Molecular Identification of the G-Protein Genes and Their Expression Profiles in Response to Nitrogen Deprivation in Brassica napus

Heterotrimeric guanine nucleotide binding protein (G-protein) consisting of Gα, Gβ, and Gγ subunits is one of the key signal transducers in plants. Recent studies indicated that G-protein has been proposed as an important mediator of nitrogen responses in rice, wheat, and Arabidopsis. However, little is known about these G-proteins in Brassica napus (B. napus), except for three identified G-proteins, BnGA1, BnGB1, and BnGG2. Therefore, the aim of the present study is to characterize the members of the G-protein gene family in allotetraploid B. napus and to analyze their expression profiles in response to nitrogen deprivation. In total, 21 G-protein family members were identified in B. napus, encoding two Gα, six Gβ, and 13 Gγ. Sequence and phylogenetic analyses showed that although genome-wide triploid events increased the number of genes encoding Gα, Gβ, and Gγ subunits, the gene structure and protein properties of the genes encoding each G-protein subunit were extremely conserved. Collinearity analysis showed that most G-protein genes in B. napus had syntenic relationships with G-protein members of Arabidopsis, Brassica rape (B. rapa), and Brassica oleracea (B. oleracea). Expression profile analysis indicated that Gα and C-type Gγ genes (except BnGG10 and BnGG12 were highly expressed in flower and ovule) were barely expressed in most organs, whereas most Gβ and A-type Gγ genes tended to be highly expressed in most organs. G-protein genes also showed various expression patterns in response to nitrogen-deficient conditions. Under nitrogen deficiency, Gα and five C-type Gγ genes were upregulated initially in roots, while in leaves, Gα was downregulated initially and five C-type Gγ genes were highly expressed in different times. These results provide a complex genetic dissection of G-protein genes in B. napus, and insight into the biological functions of G-protein genes in response to nitrogen deficiency.     

Nutritional Calcium Supply Dependent Calcium Balance,Bone Calcification and Calcium Isotope Ratios in Rats

Serum calcium isotopes (δ^44/42Ca) have been suggested as a non-invasive and sensitive Ca balance marker. Quantitative δ^44/42Ca changes associated with Ca flux across body compartment barriers relative to the dietary Ca and the correlation of δ^44/42Ca_Serum with bone histology are unknown. We analyzed Ca and δ^44/42Ca by mass-spectrometry in rats after two weeks of standard-Ca-diet (0.5%) and after four subsequent weeks of standard- and of low-Ca-diet (0.25%). In animals on a low-Ca-diet net Ca gain was 61 ± 3% and femur Ca content 68 ± 41% of standard-Ca-diet, bone mineralized area per section area was 68 ± 15% compared to standard-Ca-diet. δ^44/42Ca was similar in the diets, and decreased in feces and urine and increased in serum in animals on low-Ca-diet. δ^44/42Ca_Bone was higher in animals on low-Ca-diet, lower in the diaphysis than the metaphysis and epiphysis, and unaffected by gender. Independent of diet, δ^44/42Ca_Bone was similar in the femora and ribs. At the time of sacrifice, δ^44/42Ca_Serum inversely correlated with intestinal Ca uptake and histological bone mineralization markers, but not with Ca content and bone mineral density by µCT. In conclusion, δ^44/42Ca_Bone was bone site specific, but mechanical stress and gender independent. Low-Ca-diet induced marked changes in feces, serum and urine δ^44/42Ca in growing rats. δ^44/42Ca_Serum inversely correlated with markers of bone mineralization.     

Antigens and Antibodies of the Antiphospholipid Syndrome as New Allies in the Pathogenesis of COVID-19 Coagulopathy

High prevalence of both criteria and extra-criteria antiphospholipid antibodies (aPL) has been reported in COVID-19 patients. However, the differences in aPL prevalence decreased when an age-matched control group was included. The association of aPL with thrombotic events in COVID-19 is very heterogeneous. This could be influenced by the fact that most of the studies carried out were conducted on small populations enriched with elderly patients in which aPL was measured only at a single point and they were performed with non-standardized assays. The few studies that confirmed aPL in a second measurement showed that aPL levels hardly changed, with the exception of the lupus anticoagulant that commonly reduced. COVID-19 coagulopathy is an aPL-independent phenomenon closely associated with the onset of the disease. Thrombosis occurs later in patients with aPL presence, which is likely an additional prothrombotic factor. B2-glycoprotein deficiency (mainly aPL antigen caused both by low production and consumption) is very common during the SARS-CoV2 infection and has been associated with a greater predisposition to COVID-19 complications. This could be a new prothrombotic mechanism that may be caused by the blockage of its physiological functions, the anticoagulant state being the most important.     

