Genetic polymorphism of UL144 open reading frame of human cytomegalovirus DNA detected in colon samples from infants with Hirschsprung's disease

AIM:To explore the genetic diversities of UL144 open reading frame (ORF) of cytomegalovirus DNA detected in colon tissue from infants with Hirschsprung's disease (HD) by sequencing UL144 DNA in 23 aganglionic colon tissue and 4 urine samples from 25 HD infants. METHODS:Nest PCR was performed for amplification of the UL144 gene. The UL144 gene was analyzed with softwares,such as DNAclub,BioEdit,PROSITE database,and DNAstar. RESULTS:The strains from HD patients were distributed among three genotypes of UL144:group 1A (64%),group 2 (24%),and group 3 (12%). The UL144 genotypes between strains from HD and control group were compared by chi square test (χ2 = 1.870,P = 0.393). Strains from the colon were sporadically distributed in UL144 genotypes. CONCLUSION:There are genetic diversities of UL144 ORF in colon tissue of infants with HD. However,cytomegalovirus UL144 genotypes are not associated with clinical manifestations of HD.

Perithyroidal hemorrhage caused by hydrodissection during radiofrequency ablation for benign thyroid nodules:Two case reports

BACKGROUND Hydrodissection is a widely used technique during radiofrequency ablation(RFA)for benign thyroid nodules.Although it could effectively avoid thermal injury to the surrounding critical structures and achieve complete treatment,routine operation of the remaining needle could cause perithyroidal hemorrhage.In this report,we present 2 cases of perithyroidal hemorrhage during RFA caused by a hydrodissection needle,which have not been reported before.CASE SUMMARY A 21-year-old female and a 45-year-old male were admitted for RFA for benign thyroid nodules.Considering that their nodules were adjacent to the recurrent laryngeal nerve,the needle used for hydrodissection was placed and remained between the dorsal capsule of the lateral lobe and the recurrent laryngeal nerve.During the procedure,active bleeding near the needle appeared on ultrasonography(US).Although moderate pressure was quickly applied to the neck for several minutes,contrast-enhanced US(CEUS)still showed an active hemorrhage.A radiofrequency electrode was placed at the bleeding point under the guidance of CEUS to stop the bleeding,and the procedure was finally confirmed to be successful by CEUS,without other complications.CONCLUSION Hydrodissection during RFA of benign thyroid nodules was associated with a risk of perithyroidal hemorrhage.The timely recognition of this acute hemorrhage could help in the timely control of the bleeding,and CEUS-guided ablation of the bleeding point could be useful.

Identification and characterization of a novel group of natural antisense transcripts from RNA1.2 gene locus of human cytomegalovirus

Background:Natural anti-sense transcripts(NATs),which are transcribed from the complementary DNA strand of annotated genes,exert regulatory function of gene expression.Increasing studies recognized anti-sense transcription widespread throughout human cytomegalovirus(HCMV)genome,whereas the anti-sense transcription of RNA1.2 gene locus has never been investigated.In this study,the transcription of the RNA1.2 anti-sense strand was investigated in clinically isolated HCMV strain.Methods:Strand-specific high-through RNA-sequencing(RNA-seq)was performed to find possible anti-sense transcripts(ASTs).For analyzing and visualization of RNA-seq data sets,Integrative Genomics Viewer software was applied.To confirm these possibilities,Northern blotting and rapid amplification of cDNA ends(RACE)were used.Results:Transcription of the opposite strand of RNA1.2 gene locus was detected by RNA-sequencing using RNAs extracted from human embryonic lung fibroblasts infected with HCMV clinical isolate HAN.At least three HCMV NATs,named RNA1.2 AST 1,RNA1.2 AST2,and RNA 1.2 AST3,were characterized by Northern blotting and RACE analyses.These RNA1.2 ASTs orientated from the complementary strand of RNA1.2 locus during the late phase of HCMV infection.The 5'-and 3'-termini of these transcripts were located within the opposite sequence of the predicted RNA1.2 gene.Conclusion:A cluster of novel NATs was transcribed from the opposite sequence of the HCMV RNA 1.2 gene region.

Maximum Likelihood Estimation via Duality for Cell Probabilities Subject to Convex and Log-convex Constraints

This article proposes a method for fitting models subject to a convex and log-convex constraint on the probability vector of a product multinomial （binomial） distribution. We present an iterative algorithm for finding the restricted maximum likelihood estimates （MLEs） of the probability vector and show that the algorithm converges to the true solution. Some examples are discussed to illustrate the method.

