Rongalite/iodine-mediated C(sp3)-H bond oximation and thiomethylation reaction of methyl ketones using copper nitrate as the [NO] reagent: synthesis of thiohydroximic acids.

In this work, a highly efficient rongalite/iodine-mediated oxime formation reaction for the preparation of thiohydroximic acids from methyl ketones by employing copper nitrate as the [NO] reagent has been developed. Notably, copper nitrate participated as both a catalyst and the mild oximation reagent in the transformation. This reaction is highly efficient and facile, with a broad substrate scope, especially for fused ring skeleton substrates, heterocyclic skeleton substrates, and acetyl-substituted natural products. Mechanistic studies revealed that copper nitrate might be converted into a NO2 radical or the NO2 radical dimeric forms as an ion-pair equivalent to participate in the transformation.

Copper-Catalyzed Multicomponent Coupling Reaction of Primary Aromatic Amines, Rongalite, and Alkynes: Access to N-Aryl Propargylamines.

In this work, a practical copper-catalyzed multicomponent coupling reaction of primary aromatic amines, rongalite, and alkynes for the direct synthesis of N-aryl propargylamines has been developed. This method could overcome the substrate limitation in A3 coupling reactions of primary aromatic amines, formaldehyde, and alkynes. Mechanistic studies revealed that rongalite acts as not only the active C1 unit but also the accelerator to activate the in situ-generated N-arylmethanimines for the coupling reaction with alkynes. This coupling reaction is highly efficient and features a broad substrate scope, as well as utility with scale-up synthesis and converting the corresponding product N-aryl propargylamines into useful heterocyclic skeletons.

Genomic characterization of three bacteriophages infecting donkey-derived Escherichia coli.

Bacteriophages are an important source of novel genetic diversity. Sequencing of phage genomes can reveal new proteins with potential uses in phage therapy and help unravel the diversity of biological mechanisms by which phages take over the machinery of the host during infection. To expand the available collection of phage genomes, we have isolated, sequenced, and assembled the genome sequences of three phages that infect three pathogenic Escherichia coli strains: vB_EcoM_DE15, vB_EcoM_DE16, and vB_EcoM_DE17. Morphological characterization and genomic analysis indicated that all three phages were strictly lytic and free from integrases, virulence factors, toxins, and antimicrobial resistance genes. All three phages contained tRNAs, and especially, vB_EcoM_DE17 contained 25 tRNAs. The genomic features of these phages indicate that natural phages are capable of lysing pathogenic E.coli and have great potential in the biocontrol of bacteria.

Characterization and complete genome analysis of a bacteriophage vB_EcoM_DE7 infecting donkey-derived Escherichia coli.

A lytic bacteriophage vB_EcoM_DE7 (hereafter designated DE7) that could infect donkey-derived Escherichia coli was isolated. The bacteriophage was examined by transmission electron microscopy, and the result showed that DE7 belonged to the family Myoviridae. The microbiological characterization revealed that DE7 was stable over a broad range of pHs (3 ∼10) at 40-50 °C. The latent period was 10 min, and the burst size was 43 PFUs/infected cell. The whole-genome sequencing showed that DE7 was a dsDNA virus and had a genome of 86,130 bp. The genome contained 124 predicted open reading frames (ORFs), 35 of which had known functions, including DNA replication and modification, transcriptional regulation, structural and packaging proteins, and host cell lysis. Twenty tRNA genes were identified, but no genes associated with bacterial pathogenicity, lysogeny and drug resistance were identified. BLASTN analysis revealed that phage DE7 had a high sequence identity (96%) with Salmonella phage vB_SPuM_SP116, but it could not lyse any Salmonella strain tested in this study. DE7 was classified as a Felix O1-like virus based on its general characterization and genomic information. Since phage DE7 exhibited high efficacy in lysing E. coli and lacked genes associated with bacterial virulence, antimicrobial resistance and lysogeny, it could be potentially used to control foal diarrhoea caused by E. coli.