Sensitivity to zinc of Mediterranean woody species important for restoration

Heavy metals have increased in natural woodlands and shrublands over the last several decades as a consequence of anthropogenic activities. However, our knowledge of the effects of these elements on woody species is scarce. In this study, we examined the responses of six Mediterranean woody species to increasing levels of zinc in hydroponic culture and discussed the possible implications for the restoration of contaminated sites. The species used, Pinus pinea L., Pinus pinaster Ait., Pinus halepensis Mill., Tetraclinis articulata (Vahl) Mast., Rhamnus alaternus L. and Quercus suber L. represent a climatic gradient from dry sub-humid to semi-arid conditions. Zinc concentrations in shoots ranged from 53 μg g^− 1 in Q. suber to 382 μg g^− 1 in T. articulata and were well below the levels found in roots. Zinc inhibited root elongation and root biomass and changed the root length distribution per diameter class, but the magnitude of the effects was species-specific. Only P. halepensis and Q. suber showed toxicity symptoms in aboveground parts. Species more characteristic from xeric environments (T. articulata, R. alaternus and P. halepensis) were more sensitive to zinc than species from mesic environments (Q. suber, P. pinaster and P. pinea). According to the Zn responses and bioaccumulation, Q. suber P. pinea and P. halepensis are the best candidates for field trials to test the value of woody species to restore contaminated sites. None of the species tested seemed suitable for phytoremediation.     

四-(4-三甲铵苯基)卟啉测定食品中的超痕量锌

以水溶性α,β,γ,δ-四-(4-三甲铵苯基)卟啉[T-4-TAP)P]作显色剂,测定食品中的痕量锌。对实验条件及共存离子的干扰进行了探讨。室温下,在弱酸性介质中,经7-碘-8羟基卟啉-5-磺酸催化,反应生成1:1络合物。最大吸收波长为422nm摩尔吸收系数为4.0×10~5 1·mo1~(-1)·cm~(-1),桑德尔指数为0.16ng·cm~(2-1),变异系数为1.6—3.7%,回收率为90.8%。本方法适用于分析食品中的痕量锌。     

高可见光透射率的溴取代萘酞菁锌化合物的光限幅特性研究

应用倍频Nd:YAG脉冲激光,在波长为532nm,脉冲宽度分别为8ns和23ps的条件下,研究了四溴-2,3-萘酞菁锌()(tetrabromo-2,3-naphthalocyanineZinc())化合物的光限幅特性。实验结果表明,在可见光透射率达到93%的条件下,该化合物具有良好的光限幅特性     

嵌入式操作系统下SNMP协议的分析与实现

SNMP是目前Internet中网关和主机设备管理的最重要协议，嵌入式操作系统近年来发展很快，如何在嵌入式操作系统下简洁有效地实现网络管理功能需要考虑一系列问题。文中结合实际设计项目，对简单网络管理协议在VxWorks系统上的实现原理及实现过程进行了分析与介绍。     

Template Deformation‐Tailored ZnO Nanorod/Nanowire Arrays: Full Growth Control and Optimization of Field‐Emission

Here, a facile and effective route toward full control of vertical ZnO nanorod (NR)/nanowire (NW) arrays in centimeter‐scale areas and considerable improvement of field‐emission (FE) performance is reported. Controlled deformation of colloidal crystal monolayer templates is introduced by heating near glass‐transition temperature. The NR/NW density, uniformity, and tapering were all adjusted through selection of template size and deformation, and electrolyte composition. In line with the adjustments, the field‐emission performance of the arrays is significantly improved. A low turn‐on electric field of 1.8 V µm^?1, a field‐enhancement factor of up to 5 750, and an emitting current density of up to 2.5 mA cm^?2 were obtained. These improved parameters would benefit their potential application in cold‐cathode‐based electronics.     

Surface Wettability of Nanostructured Zinc Oxide Films

Zinc oxide (ZnO) nanograin and nanorod films were prepared by magnetron sputter deposition and an aqueous solution growth method. Their surface wettability was studied in relation to their surface morphologies. While the surfaces of both films were hydrophobic, the nanorod films exhibited higher surface hydrophobicity. A superhydrophobic surface was obtained on a ZnO nanorod film with a water contact angle of 151 deg. Results have shown that their surface wettability was influenced by the morphology of ZnO nanostructures, including the grain size, the length, and density of nanorods. Both types of ZnO films showed switchable wettability under ultraviolet irradiation and dark storage.