm附近,在1550 nm波段的色散系数大于8 ps·nm^(-1)·km^(-1),色散斜率为0.059 ps·nm^(-2)·km^(-1),可以较好地抑制传输过程中光非线性效应,满足长途干线网与城域网的使用要求。

Unveiling DNA methylation in Alzheimer’s disease:a review of array-based human brain studies

The intricacies of Alzheimer’s disease pathogenesis are being increasingly illuminated by the exploration of epigenetic mechanisms,particularly DNA methylation.This review comprehensively surveys recent human-centered studies that investigate whole genome DNA methylation in Alzheimer’s disease neuropathology.The examination of various brain regions reveals distinctive DNA methylation patterns that associate with the Braak stage and Alzheimer’s disease progression.The entorhinal cortex emerges as a focal point due to its early histological alterations and subsequent impact on downstream regions like the hippocampus.Notably,ANK1 hypermethylation,a protein implicated in neurofibrillary tangle formation,was recurrently identified in the entorhinal cortex.Further,the middle temporal gyrus and prefrontal cortex were shown to exhibit significant hypermethylation of genes like HOXA3,RHBDF2,and MCF2L,potentially influencing neuroinflammatory processes.The complex role of BIN1 in late-onset Alzheimer’s disease is underscored by its association with altered methylation patterns.Despite the disparities across studies,these findings highlight the intricate interplay between epigenetic modifications and Alzheimer’s disease pathology.Future research efforts should address methodological variations,incorporate diverse cohorts,and consider environmental factors to unravel the nuanced epigenetic landscape underlying Alzheimer’s disease progression.

基于BiLSTM-Attention的F_(10.7)指数预测模型与中国自主数据集的应用

F_(10.7)指数是太阳活动的重要指标,准确预测F_(10.7)指数有助于预防和缓解太阳活动对无线电通信、导航和卫星通信等领域的影响.基于F_(10.7)射电流量的特性,在双向长短时记忆网络(Bidirectional Long Short-Term Memory Network,BiLSTM)基础上融入注意力机制(Attention),提出了一种基于BiLSTM-Attention的F_(10.7)预报模型.在加拿大DRAO数据集上其平均绝对误差(MAE)为5.38,平均绝对百分比误差(MAPE)控制在5%以内,相关系数(R)高达0.987,与其他RNN模型相比拥有优越的预测性能.针对中国廊坊L&S望远镜观测的F_(10.7)数据集,提出了一种转换平均校准(Conversion Average Calibration,CAC)方法进行数据预处理,处理后的数据与DRAO数据集具有较高的相关性.基于该数据集对比分析了RNN系列模型的预报效果,实验结果表明,BiLSTM-Attention和BiLSTM两种模型在预测F_(10.7)指数方面具有较好的优势,表现出较好的预测性能和稳定性.

基于理性扩展热力学的L-S热声弹性理论框架

本文基于连续介质力学和理性扩展热力学分析流程,将L-S(Lord and Shulman)热弹性理论与声弹性理论相结合,建立L-S热声弹性理论的基本框架,包括运动学、力学与热力学、本构方程与演化方程、基本场方程四部分。在运动学部分,区分了Lagrange描述和Euler描述,以及3种不同的状态和构形,同时针对热声弹性情况定义了两类从自然状态到初始状态的转变过程;在力学与热力学部分,给出了质量守恒定律、动量守恒定律、角动量守恒定律、能量守恒定律以及熵产不等式,从而引出经典不可逆热力学的局限性;在本构方程与演化方程部分,介绍了扩展不可逆热力学原理,并基于理性扩展热力学流程,推导了从自然状态到初始状态、从初始状态到最终状态的热声弹性本构方程与演化方程,将热流作为本构自变量并考虑了热流与应变和温度的相关性;在最后一部分给出了基本场方程的运动方程形式和适用于数值模拟的一阶速度-应力-热流-温度微分方程。