Yu Gan Long Ameliorates Hepatic Fibrosis by Inhibiting PI3K/AKT, Ras/ERK and JAK1/STAT3 Signaling Pathways in CCl4-induced Liver Fibrosis Rats.

Yu Gan Long (YGL) is a Chinese traditional herbal formula which has been reported to attenuate liver fibrosis for many years and we have explored its anti-fibrotic mechanism through blocking transforming growth factor (TGF-ß) in the previous study. But the mechanisms associated with platelet-derived growth factor (PDGF)-BB remain obscure. In this study, we further investigated the mechanism of YGL reducing carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Our results showed that YGL suppressed CCl4-induced upregulation of collagen IV (Col IV), type HI precollagen (PCHI), hyaluronuc acid (HA) and laminin (LN), which are implicated in liver fibrosis. Also, YGL reduced the α-smooth muscle actin (α-SMA) expression, which acts as the indicator of liver fibrosis. Furthermore, YGL decreased the serum levels of hepatic stellate cell (HSC) mitogen PDGF-BB and inflammation cytokines, including TNF-α, IL-1ß, IL-6. Markers involved in liver fibrosis, such as Ras, p-Raf-1, p-ERK1/2, p-JNK, p-P38, p-PI3K, p-AKT, p-JAKl, p-STAT3 were downregulated significantly after treatment with YGL. Our results indicated that YGL ameliorated CCl4-induced liver fibrosis by reducing inflammation cytokines production, and suppressing Ras/ERK, PI3K/AKT, and JAK1/STAT3 signaling pathways, which provided further evidence towards elucidation of the anti-fibrotic mechanism of YGL.

Mandibular molar C-shaped root canals in 5th millennium BC China.

OBJECTIVE: The aim of this study was to analyze the occurrence and variations in C-shaped canals in ancient Chinese teeth and compare the differences of these features between ancient and age-matched modern populations. DESIGN: Approximately 5000-year-old craniofacial bone remains were collected from the fossils of 38 individuals (total: 68 mandibular second molars) excavated from the Jiaojia site. The control group comprised of an equal number of randomly selected modern samples. We used cone-beam computed tomography to scan the mandible along the apex-crown axis and analyzed the canal morphology, based on Fan's categorization criterion, at 2 mm, 5 mm, and 8 mm to the apical level. Grooves on the lingual and buccal sides were also recorded. RESULTS: The proportion of C-shaped roots among ancient samples on the left and right sides were 48.57 % (17/35 teeth) and 54.55 % (18/33 teeth), respectively, and 51.47 % (35/68 teeth) in the total sample. Conversely, in the control group, 44.12 % (15/34) and 38.24 % (13/34) occurred on the left and right sides, respectively, and 41.18 % (28/68) in the total sample. Among the C-shaped canals from the Jiaojia site samples, the classification type changed between two adjacent levels in 84.31 % of samples. Approximately 35 (51.5 %) teeth had a fused root, 20 (29.41 %) had one shallow buccal and one deep lingual groove. The occurrence of C-shape variation was not significantly correlated with time (p＞0.05). CONCLUSIONS: This study identified a high rate of C-shaped root canals among individuals of Jiaojia who lived approximately 5000 years ago.

[Establishment and application of median serum markers for second trimester screening in Qingdao region].

