Chromosome-Level Genome Assembly of a Fragrant Japonica Rice Cultivar ‘Changxianggeng 1813’ Provides Insights into Genomic Variations between Fragrant and Non-Fragrant Japonica Rice

East Asia has an abundant resource of fragrant japonica rice that is gaining increasing interest among both consumers and producers. However, genomic resources and in particular complete genome sequences currently available for the breeding of fragrant japonica rice are still scarce. Here, integrating Nanopore long-read sequencing, Illumina short-read sequencing, and Hi-C methods, we presented a high-quality chromosome-level genome assembly (~378.78 Mb) for a new fragrant japonica cultivar ‘Changxianggeng 1813’, with 31,671 predicated protein-coding genes. Based on the annotated genome sequence, we demonstrated that it was the badh2-E2 type of deletion (a 7-bp deletion in the second exon) that caused fragrance in ‘Changxianggeng 1813’. Comparative genomic analyses revealed that multiple gene families involved in the abiotic stress response were expanded in the ‘Changxianggeng 1813’ genome, which further supported the previous finding that no generalized loss of abiotic stress tolerance associated with the fragrance phenotype. Although the ‘Changxianggeng 1813’ genome showed high genomic synteny with the genome of the non-fragrant japonica rice cultivar Nipponbare, a total of 289,970 single nucleotide polymorphisms (SNPs), 96,093 small insertion-deletion polymorphisms (InDels), and 8690 large structure variants (SVs, >1000 bp) were identified between them. Together, these genomic resources will be valuable for elucidating the mechanisms underlying economically important traits and have wide-ranging implications for genomics-assisted breeding in fragrant japonica rice.     

Precision Killing of Sinoporphyrin Sodium-Mediated Photodynamic Therapy against Malignant Tumor Cells

Photodynamic therapy (PDT) has significant advantages in the treatment of malignant tumors, such as high efficiency, minimal invasion and less side effects, and it can preserve the integrity and quality of the organs. The power density, irradiation time and photosensitizer (PS) concentration are three main parameters that play important roles in killing tumor cells. However, until now, the underlying relationships among them for PDT outcomes have been unclear. In this study, human malignant glioblastoma U-118MG and melanoma A375 cells were selected, and the product of the power density, irradiation time and PS concentration was defined as the total photodynamic parameter (TPP), in order to investigate the mechanisms of PS sinoporphyrin sodium (DVDMS)-mediated PDT (DVDMS-PDT). The results showed that the survival rates of the U-118MG and A375 cells were negatively correlated with the TPP value in the curve, and the correlation exactly filed an e-exponential function. Moreover, according to the formula, we realized controllable killing effects of the tumor cells by randomly adjusting the three parameters, and we finally verified the accuracy and repeatability of the formula. In conclusion, the establishment and implementation of a newly functional relationship among the PDT parameters are essential for predicting PDT outcomes and providing personalized precise treatment, and they are contributive to the development of PDT dosimetry.     

Property and Stability of Astaxanthin Emulsion Based on Pickering Emulsion Templating with Zein and Sodium Alginate as Stabilizer

Astaxanthin loaded Pickering emulsion with zein/sodium alginate (SA) as a stabilizer (named as APEs) was developed, and its structure and stability were characterized. The encapsulation efficiency of astaxanthin (Asta) in APEs was up to 86.7 ± 3.8%, with a mean particle size of 4.763 μm. Freeze-dried APEs showed particles stacked together under scanning electronic microscope; whereas dispersed spherical nanoparticles were observed in APEs dilution under transmission electron microscope images. Confocal laser scanning microscope images indicated that zein particles loaded with Asta were aggregated with SA coating. X-ray diffraction patterns and Fourier transform infrared spectra results showed that intermolecular hydrogen bonding, electrostatic attraction and hydrophobic effect were involved in APEs formation. APEs demonstrated non-Newtonian shear-thinning behavior and fit well to the Cross model. Compared to bare Asta extract, APEs maintained high Asta retention and antioxidant activity when heated from 50 to 10 °C. APEs showed different stability at pH (3.0–11.0) and Na⁺, K⁺, Ca²⁺, Cu²⁺ and Fe²⁺ conditions by visual, zeta potential and polydispersity index measurements. Additionally, the first order kinetics fit well to describe APEs degradation at pH 3.0 to 9.0, Na⁺, and K⁺ conditions. Our results suggest the potential application of Asta-loaded Pickering emulsion in food systems as a fortified additive.     

