Reductive Catalytic Difluorocarbene Transfer via Palladium Catalysis.

A palladium-catalyzed reductive difluorocarbene transfer reaction that tames difluorocarbene to couple with two electrophiles has been developed, representing a new mode of difluorocarbene transfer reaction. The approach uses low-cost and bulk industrial chemical chlorodifluoromethane (ClCF2 H) as the difluorocarbene precursor. It produces a variety of difluoromethylated (hetero)arenes from widely available aryl halides/triflates and proton sources, featuring high functional group tolerance and synthetic convenience without preparing organometallic reagents. Experimental mechanistic studies reveal that an unexpected Pd0/II catalytic cycle is involved in this reductive reaction, wherein the oxidative addition of palladium(0) difluorocarbene ([Pd0 (Ln )]=CF2 ) with aryl electrophile to generate the key intermediate aryldifluoromethylpalladium [ArCF2 Pd(Ln )X], followed by reaction with hydroquinone, is responsible for the reductive difluorocarbene transfer.

Illumina high-throughput sequencing for the genome of emerging fowl adenovirus D species and C species simultaneously.

In recent years, clinical cases of inclusion body hepatitis (IBH) and hydropericardium syndrome (HPS) have been emerging and increasing in chicken flocks worldwide. Mixed infections with 2 or more fowl adenovirus (FAdV) serotypes were common in these cases. Herein, we collected a clinical sample that was positive for FAdV from 40-day-old broilers with IBH and HPS symptoms in Shandong province of China and determined the complete genome of FAdVs on the Illumina HiSeq4000 platform. The results showed that the sample contained 2 FAdV strains of D species and C species and named SD1763-1 and SD1763-2 respectively. The genome of SD1763-1 strain was 43,913 nt in length, with a G+C content of 53.51%, whereas SD1763-2 strain was 43,721 nt in length, with a G+C content of 54.87%. Sequence alignment and phylogenetic analysis revealed that strain SD1763-1 was clustered together with serotype 2/11 of FAdV-D, and SD1763-2 was clustered together with FAdV-4. There is no recombination between the genomes of the 2 viruses of FAdV-D and FAdV-C in the present study. This is the first report of obtaining 2 genomic sequences of FAdV strains simultaneously by direct use of deep sequencing in one clinical individual chicken sample, which provided direct evidence for mixed infections of adenovirus serotypes in the clinic and enriched the genome data to explore the geographic biomarkers and virulence signatures of the genus Aviadenovirus.

[Effect of endonasal endoscopic dacryocystorhinostomy combined with lacrimal duct drainage tube implantation in treating lacrimal duct obstruction].

Objective:To investigate the clinical effect of endonasal endoscopic dacryocystorhinostomy（EES-DCR） combined with lacrimal duct drainage tube implantation in treating the patients with lacrimal duct obstruction. Methods: 32 patients （37 eyes） with lacrimal duct obstruction were included into this study, including 1 patient （2 eyes） of functional nasal lacrimal duct obstruction,2 patients （2 eyes） of recurrence after EES-DCR,17 patients （19 eyes） of nasal lacrimal duct obstruction,6 patients （8 eyes） of small lacrimal sac, and 6 patients （6 eyes） of lacrimal duct obstruction. Intraoperative EES-DCR was performed, and lacrimal drainage tubes were implanted from the upper and lower lacrimal points. Septoplasty was performed in 3 patients with nasal septum deviation, and endoscopic sinus surgery was performed in 1 patient with chronic sinusitis.After operation, nasal hormone spraying was performed. During follow-up, the operation effect was evaluated according to the degree of symptom improvement, the patency of lacrimal passage irrigation and the opening state of dacryocystorhinostomy under nasal endoscope. Results:After 3-30 months of follow-up, 29 cases（34 eyes） were cured, 2 cases（2 eyes） were improved, and 1 case（1 eye） was ineffective. The total effective rate was 97.3%（36/37）. No intraorbital, intracranial or nasal complications occurred in all patients. Conclusion:EES-DCR combined with lacrimal duct drainage tube implantation is safe and effective in treating lacrimal duct obstruction. Implantation of lacrimal duct drainage tube can effectively avoid stoma blockage, prevent the adhesion of lacrimal duct, and significantly improve the success rate of surgery.

Effects of MiR-194-5p on the proliferation and invasion of laryngeal cancer cells by regulating the expression of smurf1 and activating the mTOR signaling pathway.