Prognostic significance and relationship of SMAD3 phosphoisoforms and VEGFR-1 in gastric cancer:A clinicopathological study

BACKGROUND The TGF-β/SMAD3 and VEGFR-1 signaling pathways play important roles in gastric cancer metastasis.SMAD3 phosphorylation is a crucial prognostic marker in gastric cancer.AIM To determine the prognostic value and relationship of SMAD3 phospho-isoforms and VEGFR-1 in gastric cancer.METHODS This was a single-center observational study which enrolled 98 gastric cancer patients and 82 adjacent normal gastric tissues from patients aged 32-84 years(median age 65)between July 2006 and April 2007.Patients were followed up until death or the study ended(median follow-up duration of 28.5 mo).The samples were used to generate tissue microarrays(TMAs)for immunohistochemical(IHC)staining.The expressions of TGF-β1,pSMAD3C(S423/425),pSMAD3L(S204),and VEGFR-1 in gastric cancer(GC)tumor tissue and normal tissue were measured by IHC staining using TMAs obtained from 98 GC patients.Prognosis and survival information of the patients was recorded by Outdo Biotech from May 2007 to July 2015.The relationship between TGF-β1,pSMAD3C(S423/425),pSMAD3L(S204),and VEGFR-1 protein expression levels was analyzed using Pearson's correlation coefficient.The relationship between protein expression levels and clinicopathological parameters was analyzed using the Chi-squared test.A survival curve was generated using the Kaplan-Meier survival analysis.RESULTS TGFβ-1 and VEGFR-1 expression was significantly upregulated in gastric cancer tissue compared to adjacent noncancerous tissue.The positive expression of phosphorylated isoforms of Smad3 varied depending on the phosphorylation site[pSMAD3C(S423/425):51.0%and pSMAD3L(S204):31.6%].High expression of pSMAD-3L(S204)was significantly correlated with larger tumors(P=0.038)and later N stages(P=0.035).Additionally,high expression of VEGFR-1 was closely correlated with tumor size(P=0.015)and pathological grading(P=0.013).High expression of both pSMAD3L(S204)and VEGFR-1 was associated with unfavorable outcomes in terms of overall survival(OS).Multivariate analysis indicated that high expression of pSMAD3L(S204)and VEGFR-1 were independent risk factors for prognosis in GC patients.VEGFR-1 protein expression was correlated with TGF-β1(r=0.220,P=0.029),pSMAD3C(S423/425)(r=0.302,P=0.002),and pSMAD3L(S204)(r=0.201,P=0.047),respectively.Simultaneous overexpression of pSMAD3L(S204)and VEGFR-1 was associated with poor OS in gastric cancer patients.CONCLUSION Co-upregulation of pSMAD3L(S204)and VEGFR-1 can serve as a predictive marker for poor gastric cancer prognosis,and pSMAD3L(204)may be involved in enhanced gastric cancer metastasis in a VEGFR-1-dependent manner.

由Sălăvgean-q微分算子定义的具有对称共轭点的单叶调和函数类

在单复变函数几何理论的研究中,构造函数类及研究它的几何性质是目前国内外重要的研究课题。本文首先定义了一个Sălăgean-q微分算子,利用该算子,我们构建了一类具有特殊性质的倒结构单叶调和函数,这类函数具有对称共轭点。我们进一步推导出了这类函数的系数条件,并得到了相应的Fekete-Szegö不等式,这一发现有效地拓展了现有的知识范畴。这一成果不仅丰富了单复变函数的理论内容,也为调和函数的研究提供了新的视角和方法。更重要的是,这一研究可能为未来在信号处理、图像处理等领域的实际应用提供新的数学模型和算法基础。

On the Range of Action of Adult Culex pipiens s.l.

