Double helix point spread function with variable spacing for precise 3D particle localization.

To extend the axial depth of nanoscale 3D-localization microscopy, we propose here a splicing-type vortex singularities (SVS) phase mask, which has been meticulously optimized with a Fresnel approximation imaging inverse operation. The optimized SVS DH-PSF has proven to have high transfer function efficiency with adjustable performance in its axial range. The axial position of the particle was computed by using both the main lobes' spacing and the rotation angle, an improvement of the localization precision of the particle. Concretely, the proposed optimized SVS DH-PSF, with a smaller spatial extent, can effectively reduce the overlap of nanoparticle images and realize the 3D localization of multiple nanoparticles with small spacing, with respect to PSFs for large axial 3D localization. Finally, we successfully conducted extensive experiments on 3D localization for tracking dense nanoparticles at 8µm depth with a numerical aperture of 1.4, demonstrating its great potential.

Maize Dek407 Encodes the Nitrate Transporter 1.5 and Is Required for Kernel Development.

The kernel serves as the storage organ and harvestable component of maize, and it plays a crucial role in determining crop yield and quality. Understanding the molecular and genetic mechanisms of kernel development is of considerable importance for maize production. In this study, we obtained a mutant, which we designated defective kernel 407 (dek407), through ethyl methanesulfonate mutagenesis. The dek407 mutant exhibited reduced kernel size and kernel weight, as well as delayed grain filling compared with those of the wild type. Positional cloning and an allelism test revealed that Dek407 encodes a nitrate transporter 1/peptide transporter family (NPF) protein and is the allele of miniature 2 (mn2) that was responsible for a poorly filled defective kernel phenotype. A transcriptome analysis of the developing kernels showed that the mutation of Dek407 altered the expression of phytohormone-related genes, especially those genes associated with indole-3-acetic acid synthesis and signaling. Phytohormone measurements and analysis indicated that the endogenous indole-3-acetic acid content was significantly reduced by 66% in the dek407 kernels, which may be the primary cause of the defective phenotype. We further demonstrated that natural variation in Dek407 is associated with kernel weight and kernel size. Therefore, Dek407 is a potential target gene for improvement of maize yield.

The impact of COVID-19 on short-term prognosis of ST-segment elevation myocardial infarction patients receiving primary percutaneous coronary intervention in Wuhan China.

ST-segment elevation myocardial infarction (STEMI) is a common cardiovascular emergency for which timely reperfusion therapies are needed to minimize myocardial necrosis. The aim of this study was to investigate the impact of the COVID-19 pandemic and reorganization of chest pain centers (CPC) on the practice of primary percutaneous coronary intervention (PPCI) and prognosis of STEMI patients. This single-center retrospective survey included all patients with STEMI admitted to our CPC from January 22, 2020 to April 30, 2020 (during COVID-19 pandemic in Wuhan), compared with those admitted during the analogous period in 2019, in respect of important time points of PPCI and clinical outcomes of STEMI patients. In the present article, we observed a descending trend in STEMI hospitalization and a longer time from symptom onset to first medical contact during the COVID-19 pandemic as compared to the control period (4.35 h versus 2.58 h). With a median delay of 17 minutes in the door to balloon time (D2B), the proportion of in-hospital cardiogenic shock was significantly higher in the COVID-19 era group (47.6% versus 19.5%), and major adverse cardiac events (MACE) tend to increase in the 6-month follow-up period (14.3% versus 2.4%). Although the reorganization of CPC may prolong the D2B time, immediate revascularization of the infarct-related artery could be offered to most patients within 90 minutes upon arrival. PPCI remained the preferred treatment for patients with STEMI during COVID-19 pandemic in the context of timely implementation and appropriate protective measures.

Clinical characteristics of 116 hospitalized patients with COVID-19 in Wuhan, China: a single-centered, retrospective, observational study.