综掘工作面压风分流控除尘技术研究与应用

为解决快速掘锚工作面的粉尘污染问题,以寸草塔煤矿22120工作面运输巷快速掘锚工作面为研究对象,通过FLUNET软件建立数值模拟模型,研究并优化控风、抽风风量的匹配关系,并结合现场实际应用进行验证,得到合适的掘锚工作面配套方式及最优工艺参数。研究结果表明：将除尘器安设于掘锚机顶部,并采用“附壁风筒+挡尘帘”进行控风除尘的工艺配套方式,掘锚工作面的粉尘质量浓度得到显著降低;当除尘器抽出风量为405 m³/min(即抽压风量比为0.9)时,工作面降尘效果明显,呼吸性粉尘的降尘效率达到95%以上,极大改善了掘锚工作面的作业环境。

     

浅层地热能开发回灌井施工技术研究——以郑州市东、西部新城区为例

地下水回灌是浅层地热能开发利用中不可缺少的环节,回灌井是实施回灌的关键设施,其施工技术是影响回灌效果的重要因素。选取郑州市东部新城区、西部新城区浅层地热能开发的回灌井为研究对象,分析不同区域地质条件的差异,通过回灌井结构分析地下水的回灌机理,论述影响回灌效果的因素。结合试验井施工情况,论述泥浆正循环钻进、泵吸反循环钻进、冲击钻进等不同钻进工艺的适用条件和施工中存在的问题,以及钢筋砼管、钢管和U-PVC管等不同成井管材对回灌效果的影响,探索提高单位回灌量的针对性措施,为今后郑州市及周边地区浅层地热能开发回灌井的施工提供参考。     

金属光子晶体薄膜可见光和微波波段传输性能

一维金属光子晶体薄膜是由金属-介质多层结构组成的等效均匀的各向异性超构材料。相比单层金属膜层,该结构在色散调控方面具有更多的自由度。在该结构中由于表面等离子体激元(SPP)的存在,可实现倏逝波的定向传输。在本文中,等效介质理论、时域有限元差分法(FDTD)的计算结果和实验结果都表明,传输倏逝波的波长、频宽和强度可通过金属光子晶体结构调整实现主动设计。金属膜厚比例越小,传输波长的中心和截止波长越长,频带越宽。当金属膜层厚度小于SPP穿透深度时,可获得宽频段的倏逝波的传输。同时,对金属光子晶体在微波波段的传输性能也进行了研究,发现其在微波波段等效介电常数为负,具有良好的反射性能。该结构的屏蔽效能远大于厚度相近的ITO薄膜的电磁屏蔽效能。在厚度只有几百纳米时,该结构即可实现良好的电磁屏蔽效能。通过金属光子晶体薄膜可实现电磁屏蔽材料的薄膜化、轻质化和可视化。     

弹性波能量集中器散射效应的FRFT分析

由于弹性波传播动力学方程较复杂,若通过材料参数设计控制弹性波的传播路径,难以获得准确的设计结果。通常在对弹性波材料进行设计时,需要根据实际情况(如高频条件),对动力学方程进行简化或者近似才可以设计出基于弹性波的相应器件。由于这种设计方法的阻抗匹配和介质材料的无损要求难以满足,使得在设计弹性波传播器件过程中出现散射现象,而且往往散射的波形还是频变的信号,因此,在评价弹性波器件设计优劣时,散射现象的大小标志着设计效果的好坏,成为评价设计的手段和工具。但是,散射现象往往仅根据肉眼观察,难以准确地描述,无法给出定量的结果进行说明。为此,本文提出的分数阶Fourier变换(FRFT)对频变信号具有良好的聚焦特性,可利用频率变化的调频率,定量描述散射效应的大小,给出弹性波传播控制散射效应的一种定量的描述方法,降低散射程度认知的盲目性,为简化材料介质参数的设计提供依据。     

新型捕收剂KZ在氧化铅锌矿浮选中的应用

氧化铅锌矿的选矿是国内外选矿界公认的难题。经过大量的设计、复配研究,成功开发了氧化锌新型捕收剂,获得了锌精矿品位35.09%、回收率86.69%指标,达到了国内先进水平。