江西双季稻氮素监测诊断模型的建立与应用

建立基于光谱仪的江西双季稻氮素监测诊断模型,可指导氮肥精确施用,达到双季稻丰产、提质、增效的目的。本研究开展了不同早、晚稻品种与氮素水平的小区试验,采用GreenSeeker光谱仪和作物生长监测诊断仪(CGMD)于分蘖期和拔节期测定了早、晚稻冠层光谱植被指数和植株氮积累量,建立了双季稻植株氮积累量光谱监测模型,并采用独立的田间试验数据对模型进行检验。利用双季稻丰产栽培经验及建立的氮素光谱诊断模型,对双季稻分蘖肥和穗肥施氮量进行定量推荐。结果表明: 双季稻氮肥施用关键期(分蘖期和拔节期)基于两种光谱仪的光谱植被指数与植株氮积累量均呈显著正相关,分蘖期和拔节期的模型预测效果比生长前期模型好。基于GreenSeeker光谱仪的归一化差值植被指数(NDVI_(780,660))的指数方程可较好地预测植株氮积累量,模型决定系数(R²)为0.92～0.94,模型检验的均方根误差(RMSE)、相对均方根误差(RRMSE)和相关系数(r)分别为3.09～5.96 kg·hm^-2、5.8%～18.5%和0.92～0.98;基于CGMD光谱仪的差值植被指数(DVI_(810,720))的线性方程可较好地预测植株氮积累量,R²为0.90～0.93,模型检验的RMSE、RRMSE和r分别为3.71～6.33 kg·hm^-2、11.7%～14.3%和0.93～0.96。基于CGMD光谱仪的模型推荐的施氮量高于基于GreenSeeker光谱仪的模型推荐的施氮量;模型生成的精确施氮方案较传统农户方案减少施氮量5.5 kg·hm^-2,氮肥农学利用率提高0.8%,纯收益提高128元·hm^-2。用双季稻氮素光谱诊断方法指导施肥能在增产的同时,降低成本,增加纯收益,对科学指导双季稻生产具有重要意义。     

B para-Bombay phenotype in China caused by homozygous mutation for site 328 G > A of FUT1 gene: a case report

The aim of this paper is to accurately identify a case of B para-Bombay and to analyze the genetic mutation. ABO and Lewis blood groups were identified by standard serological methods, and trace antigens on RBCs were detected by adsorption-elution test, while blood group substances in the saliva were detected by agglutination inhibition test. The ABO gene exons 6-7, FUT1 gene exon 4 and FUT2 gene exon 2 were directly sequenced. Serological results showed that there were B antigens on RBCs without H antigens, anti-A and anti-HI antibodies in serum, and B and H blood group substances in the saliva. The Lewis phenotype was Le (a-b+). According to gene sequencing analysis, ABO, FUT1 and FUT2 genotypes were B101/O02, h^328G/Ah3^28G/A and Se^357C/TSe^357C/T, respectively. This rare phenotype can be mislabeled as "O" if any of the detailed investigations are not performed. Therefore, in order to ensure the safety of blood transfusion, genetic and serological tests are necessary for the correct identification of difficult blood groups.     

Dexamethasone does not ameliorate gliosis in a mouse model of neurodegenerative disease

Prolonged neuroinflammation is a driving force for neurodegenerative disease, and agents against inflammatory responses are regarded as potential treatment strategies. Here we aimed to evaluate the prevention effects on gliosis by dexamethasone (DEX), an anti-inflammation drug. We used DEX to treat the nicastrin conditional knockout (cKO) mouse, a neurodegenerative mouse model. DEX (10 mg/kg) was given to 2.5-month-old nicastrin cKO mice, which have not started to display neurodegeneration and gliosis, for 2 months. Immunohistochemistry (IHC) and Western blotting techniques were used to detect changes in neuroinflammatory responses. We found that activation of glial fibrillary acidic protein (GFAP) positive or ionized calcium binding adapter molecule1 (Iba1) positive cells was not inhibited in nicastrin cKO mice treated with DEX as compared to those treated with saline. These data suggest that DEX does not prevent or ameliorate gliosis in a neurodegenerative mouse model when given prior to neuronal or synaptic loss.     

The atlas of RNase H antisense oligonucleotide distribution and activity in the CNS of rodents and non-human primates following central administration

Antisense oligonucleotides (ASOs) have emerged as a new class of drugs to treat a wide range of diseases, including neurological indications. Spinraza, an ASO that modulates splicing of SMN2 RNA, has shown profound disease modifying effects in Spinal Muscular Atrophy (SMA) patients, energizing efforts to develop ASOs for other neurological diseases. While SMA specifically affects spinal motor neurons, other neurological diseases affect different central nervous system (CNS) regions, neuronal and non-neuronal cells. Therefore, it is important to characterize ASO distribution and activity in all major CNS structures and cell types to have a better understanding of which neurological diseases are amenable to ASO therapy. Here we present for the first time the atlas of ASO distribution and activity in the CNS of mice, rats, and non-human primates (NHP), species commonly used in preclinical therapeutic development. Following central administration of an ASO to rodents, we observe widespread distribution and target RNA reduction throughout the CNS in neurons, oligodendrocytes, astrocytes and microglia. This is also the case in NHP, despite a larger CNS volume and more complex neuroarchitecture. Our results demonstrate that ASO drugs are well suited for treating a wide range of neurological diseases for which no effective treatments are available.     

Metabolomic Profiling and Neuroprotective Effects of Purslane Seeds Extract Against Acrylamide Toxicity in Rat’s Brain

Neurochemical Research - Acrylamide (ACR) is an environmental pollutant with well-demonstrated neurotoxic and neurodegenerative effects in both humans and experimental animals. The present study...     

Mesenchymal stem cell‐conditioned medium attenuates the retinal pathology in amyloid‐β‐induced rat model of Alzheimer's disease: Underlying mechanisms

Amyloid‐beta (Aβ) oligomer is known to contribute to the pathophysiology of age‐related macular degeneration. Herein, we aimed to elucidate the in vivo and in vitro effects of Aβ_1‐42 application on retinal morphology in rats. Our in vivo studies revealed that intracerebroventricular administration of Aβ_1‐42 oligomer caused dysmorphological changes in both retinal ganglion cells and retinal pigment epithelium. In addition, in vitro studies revealed that ARPE‐19 cells following Aβ_1‐42 oligomer application had decreased viability along with apoptosis and decreased expression of the tight junction proteins, increased expression of both phosphor‐AKT and phosphor‐GSK3β and decreased expression of both SIRT1 and β‐catenin. Application of conditioned medium (CM) obtained from mesenchymal stem cells (MSC) protected against Aβ_1‐42 oligomer‐induced retinal pathology in both rats and ARPE‐19 cells. In order to explore the potential role of peptides secreted from the MSCs, we applied mass spectrometry to compare the peptidomics profiles of the MSC‐CM. Gene ontology enrichment analysis and String analysis were performed to explore the differentially expressed peptides by predicting the functions of their precursor proteins. Bioinformatics analysis showed that 3‐8 out of 155–163 proteins in the MSC‐CM maybe associated with SIRT1/pAKT/pGSK3β/β‐catenin, tight junction proteins, and apoptosis pathway. In particular, the secretomes information on the MSC‐CM may be helpful for the prevention and treatment of retinal pathology in age‐related macular degeneration.