Laryngeal cancer has become the focus of research because of its high incidence rate and mortality rate. However, the research on miR-194-5p in laryngeal cancer is quite rare. The purpose of this study is to explore the effect of miR-194-5p on the proliferation and invasion of laryngeal cancer cells in order to find an effective way to treat laryngeal cancer. The results showed that miR-194-5p could activate the mTOR signaling pathway by regulating the expression of Smurf1, which had an effect on laryngeal cancer cells. The results showed that the absorbance of the miR-194-5p group was 0.38 lower than that of the NC group, which indicated that up-regulation of mir-194-5p could weaken the proliferation of laryngeal cancer cells. In addition, the average number of laryngeal cancer cells in NC and the miR-194-5p groups was 125.2 and 53.8, respectively, which indicated that miR-194-5p could reduce the number of laryngeal cancer cells passing through the basement membrane and their invasion ability.

SNHG5 inhibits the progression of EMT through the ubiquitin-degradation of MTA2 in oesophageal cancer.

A substantial fraction of transcripts are known as long noncoding RNAs (lncRNAs), and these transcripts play pivotal roles in the development of cancer. However, little information has been published regarding the functions of lncRNAs in oesophageal squamous cell carcinoma (ESCC) and the underlying mechanisms. In our previous studies, we demonstrated that small nucleolar RNA host gene 5 (SNHG5), a known lncRNA, is dysregulated in gastric cancer (GC). In this study, we explored the expression and function of SNHG5 in development of ESCC. SNHG5 was found to be downregulated in human ESCC tissues and cell lines, and this downregulation was associated with cancer progression, clinical outcomes and survival rates of ESCC patients. Furthermore, we also found that overexpression of SNHG5 significantly inhibited the proliferation, migration and invasion of ESCC cells in vivo and in vitro. Notably, we found that metastasis-associated protein 2 (MTA2) was pulled down by SNHG5 in ESCC cells using RNA pulldown assay. We also found that SNHG5 reversed the epithelial-mesenchymal transition by interacting with MTA2. In addition, overexpression of SNHG5 downregulated the transcription of MTA2 and caused its ubiquitin-mediated degradation. Thus, overexpression of MTA2 partially abrogated the effect of SNHG5 in ESCC cell lines. Furthermore, we found that MTA2 mRNA expression was significantly elevated in ESCC specimens, and a negative correlation between SNHG5 and MTA2 expression was detected. Overall, this study demonstrated, for the first time, that SNHG5-regulated MTA2 functions as an important player in the progression of ESCC and provide a new potential therapeutic strategy for ESCC.

Ni-Catalyzed Asymmetric Allylation of Secondary Phosphine Oxides.

A nickel-catalyzed asymmetric allylation of secondary phosphine oxides (SPO) for the synthesis of tertiary phosphine oxides (TPO) was realized with high enantioselectivity. The dynamic kinetic asymmetric transformation of SPO was accomplished in the presence of nickel complex. By elucidating the absolute configurations of the reacted SPO starting material and the TPO product, we confirmed that the allylation reaction proceeded through a P-stereo retention process. The protocol represents the first example of synthesizing P-stereogenic phosphine oxides by allylation reaction.

Enhancement of photocatalytic activity of g-C3N4 by hydrochloric acid treatment of melamine.

Modified g-C3N4 samples (g-X, where X corresponds to the number of hours of acid treatment of the melamine) with outstanding photocatalytic performance were prepared by using hydrochloric acid-treated melamine as a precursor and calcining at 550 °C for 2 h. An x-ray diffractometer, field-emission scanning electron microscope, infrared spectrometer, N2 adsorption-desorption test, x-ray photoelectron spectroscopy, and ultraviolet-visible diffuse-reflectance spectroscopy analysis were carried out to characterize the phase composition, microstructure, chemical structure, specific surface area (SSA), chemical states, elemental composition and optical properties of the samples, respectively. The photocatalytic performance of the samples was evaluated by degrading the Rhodamine B (RhB) aqueous solution. The results showed that the crystal structure and vibration bands of melamine changed due to the reaction with hydrochloric acid. The crystallinity and grain size of g-C3N4 in g-X (X = 1, 2, 4, 6, 8, 10) reduced, and the SSA values of g-X increased compared to that of the g-0 sample, which was synthesized from pristine melamine. The g-X samples exhibited excellent photocatalytic activity towards degradation of RhB compared to g-0. The photocatalytic activity of the g-X samples increased gradually as the acid treatment time of the melamine increased from 1 h to 2 h, and then decreased gradually with the extension of the acid treatment time. The rate constant (k) values of g-X are higher than that of g-0. g-2 presented the highest rate constant (k = 0.052 min-1), which was 5.5 times higher than that of g-0. The improved photocatalytic activity of the g-X samples was attributed to the higher SSA value, the appearance of surface defects, the outstanding photo-carrier separation efficiency and stronger light harvesting ability of g-X, with the last two factors being more significant. Acid treatment of melamine is helpful in the preparation of high performance g-C3N4 photocatalyst, and the microstructure and photocatalytic performance of g-C3N4 were affected significantly by the acid treatment time.