Mosquitoes are an interesting topic due to their medical importance, as they play an active role in the transmission of many pathogens and parasites, acting as vectors for various pathologies that are deadly to humans, such as dengue, yellow fever, chikungunya, West Nile virus, encephalitis and malaria, among many others that are less common. In terms of morbidity and mortality caused by vector-borne diseases, mosquitoes are the most dangerous animals for humanity and, although they also play a role in the ecosystem as a food source for other organisms, their importance for public health cannot be overlooked. As highly efficient vectors, they put more than three billion people at risk, mainly in tropical and subtropical regions as well as in Europe, since heat waves and flooding are becoming more frequent and severe, and summers are getting longer and warmer, accelerating mosquito development, biting rates, and the incubation of the pathogens within their bodies. Female mosquitoes bite to acquire proteins for the development of their ovaries and eggs and, in the process, acquire pathogens and/or parasites from one vertebrate host and transmit them to another, usually after a short period of replication. Three of their four life stages are lived in still freshwater, so it is crucial to understand their range of action when they reach adulthood and leave the water, in order to plan and implement local prevention measures. A set of georeferenced abundance data collected in mainland Portugal over seven years was linked to cartographed water bodies in a geographic information system to estimate the distances at which Culex pipiens s.l. had a significant presence, with criteria based on the size of the catches. The result allows for an estimate of the fly range of those mosquitoes, which can be used to focus countermeasures.

Accurate Diagnosis of SARS-CoV-2 JN.1 by Sanger Sequencing of Receptor-Binding Domain Is Needed for Clinical Evaluation of Its Immune Evasion

Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies.

有限元分析对骨质疏松条件下L5/S1斜外侧椎间融合与两种后路固定的生物力学研究

目的评估在骨质疏松条件下,行L5/S1节段斜外侧椎间融合术(oblique lateral interbody fusion at L5/S1,OLIF51)及其联合双侧皮质骨轨迹螺钉(cortical bone trajectory screw,CBT)和双侧椎弓根螺钉(bilateral pedicle screw,BPS)的生物力学性能。方法招募1名健康青年男性作为志愿者,获得其腰骶椎三维CT数据,在有限元分析软件中完成L4~S1三维模型,采用前路钛板(titanium plate,TP)固定的OLIF51手术模型、OLIF51+CBT和OLIF51+BPS手术模型的构建,分别命名为A、B、C、D模型。通过赋值、设定条件、施加载荷,分析不同条件下的生物力学特性。结果顺利完成4种有限元模型的构建。4种模型在所有运动中的平均活动度(range of motion,ROM)变化趋势为A模型>B模型>C模型>D模型;其中,与A模型相比,B模型降幅为84.21%~94.42%,C模型降幅为88.12%~96.40%,D模型降幅为90.07%~96.49%(P均<0.05);与B模型相比,C模型降幅为7.41%~52.38%,D模型降幅为27.78%~58.33%(P均<0.05)。3种手术模型在所有运动中的融合器(Cage)平均最大应力变化趋势为B模型>C模型>D模型;其中,与B模型相比,C模型降幅为12.89%~57.62%,D模型降幅为36.43%~73.11%;D模型和C模型相比,除左侧弯外差异均有统计学意义(P均<0.05);D模型降幅为21.83%~37.67%。3种手术模型在所有运动中的内固定平均最大应力变化趋势为B模型>C模型>D模型;与B模型相比,C模型降幅为3.55%~65.47%,D模型降幅为18.58%~84.41%;CBT应力大于BPS应力(P<0.05)。结论在OLIF51手术中,补充后路内固定可以增强融合节段的稳定性并减轻TP上的应力。不建议对骨质疏松症患者单独进行OLIF51手术,使用BPS辅助固定可达到最佳生物力学特性。接受CBT辅助内固定的患者术后需要佩戴支具,并尽量避免融合部位的右侧弯曲运动。