OBJECTIVE: To establish the median of serum markers for second trimester screening in Qingdao region and to assess the influence of median correction on the performance of screening. METHODS: Maternal serum alpha-fetoproteins (AFP), human chorionic gonadotrophin, free beta subunit (ß -HCG) and unconjugated oestriol (uE3) were assayed for prenatal screening of 18 188 singleton pregnancies at 15-20(+ 6) weeks gestation from January 2009 to July 2010. The median of serum markers was calculated based on above results and applied for risk estimation in screening for fetal aneuploidy from August 2010 to March 2011. The screening performance, specified in terms of detection rates (DRs), false positive rates (FPRs) and odds of being affected given a positive result (OAPR) were compared between the two groups. The risks of 45 affected pregnancies detected during the study were estimated with both Caucasian and corrected medians. RESULTS: The average level of AFP in local pregnancies was similar to that of the Caucasian population, whilst ß -HCG and uE3 were respectively 11% and 33% higher than those of Caucasians. The multiple of median (MoM) value was between 0.94 and 1.02 for the dataset based on the corrected median. At a cut-off of l in 270, FPR has decreased from 5.2% to 4.9%, and DR of Down syndrome has increased from 60% to 69.2%, and OAPR has increased from 1:79 to 1:59 when evaluating risk based on the corrected median. For the 45 affected pregnancies, three Down syndrome pregnancies could be missed because their risk estimates were lower than the cut-off level based on Caucasian median. CONCLUSION: It is useful to establish and apply population and laboratory-specific medians in order to improve the performance of prenatal screening and diagnosis.

[Evaluation of Down's syndrome screening methods using maternal serum biochemistry in the second trimester pregnancy].

OBJECTIVE: To provide basis for selecting the suitable method of Down's syndrome biochemical screening in the second trimester pregnancy. METHODS: A total of 30 547 singleton pregnancies between 14 and 20(+ 6) weeks of pregnancy were collected and analyzed for maternal serum alpha-fetoproteins (AFP) and human chorionic gonadotrophin, free beta subunit (beta-HCG) with or without unconjugated estriol (uE3). The screening risks were calculated using the software Lifecycle. The detection rates and the cost of per Down's syndrome detected were calculated and compared. And four different methods were compared in a series of 64 serum samples from Down's syndrome pregnancies. RESULTS: (1) Among the 64 affected cases, the detection rate of Down's syndrome was improved no matter in the double test (DT) or in the triple test (TT) if software Lifecycle (LC) was used to evaluate risks. And it was not suitable to evaluate risks with software 2T-Risks in the triple tests. (2) In the cohort of 30 547 singleton pregnancies, the detection rate of Down's syndrome with project DT-LC, which was double test using AFP and free beta-HCG together with software Lifecycle, and project TT-LC, which was triple test using AFP, free beta-HCG and uE3 together with software Lifecycle, was 56.25% and 57.14%, respectively. The former project was better because it decreased the false positive rate at a lower running cost. CONCLUSION: The DT-LC is an effective screening strategy for second trimester detection of fetal Down's syndrome in mainland China.

Synthesis and biological evaluation of novel 4-benzylpiperazine ligands for sigma-1 receptor imaging.

We report the synthesis and evaluation of 4-benzylpiperazine ligands (BP-CH(3), BP-F, BP-Br, BP-I, and BP-NO(2)) as potential σ(1) receptor ligands. The X-ray crystal structure of BP-Br, which crystallized with monoclinic space group P2(1)/c, has been determined. In vitro competition binding assays showed that all the five ligands exhibit low nanomolar affinity for σ(1) receptors (K(i)=0.43-0.91nM) and high subtype selectivity (σ(2) receptor: K(i)=40-61nM; K(i)σ(2)/K(i)σ(1)=52-94). [(125)I]BP-I (1-(1,3-benzodioxol-5-ylmethyl)-4-(4-iodobenzyl)piperazine) was prepared in 53±10% isolated radiochemical yield, with radiochemical purity of >99% by HPLC analysis after purification, via iododestannylation of the corresponding tributyltin precursor. The logD value of [(125)I]BP-I was found to be 2.98±0.17, which is within the range expected to give high brain uptake. Biodistribution studies in mice demonstrated relatively high concentration of radiolabeled substances in organs known to contain σ(1) receptors, including the brain, lung, kidney, heart, and spleen. Administration of haloperidol 5min prior to injection of [(125)I]BP-I significantly reduced the concentration of radioactivity in the above-mentioned organs. The accumulation of radiolabeled substance in the thyroid was quite low suggesting that [(125)I]BP-I is relatively stable to in vivo deiodination. These findings suggest that the binding of [(125)I]BP-I to σ(1) receptors in vivo is specific.