GABA regulates the proliferation and apoptosis of MAC-T cells through the LPS-induced TLR4 signaling pathway.

Subacute ruminal acidosis (SARA) can cause rapid lipopolysaccharide (LPS) elevation and milk yield decline in lactating ruminants. LPS has been shown to promote apoptosis and reduce the proliferation of mammary epithelial cells. Previous studies have shown that γ- amino butyric acid (GABA) can enhance production performance, regulating ß-cell apoptosis and proliferation. Whether GABA can regulate apoptosis and proliferation induced by LPS in mammary epithelial cells is unknown. In this paper, we detected the role of GABA on proliferation and apoptosis as well as inflammation induced by LPS in bovine mammary epithelial cells (MAC-T cell line). In addition, we explored the role mechanism of GABA in LPS-induced MAC-T cells response through detecting the NFκB signaling pathway key molecules. The results suggested that GABA reduced the effects of cell apoptosis induced by LPS. Furthermore, GABA inhibited the expression of inflammatory cytokines activated by LPS. More importantly, blocking GABA receptors with its antagonist, GABA could not reduce the expression of inflammatory and pro-apoptotic factors activated by LPS. Notably, GABA significantly decreased the TLR4, NFκB p65, and MyD88 mRNA expression levels that were elevated by LPS. Our data indicated that GABA can improve cell viability and decrease apoptosis induced by LPS, while exerting an anti-inflammatory effect through the NFκB signaling pathway.

Renal transplantation increases angiotensin II receptor-mediated vascular contractility associated with changes of epigenetic mechanisms.

Hypertension is one of the most common complications following renal transplantation, and it increases the risk of graft loss and other cardiovascular diseases. Previous studies have revealed that the use of angiotensin II (Ang II) blockers for preventing and treating hypertension is closely associated with higher survival following renal transplantation. However, the cellular and molecular mechanisms by which the vascular contractility of the recipient is altered in response to Ang II following renal transplantation have not been fully elucidated. In the present study, using the Fisher­Lewis rat kidney transplantation model, the blood pressure (BP) of the conscious transplant recipient was measured following the intravenous administration of Ang II. In addition, the mechanisms underlying the Ang II-mediated vascular contractility via the type 1 and type 2 Ang II receptors (AT1R and AT2R, respectively) in large and small-resistance blood vessels were determined in the recipient after renal transplantation. The results showed that renal transplantation significantly increased the Ang II-stimulated BP of the rats. Additionally, ex vivo contractility experiments using aorta and mesenteric arteries revealed that the contractions induced by Ang II were significantly strengthened in the recipient following renal transplantation, and were associated with an increased intracellular Ca2+ concentration. Losartan almost eradicated the Ang II-induced contractions whereas PD-123319 had no apparent effects on the Ang II-induced contractions in the aorta and mesenteric arteries of the recipient. Furthermore, the expression levels of AT1R but not AT2R were significantly increased in the vasculature of the recipient following renal transplantation, which exhibited a close association with selective DNA demethylation detected in the promoter region of the vascular AT1aR gene. These results indicate that changes of recipient vascular AT1R gene expression, occurring through a mechanism involving DNA methylation, increase the vascular contractility in response to Ang II. This may lead to the increased risk of hypertension following renal transplantation.

[Mutation analysis of 16 mutation spots related to children patients with non-syndromic sensorineural hearing loss].