BACKGROUND: A cluster of acute respiratory illness, now known as Corona Virus Disease 2019 (COVID-19) caused by 2019 novel coronavirus (SARS-CoV-2), has become a global pandemic. Aged population with cardiovascular diseases are more likely be to infected with SARS-CoV-2 and result in more severe outcomes and elevated case-fatality rate. Meanwhile, cardiovascular diseases have a high prevalence in the middle-aged and elderly population. However, despite of several researches in COVID-19, cardiovascular implications related to it still remains largely unclear. Therefore, a specific analysis in regard to cardiovascular implications of COVID-19 patients is in great need. METHODS: In this single-centered, retrospective, observational study, 116 patients with laboratory-confirmed COVID-19 were enrolled, who admitted to the General Hospital of Central Theater Command (Wuhan, China) from January 20 to March 8, 2020. The demographic data, underlying comorbidities, clinical symptoms and signs, laboratory findings, chest computed tomography, treatment measures, and outcome data were collected from electronic medical records. Data were compared between non-severe and severe cases. RESULTS: Of 116 hospitalized patients with COVID-19, the median age was 58.5 years (IQR, 47.0-69.0), and 36 (31.0%) were female. Hypertension (45 [38.8%]), diabetes (19 [16.4%]), and coronary heart disease (17 [14.7%]) were the most common coexisting conditions. Common symptoms included fever [99 (85.3%)], dry cough (61 [52.6%]), fatigue (60 [51.7%]), dyspnea (52 [44.8%]), anorexia (50 [43.1%]), and chest discomfort (50 [43.1%]). Local and/or bilateral patchy shadowing were the typical radiological findings on chest computed tomography. Lymphopenia (lymphocyte count, 1.0 × 109/L [IQR, 0.7-1.3]) was observed in 66 patients (56.9%), and elevated lactate dehydrogenase (245.5 U/L [IQR, 194.3-319.8]) in 69 patients (59.5%). Hypokalemia occurred in 24 (20.7%) patients. Compared with non-severe cases, severe cases were older (64.0 years [IQR, 53.0-76.0] vs 56.0 years [IQR, 37.0-64.0]), more likely to have comorbidities (35 [63.6%] vs 24 [39.3%]), and more likely to develop acute cardiac injury (19 [34.5%] vs 4 [6.6%]), acute heart failure (18 [32.7%] vs 3 [4.9%]), and ARDS (20 [36.4%] vs 0 [0%]). During hospitalization, the prevalence of new onset hypertension was significantly higher in severe patients (55.2% vs 19.0%) than in non-severe ones. CONCLUSIONS: In this single-centered, retrospective, observational study, we found that the infection of SARS-CoV-2 was more likely to occur in middle and aged population with cardiovascular comorbidities. Cardiovascular complications, including new onset hypertension and heart injury were common in severe patients with COVID-19. More detailed researches in cardiovascular involvement in COVID-19 are urgently needed to further understand the disease.

[Rapid determination of 19 elements in human urine by inductively coupled plasma-mass spectrometry with dynamic reaction cell].

OBJECTIVE: A simple method is proposed for determination of Be, Rb, Sr, Cd, Pb, Cs, Tl, V, Cr, Mn, Ni, Co, Cu,Zn, Sn, Sb, Te, As and Se in urine by using inductively coupled plasma mass spectrometry with dynamic reaction cell. METHODS: Prior to analysis, samples were diluted (1: 20) in a solution of nitric acid (3%, V/V). The DRC mode was applied to determine the content of V51, Cr52, Mn55, Ni58, Co59, Cu63, Zn64 Sn120, Sb121, Te130, As75 and Se80. For the other elements, the instrument was operated in standard mode. RESULTS: The method detection limits were 2.7ng/L for Be9, 2.0ng/L for V51, 2.7ng/L for Cr52, 1.5ng/L for Mn55, 3.9ng/L for Ni58, 0.8ng/L for Co59, 5.8ng/L for Cu63, 35.3ng/L for Zn64, 32.4ng/L for As75, 21.1ng/L for Se80,1.4ng/L for Rb85, 4.2ng/ L for Sr88, 1.1 ng/L for Cd 9.1 ng/L for Sn120, 1.1ng/L for Sb121, 8.6ng/L for Te130, 0.1 ng/L for Cs133, 0.2ng/L for Tl205 and 1.0 ng/L for Pb208. The precisions of the method were in the range of 0.3% - 2.6%. CONCLUSION: The proposed method was rapid, accurate and can be used for measurement with simple pre-treatment, less sample and lower cost. The method was also suitable for massive samples in screening and monitoring.

Molecular mechanism underlying the hypolipidemic effect of Shanmei Capsule based on network pharmacology and molecular docking.

BACKGROUND: Shanmei Capsule is a famous preparation in China. However, the related mechanism of Shanmei Capsule against hyperlipidemia has yet to be revealed. OBJECTIVE: To elucidate underlying mechanism of Shanmei Capsule against hyperlipidemia through network pharmacology approach and molecular docking. METHODS: Active ingredients, targets of Shanmei Capsule as well as targets for hyperlipidemia were screened based on database. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed via Database for Annotation, Visualization, and Integrated Discovery (DAVID) 6.8 database. Ingredient-target-disease-pathway network was visualized utilizing Cytoscape software and molecular docking was performed by Autodock Vina. RESULTS: Seventeen active ingredients in Shanmei Capsule were screened out with a closely connection with 34 hyperlipidemia-related targets. GO analysis revealed 40 biological processes, 5 cellular components and 29 molecular functions. A total of 15 signal pathways were enriched by KEGG pathway enrichment analysis. The docking results indicated that the binding activities of key ingredients for PPAR-α are equivalent to that of the positive drug lifibrate. CONCLUSIONS: The possible molecular mechanism mainly involved PPAR signaling pathway, Bile secretion and TNF signaling pathway via acting on MAPK8, PPARγ, MMP9, PPARα, FABP4 and NOS2 targets.