Formation of six-coordinated silicon in calcium phosphosilicate xerogels assisted by polyols at low temperature and pressure

Silicon is usually found to be four-coordinated when neighbored with oxygen. Six-coordinated silicon is only seen in samples at very specific composition or made at high temperature/pressure. In this study, we managed to synthesize calcium phosphosilicate xerogels containing six-coordinated silicon with the help of polyols by sol-gel method, without the need of treatment at high temperature or high pressure. Both phosphorus precursors and polyols were found to be essential for the formation of six-coordinated silicon species; in the absence of either species, only normal four-coordinated silicon was observed under otherwise identical conditions. Samples containing six-coordinated silicon sites were found to release silicon species faster than those without six-coordinated silicon sites upon dissolved in water, suggesting that six-coordinated silicon species have higher reactivity toward hydrolysis.

乙烯反应中的铁配合物催化剂:从概念到产业化

聚烯烃的核心是催化剂,地球上丰度最高的过渡元素铁的配合物在催化乙烯反应中展示了优异性能,本文综述了用于乙烯低聚与聚合的铁配合物催化剂的最新进展.通过调控所用配体的电子效应和空间位阻可以实现乙烯催化性能与所得聚合物微观结构的控制;铁催化剂具有独特的优势,不仅实现α-烯烃制备,而且可以制备高度线性聚乙烯包括制备窄分布的聚乙烯蜡.铁催化剂未来将在高附加值聚乙烯有巨大应用潜力.

Investigating the Effects of Para-methoxy Substitution in Sterically Enhanced Unsymmetrical Bis(arylimino)pyridine-cobalt Ethylene Polymerization Catalysts

A group of five bis(arylimino)pyridine-cobalt(Ⅱ)chloride complexes,[2-{(2,6-(Ph_(2)CH)_(2)-4-MeOC_(6)H_(2))N=CMe}-6-(ArN=CMe)C_5 H_(3)N]CoCl_(2)(Ar=2,6-Me_(2)C_(6)H_(3)Co1,2,6-Et_(2)C_(6)H_(3)Co2,2,6-iPr_(2)C_(6)H_(3)Co3,2,4,6-Me_(3)C_(6)H_(2)Co4,2,6-Et_(2)-4-MeC_(6)H_(2)Co5),each containing one N-4-methoxy-2,6-dibenzhydrylphenyl group and one smaller sterically/electronically variable N-aryl group,have been synthesized in good yield(>71%)from the corresponding neutral terdentate nitrogen-donor precursor,L1-L5.All complexes have been characterized by^(1)H-NMR and FTIR spectroscopy with the former highlighting the paramagnetic nature of these cobaltous species and the unsymmetrical nature of the chelating ligand.The molecular structures of Co3 and Co4 emphasize the steric differences of the two inequivalent N-aryl groups and the distorted square pyramidal geometry about the metal centers.In the presence of MAO or MMAO,Co1-Co5 collectively displayed high activities for ethylene polymerization producing high molecular weight polyethylenes that,in general,exhibited narrow dispersities(M_w/M_n values:2.12-4.07).Notably,the least sterically hindered Co1 when activated with MAO was the most productive(6.92×10^(6)g_(PE)·mol^(-1)_((Co))·h^(-1))at an operating temperature of60℃.Conversely,the most sterically hindered Co3/MMAO produced the highest molecular weight polyethylene(M_w=6.29×10^(5)g·mol^(-1)).All the polymers displayed high linearity as demonstrated by their melting temperatures(>130℃)and their~1 H-and^(13)C-NMR spectra.By comparison of Co1 with its para-methyl,-chloro and-nitro counterparts,the presence of the para-methoxy substituent showed the most noticeable effect of enhancing the thermal stability of the catalyst.

Dinuclear Nickel(Ⅱ) Chlorides Bearing N,N′-bis(5,6,7-trihydroquinolin-8-ylidene)-[1,1′-biphenyl]-4,4′-diamines: Synthesis and Ethylene Polymerization

5,6,7-Trihydroquinolin-8-one was condensed with the corresponding benzidine to give N,N′-bis（5,6,7-trihydroquinolin-8-ylidene）-[1,1′-biphenyl]-4,4′-diamine derivatives（L1–L3）. The ligands were reacted with two equivalents of Ni Cl2·6H2O in a mixture of Et OH and CH2Cl2 to afford the corresponding dinickel（II） chloride complexes（Ni1-Ni3）. The organic compounds were completely characterized, whilst the bi-metallic complexes were characterized by FTIR spectra and elemental analysis. These nickel complexes exhibited high activities towards ethylene polymerization in the presence of either MAO or Me2AlCl, maintaining a high activity over a prolonged period. The obtained polyethylenes were confirmed as having low molecular weights by GPC analysis.