OBJECTIVE: To explore the clinical signification of screening 16 target deafness mutations in GJB2, GJB3, SLC26A4, WFS1 and mitochondrial DNA 12S rRNA in 135 children patients with non-syndromic sensorineural hearing loss (NSHL) in Zibo City, Shandong province. METHOD: Peripheral blood samples of 135 subjects in the study diagnosed as NSHL were collected; Polymerase chain reaction (PCR) and direct sequencing were used to analyze the 16 mutation spots. RESULT: Sixty-two cases of 135 patients (45.9%, 62/135) were found out to be carries of at least one pathogenic gene mutation. Among them, 24 cases (17.8%, 24/135) had two mutated alleles (homozygote and compound heterozygote), and 38 cases (28.1%, 38/135) were single mutant carriers. Among all the children patients, 30 cases (22. 2%, 30/135) had SLC26A4 mutations, and 19 cases (14.1%, 19/135) had GJB2 mutations. In the study 86 Mutant alleles were detected, and the allele frequency of SLC26A4 c. 766_2A > G and GJB2 c. 235delC was 11.11% (30/270) and 8.5% (23/270) respectively. The allele frequency of SLC26A4 c. 2168A > G and WFS1 c. 2158A > G is 2.6% (7/270). CONCLUSION: SLC26A4 mutation is the primary cause of the patients with NSHL in this study, and GJB2 mutation is the secondary. The most common mutant form is c. 766_2A of SLC26A4, and the second is c. 235delC of GJB2. GJB3 and WFS1 mutations were detected, whereas mtDNA mutations were not found out in this study.

[Diagnosis and therapy for horizontal semicircular canal cupulolithiasis].

OBJECTIVE: By analysing the video-nystagmography findings of positional tests,to evaluate the therapeutic effect of the patients with horikontal semicircular canal cupulolithiasis (HSC-Cup). METHOD: A retrospective study of 36 patients with HSC-Cup. The induced nystagmus in roll tests was recorded by videonystagmography, whose direction, latency, intensity and time characteristics were analysed. All of the 36 patients were treated with lying position avoiding normal side and oral-taken betahistine mesilate tablets. A week later return visits and curative effects evaluation were made. RESULT: Horizontal apogeotropic nystagmus was induced by turning left or right in HSC-Cup roll tests. The time of latency and duration turning to normal and lesion side were(0. 93 ± 0. 65)s and(1. 01 ± 0. 78)s, (100.58 ± 36. 56)s and (118. 65 ± 143. 71)s, which showed no statistically significant difference (P>0. 05). The duration of nystagmus was more than 60 seconds. The intensity of nystagmus turning to normal and lesion side were(45.58 ± 28.71)°/s and (20.42 ± 16. 64)°/s. The intensity turning to normal side was greater than lesion side obviously. The difference was statistically significant (P<0. 05). Twenty-three patients withright HSC-Cup, and 13 patients with left HSC-Cup were taken in count. They were treated with above methods and return visit a week later. Twenty-eight patients (77. 77%) were cured, 36 patients (100. 00%) were improved. There were 4 patients recurrence during the follow-up. CONCLUSION: The direction and duration time of induced nystagmus are available to diagnose the HSC-Cup. The lesion side may determined according to the intensity of induced nystagmus. Lying position avoiding normal side and oral-taken betahistine mesilate tablets is an effective treatment methods for HSC-Cup.

Ethanol extract of Forsythia suspensa root induces apoptosis of esophageal carcinoma cells via the mitochondrial apoptotic pathway.

Forsythia suspensa root is used in the treatment of fever and jaundice in Traditional Chinese Medicine. In the present study, the anti-tumor activity of the ethanolic extract of Forsythia suspensa root (FSREE) against esophageal carcinoma cells was investigated in vitro and in vivo and its anti-cancer mechanism was examined. The results revealed that FSREE, rather than Forsythia suspensa ethanolic extracts from the leaf (FSLEE) and fruit (FSFEE) exhibited marked anti-tumor activity towards human esophageal cancer cells. FSREE induced cancer cell apoptosis and growth arrest by downregulating B­cell lymphoma (Bcl)­2, Bcl­extra large and myeloid cell leukemia 1, while upregulating Bcl­2­associated X protein, Bcl­2 antagonist of cell death and phorbol­12­myristate­13­acetate­induced protein 1. This led to the activation of poly(ADP ribose) polymerase, caspase­3 and caspase­9, but not caspase­8. Furthermore, the anti-cancer activity of FSREE was associated with a decreased level of phosphorylated Janus kinase/signal transducer and activator of transcription 3 and extracellular­signal­regulated kinase signaling activity. It was also observed that the levels of cytochrome c were elevated in the cytoplasm, accounting for the loss of mitochondrial membrane potential in the TE­13 cells upon treatment with FSEER. In addition, FSEER inhibited the growth of esophageal cancer cells in xenograft models and no detectable toxicity was present in the lung or liver tissues. These observations provided further evidence of the anti-tumor effect of FSEER and may be of importance to further examine the potential role of Forsythia suspensa root as a therapeutic agent in esophageal carcinoma therapy.

