Axial resolution enhancement of light‐sheet microscopy by double scanning of Bessel beam and its complementary beam

The side lobes of Bessel beam will create significant out‐of‐focus background when scanned in light‐sheet fluorescence microscopy (LSFM), limiting the axial resolution of the imaging system. Here, we propose to overcome this issue by scanning the sample twice with zeroth‐order Bessel beam and another type of propagation‐invariant beam, complementary to the zeroth‐order Bessel beam, which greatly reduces the out‐of‐focus background created in the first scan. The axial resolution can be improved from 1.68 μm of the Bessel light‐sheet to 1.07 μm by subtraction of the two scanned images across a whole field‐of‐view of up to 300 μm × 200 μm × 200 μm. The optimization procedure to create the complementary beam is described in detail and it is experimentally generated with a spatial light modulator. The imaging performance is validated experimentally with fluorescent beads as well as eGFP‐labeled mouse brain neurons.      

Apple Fruit Diameter and Length Estimation by Using the Thermal and Sunshine Hours Approach and Its Application to the Digital Orchard Management Information System

In apple cultivation, simulation models may be used to monitor fruit size during the growth and development process to predict production levels and to optimize fruit quality. Here, Fuji apples cultivated in spindle-type systems were used as the model crop. Apple size was measured during the growing period at an interval of about 20 days after full bloom, with three weather stations being used to collect orchard temperature and solar radiation data at different sites. Furthermore, a 2-year dataset (2011 and 2012) of apple fruit size measurements were integrated according to the weather station deployment sites, in addition to the top two most important environment factors, thermal and sunshine hours, into the model. The apple fruit diameter and length were simulated using physiological development time (PDT), an indicator that combines important environment factors, such as temperature and photoperiod, as the driving variable. Compared to the model of calendar-based development time (CDT), an indicator counting the days that elapse after full bloom, we confirmed that the PDT model improved the estimation accuracy to within 0.2 cm for fruit diameter and 0.1 cm for fruit length in independent years using a similar data collection method in 2013. The PDT model was implemented to realize a web-based management information system for a digital orchard, and the digital system had been applied in Shandong Province, China since 2013. This system may be used to compute the dynamic curve of apple fruit size based on data obtained from a nearby weather station. This system may provide an important decision support for farmers using the website and short message service to optimize crop production and, hence, economic benefit.     

Synonymous Codon Usage Bias in Plant Mitochondrial Genes Is Associated with Intron Number and Mirrors Species Evolution

Synonymous codon usage bias (SCUB) is a common event that a non-uniform usage of codons often occurs in nearly all organisms. We previously found that SCUB is correlated with both intron number and exon position in the plant nuclear genome but not in the plastid genome; SCUB in both nuclear and plastid genome can mirror the evolutionary specialization. However, how about the rules in the mitochondrial genome has not been addressed. Here, we present an analysis of SCUB in the mitochondrial genome, based on 24 plant species ranging from algae to land plants. The frequencies of NNA and NNT (A- and T-ending codons) are higher than those of NNG and NNC, with the strongest preference in bryophytes and the weakest in land plants, suggesting an association between SCUB and plant evolution. The preference for NNA and NNT is more evident in genes harboring a greater number of introns in land plants, but the bias to NNA and NNT exhibits even among exons. The pattern of SCUB in the mitochondrial genome differs in some respects to that present in both the nuclear and plastid genomes.     

The PWWP domain of mammalian DNA methyltransferase Dnmt3b defines a new family of DNA-binding folds

The PWWP domain is a weakly conserved sequence motif found in > 60 eukaryotic proteins, including the mammalian DNA methyltransferases Dnmt3a and Dnmt3b. These proteins often contain other chromatin-association domains. A 135-residue PWWP domain from mouse Dnmt3b (amino acids 223--357) has been structurally characterized at 1.8 A resolution. The N-terminal half of this domain resembles a barrel-like five-stranded structure, whereas the C-terminal half contains a five-helix bundle. The two halves are packed against each other to form a single structural module that exhibits a prominent positive electrostatic potential. The PWWP domain alone binds DNA in vitro, probably through its basic surface. We also show that recombinant Dnmt3b2 protein (a splice variant of Dnmt3b) and two N-terminal deletion mutants (Delta218 and Delta369) have approximately equal methyl transfer activity on unmethylated and hemimethylated CpG-containing oligonucleotides. The Delta218 protein, which includes the PWWP domain, binds DNA more strongly than Delta369, which lacks the PWWP domain.     

New therapy with XLQ® to suppress chronic prostatitis through its anti-inflammatory and antioxidative activities

Chronic prostatitis is a common urological disease. The etiology of this disease and effective therapy for its treatment are yet to be elucidated. We investigated the functions of XLQ^® in chronic nonbacterial prostatitis using a complete Freund's adjuvant-induced rat model. Prostates and blood samples were collected for further evaluation after oral gavage with XLQ ^® or a vehicle for 4 weeks. The results showed that XLQ ^® significantly decreased the prostate index, ameliorated the histopathologic changes, and reduced CD3+ and CD45+ cell infiltration in the prostate stroma. Further study showed that XLQ ^® suppressed the expression of proinflammatory cytokines, such as interleukin (IL)-1β, IL-2, IL-6, IL-17A, monocyte chemoattractant protein-1, and tumor necrosis factor-α. XLQ ^® showed a strong antioxidant capacity by enhancing the activities of antioxidative enzymes (e.g., total superoxide dismutase, catalase, and glutathione peroxidase) and decreasing the level of lipid peroxidation products (malondialdehyde). Moreover, XLQ ^® can suppress the activation of nuclear factor-κB and P38-mitogen-activated protein kinase signaling pathways. In summary, XLQ ^® has affirmative effects on chronic prostatitis, which could be attributed to its anti-inflammatory and antioxidative capacities. On the basis of these results, XLQ ^® can be developed as an effective and safe therapy for chronic prostatitis.     

成年去胸腺大鼠和老年大鼠肝微粒体混合功能氧化酶及血浆性激素水平的变化

成年去胸腺(ATx)大鼠和老年大鼠肝微粒体混合功能氧化酶(MFO,包括细胞色素P450、氨基比林-N-脱甲基酶)的活力比成年对照大鼠的低,且降低幅度雄性明显大于雌性。雄性ATx大鼠和老年大鼠血浆睾酮(T)水平降低,雌二醇(E_2)水平增高,E_2/T比值明显增高;雌性ATx大鼠和老年大鼠血浆E_2和T水平均降低,E_2/T比值无明显变化。给雄性ATx大鼠皮下注射丙酸睾丸素可使其肝微粒体MFO活力恢复。提示胸腺对肝脏MFO的影响可能是通过性激素介导的。     

人白细胞介素18的基因克隆与表达

人白细胞介素１８（ＩＬ－１８）是新近发现的细胞因子之一．研究表明它参与Ｔ１辅助细胞介导的细胞免疫．利用ＲＴ－ＰＣＲ技术从人外周血细胞扩增得到了ＩＬ－１８的ｃＤＮＡ并测定其核酸序列．利用基因重组技术构建ＩＬ－１８的表达载体,并在大肠杆菌中进行了表达．这为以后进一步研究ＩＬ－１８的功能奠定了基础．