双相不锈钢S31803与SUS316L焊接工艺研究及性能分析

对双相不锈钢S31803与不锈钢SUS316L焊接工艺的优化及焊接接头性能进行分析。对双相不锈钢S31803和不锈钢SUS316L的特性与焊接难点等进行分析,对双相不锈钢S31803与不锈钢SUS316L的异种钢焊接工艺、焊接接头组织和性能进行实验,通过实验验证和性能分析,得出关于双相不锈钢S31803与不锈钢SUS316L异种钢焊接工艺的结论和建议。

经皮椎间孔镜椎间盘切除术治单节段L5/S1椎间盘突出症临床疗效研究

探讨治疗单节段L5/S1椎间盘突出症的经皮椎间孔镜椎间盘切除术的临床疗效。方法 对2020年10月至2022年12月期间扬州大学附属医院收治的78例单节段L5/S1椎间盘突出患者的临床资料进行回顾性分析,其中56例患者给予对照组椎板间入路治疗,22例患者给予观察组椎间孔入路治疗,观察两组临床症状疼痛和腰部活动功能的变化以及影像学指标椎间盘高度指数和椎间盘退变Pfirrmann分级的变化。结果 术后第三天观察组和对照组均能显著性缓解患者疼痛,两者缓解患者疼痛程度比较没有显著性差异;术后1年观察组和对照组腰部活动功能与术前相比均有显著性改善,两者改善患者腰部活动功能无明显差异;观察组和对照组术后1年均有显著的椎间盘高度降低,两者椎间盘高度下降程度相近;观察组和对照组术后1年椎间盘退变程度与术前均有显著性增加,两者椎间盘退变程度相似。结论 在治疗单节段L5/S1椎间盘突出症方面经椎间孔入路相比于经椎间孔入路,两者在缓解患者疼痛状况以及恢复腰椎功能方面具有同等效果,但都不能阻止腰椎间盘进一步退变。

血清NSE,NF-L,s100β与急性脑梗死患者神经功能缺损程度的关系研究

目的探讨分析血清神经元特异性烯醇化醇(NSE),神经丝蛋白L(NF-L),s100β蛋白(s100β)水平与急性脑梗死患者神经功能缺损程度的相关性。方法选取2017年2月-2019年10月到商丘市第一人民医院治疗的急性脑梗死患者135例为研究组,选取同时期入医院进行健康体检者122例为对照组,检测并对比2组血清中NSE,NF-L,s100β水平;神经功能缺损程度采用神经功能缺损(NIH Stroke Scale,NIHSS)量表评定,对比研究组中不同神经功能缺损程度的患者血清中NSE,NF-L,s100β水平;采用Pearson相关性分析法探讨研究组血清NSE,NF-L,s100β水平与急性脑梗死患者NIHSS评分的相关性。结果研究组患者血清NSE,NF-L,s100β水平高于对照组,差异均有统计学意义(P<0.05);研究组中度缺损组和重度缺损组血清NSE,NF-L,s100β水平高于轻度缺损伤组,且重度损伤组血清NSE,NF-L,s100β水平高于中度损伤组,差异均有统计学意义(P<0.05);血清NSE,NF-L,s100β水平与NIHSS评分呈正相关(r=0.909、0.823、0.730,P=0.000、0.000、0.000)。结论急性脑梗死患者血清NSE,NF-L,s100β水平存在异常变化,且血清NSE,NF-L,s100β水平与NIHSS评分呈显著正相关。

Artificial substrates preference for proliferation and immigration in Aurelia aurita(s. l.) polyps

The increasing amounts of artificial marine substrates, in many parts of the world have been proposed as a potential driver of Aurelia spp. blooms, on account of providing extra habitats for the settlement and the proliferation of the benthic stage(polyps). Previous experiments have mainly focused on the substrate choices of Aurelia spp. planulae. However, substrate preferences for the proliferation and immigration of polyps have not been reported. We monitored the propagation and immigration of Aurelia aurita(s. l.) polyps on two natural and nine artificial substrates at constant temperature(20±0.5°C) and salinity(30±0.5) in beakers and a glass aquarium in the laboratory, respectively. The results showed that, among artificial substrates, the highest number for polyp proliferation and immigration was found on nets, rigid polyvinyl chloride plates(RPVC), and wood. The lowest density of polyps was present on iron plates. Among natural substrates, the asexual reproduction rate of polyps on Patinopecten yessoensis(Jay, 1857) shells was significantly higher than Azumapecten farreri(Jones & Preston, 1904). On the account of the distinction in the roughness, chemical properties and biofilms of these material surfaces, bare artificial or natural substrates discriminatively affect the proliferation and the immigration of Aurelia spp. polyps at laboratory. These observations suggest that, even in the natural environment, different materials and texture may influence the composition and the abundance of the fouling communities and the assemblages of polyps and, indirectly, have effects on the amounts of released medusae.

通信受限下T-S模糊网络控制系统L_(1)动态输出反馈控制

针对通信受限的非线性网络控制系统,为兼顾系统性能和节约利用网络资源,引入事件触发通信机制(ETCM),利用时延建模方法和并行分布补偿(PDC)技术,将连续控制系统建模为一个采样数据误差依赖的非线性网络化系统模型;构建保守性低的时滞依赖和模糊基依赖的Lyapunov-Krasovskii泛函,给出增广系统稳定性和鲁棒性结果,得到鲁棒控制器存在的充分条件,提出一种基于线性矩阵不等式(LMIs)的事件触发参数,以及全局模糊L 1动态输出反馈控制器参数的协同设计方法。采用永磁同步电动机模型仿真验证,结果表明该设计方法可减少网络资源占用,达到闭环控制系统的性能要求。

1例EGFR L747S和L858R双突变肺腺癌患者的治疗

表皮生长因子受体(epidermal growth factor receptor,EGFR)突变中最常见的突变是外显子19缺失突变和外显子21 L858R突变,这两种突变都对EGFR酪氨酸激酶抑制剂(EGFR-tyrosine kinase inhibitors,EGFR-TKIs)有非常好的响应性。然而,EGFR-TKIs对罕见EGFR突变的疗效尚有争议。在治疗过程中,许多患者最终也会对EGFR-TKIs产生耐药性。此外,对于对奥希替尼产生耐药性的患者,特别是那些具有罕见或复杂突变的患者,仍然没有标准的治疗方案。本文介绍了1例具有EGFR L747S和L858R双突变的肺腺癌患者,该患者在出现奥希替尼耐药后接受帕博利珠单抗联合化疗治疗有效,且无疾病进展生存期为13个月。这是国内外首例在携带EGFR L747S和L858R双突变的肺腺癌患者对奥希替尼耐药之后使用帕博利珠单抗免疫治疗联合化疗的报道,本案例可为具有类似罕见突变患者的治疗提供参考。

不同跟踪方式下GPS L2C信号质量评估精度分析

卫星信号质量好坏会影响用户的使用性能,利用软件接收机的跟踪结果可以实现信号质量评估.GPS L2C信号的伪码是由CM码和CL码时分复用(time division multiplexing,TDM)组成,根据其信号特点可以使用不同的跟踪方式进行跟踪.针对不同跟踪方法对信号评估精度的影响,重点分析了信号一致性,信号的相关性能等指标.通过仿真信号分析和实测数据验证,结果表明:联合跟踪相比于单分量跟踪其评估精度更高,且各项指标的评估结果都优于单条支路的评估结果,使用联合跟踪会带来更小的测距误差.

Natural variations and geographical distributions of seed carotenoids and chlorophylls in 1167 Chinese soybean accessions

Understanding the composition and contents of carotenoids in various soybean seed accessions is important for their nutritional assessment.This study investigated the variability in the concentrations of carotenoids and chlorophylls and revealed their associations with other nutritional quality traits in a genetically diverse set of Chinese soybean accessions comprised of cultivars and landraces.Genotype,planting year,accession type,seed cotyledon color,and ecoregion of origin significantly influenced the accumulation of carotenoids and chlorophylls.The mean total carotenoid content was in the range of 8.15–14.72μg g–1 across the ecoregions.The total carotenoid content was 1.2-fold higher in the landraces than in the cultivars.Soybeans with green cotyledons had higher contents of carotenoids and chlorophylls than those with yellow cotyledons.Remarkably,lutein was the most abundant carotenoid in all the germplasms,ranging from 1.35–37.44μg g–1.Carotenoids and chlorophylls showed significant correlations with other quality traits,which will help to set breeding strategies for enhancing soybean carotenoids without affecting the other components.Collectively,our results demonstrate that carotenoids are adequately accumulated in soybean seeds,however,they are strongly influenced by genetic factors,accession type,and germplasm origin.We identified novel germplasms with the highest total carotenoid contents across the various ecoregions of China that could serve as the genetic materials for soybean carotenoid breeding programs,and thereby as the raw materials for food sectors,pharmaceuticals,and the cosmetic industry.

温度对L360QS管线钢在H_(2)S/CO_(2)环境中腐蚀行为的影响

采用腐蚀失重实验和电化学实验探究40~60℃条件下L360QS钢试样的腐蚀规律。实验结果表明:在CO_(2)-H_(2)S-Cl^(-)共存体系中,随着温度的升高,腐蚀速率逐渐增大,腐蚀程度加剧,并出现点蚀。当温度低于50℃时,腐蚀并不严重,当温度高于50℃时,腐蚀产物膜致密性和完整度降低,易溶解破裂,出现“大阴极小阳极”现象,促进发生局部腐蚀。同时得到管线钢以CO_(2)腐蚀为主,H2S腐蚀为辅,均匀腐蚀主要受CO_(2)控制,点蚀由高浓度的Cl-造成。

叶面喷施S-烯丙基-L-半胱氨酸对水稻砷转运影响机制

膳食稻米是我国人群摄入高致癌风险无机砷(iAs)的主要来源,开发降低稻米砷(As)含量生产措施对保护人体健康具有重要意义。本文以我国南方主栽水稻品种“中早35”为试验材料,采用盆栽试验研究了开花期叶面喷施S-烯丙基-L-半胱氨酸(SAC)对水稻籽粒和营养器官中总As含量的影响并揭示其潜在的分子机制。结果表明:当SAC喷施浓度达到0.2 mmol·L^(-1)时籽粒和根中总As含量分别显著降低42.3%和20.6%,但旗叶中总As含量显著增加了72.4%;荧光染色观察试验表明旗叶中H_(2)O_(2)含量显著降低,同时SOD和CAT酶活性分别显著升高61.8%和105.3%。喷施SAC后水稻顶端第一节中Lsi6转运子编码基因以及Lsi3转运子编码基因分别显著下调59.8%和36.3%,据此推测喷施SAC可能显著降低了水稻从通向旗叶膨大维管束流中卸载As^(Ⅲ)和向连接稻穗弥散维管束装载As^(Ⅲ)的能力,导致籽粒中总As含量显著降低而旗叶中总As含量显著升高。旗叶植物螯合素(PCs)合成酶OsPCS1和负责向细胞液泡中转运As^(Ⅲ)的OsABCC1转运子编码基因分别显著上调57.6%和61.0%,表明喷施SAC增加了旗叶合成PCs并向液泡中区隔As^(Ⅲ)的能力从而降低了叶片的As^(Ⅲ)胁迫。水稻根部Lsi1、Lsi2、Lsi3转运子编码基因分别显著下调了27.2%、23.8%、29.5%,表明水稻根部对As^(Ⅲ)的吸收、转运能力降低,同时可能也预示着As^(Ⅲ)向木质部导管中装载As^(Ⅲ)的能力降低。综上,喷施SAC通过调控As^(Ⅲ)转运子编码基因表达降低了水稻籽粒和根中总As含量,同时缓解了As胁迫。