[Analysis of directional preponderance of caloric test in evaluation of vestibular dynamic compensation].

OBJECTIVE: To analyze the value of directional preponderance (DP) in vestibular dynamic compensation evaluation. METHODS: One hundred fifty-five patients with sudden deafness accompanied vertigo were asked to accept routine vestibular tests including the spontaneous nystagmus (SN) and caloric test with video-nystagmography. DP, SN and unilateral weakness (UW) were selected as the observation parameters. Then the correlation analysis between DP, SN, UW and course of disease were investigated respectively. The change characteristic of the three parameters was also analyzed in the course of vestibular compensation. RESULTS: Of the 155 patients, there were negative correlations between SN, DP and course of disease (r(s) = -0.386, r(s) = -0.424, P < 0.05), positive correlation between SN and DP (r(s) = 0.543, P < 0.05), but no correlation between UW and course of disease (r(s) = 0.004, P > 0.05), and also positive correlation (r(s) = 0.274, P < 0.05) between DP and UW. According to three parameters were positive or negative, three main groups (DP+UW+SN+, DP+UW+SN- and DP-UW+SN-) in DP, UW, SN. The course of disease in three main groups was positively skewed distribution. Median was 6 days, 10 days and 20 days respectively. Through Kruskal-Wallis Test, chi(2) = 24.63, P < 0.05, there was statistical significance among the above three main groups. CONCLUSIONS: DP keeps on changing in the acute stage, static and dynamic compensation stage of peripheral vestibular disease. This indicates that DP can be considered as an objective evaluation index of vestibular dynamic compensation and as a guidance of the vestibular rehabilitation evaluation.

[To analyze the screening value of vestibular monothermal caloric tests].

OBJECTIVE: To investigate the screening value and the reliability of the monothermal caloric tests (MCT) in evaluating vestibular function. METHOD: One thousand and four hundred and six vertigo patients were divided into two groups. Seven hundred and five cases were stimulated by different temperature air from cold to warm. The caloric test sequence of other 701 cases was opposite. The first stimulated cold or warm air test was regarded as monothermal cold caloric test (MCCT) or monothermal warm caloric test (MWCT). The unilateral weakness (UW) and directional preponderance (DP) of the bithermal caloric tests (BCT) and the UW of the MCT were calculated. By defining the BCT results as the standard, the sensitivity, specificity, Youden's index and kappa were calculated. RESULT: Four hundred and twenty-eight showed abnormal BCT and MCCT. One hundred and forty-five showed normal BCT and MCCT. 85, 47 showed isolated abnormal BCT and abnormal MCCT respectively. The sensitivity of the MCCT was 83.4%, specificity was 75.5%, Youden's index was 0.589 and kappa was 0.555 (P<0.01). Four hundred and twenty-nine showed abnormal BCT and MWCT, 130 showed normal BCT and MWCT. 82, 60 showed isolated abnormal BCT and abnormal MWCT respectively. The sensitivity of the MWCT was 84.0%, specificity was 68.4%, Youden's index was 0.524 and kappa was 0.505 ( P<0.01). The sensitivity of the MCCT and MWCT were 86.9% and 86.9% respectively when cases accompanied by spontaneous nystagmus (SN) were excluded. The sensitivity of the MCCT and MWCT were 89.3% and 88.1% respectively when cases with abnormal DP were excluded. CONCLUSION: The high false-positive and false-negative rate of the MCT limit the usefulness as a screening test due to the influence of DP and SN.

[Rapid determination of formaldehyde in food packaging material by oscilloscopic polarography].

The polarographic behavior of the reaction product of formaldehyde and phenyldrazine hydrochloride on the drop mercury electrode was investigated in a medium of 0.01 mol/L H3PO4 and sensitive second order polarographic reduction wave was obtained at -0.76 V (vs. SCE). The optimum conditions and disturbance of other co-existing substances were also studied, and were compared with those of national standard method. In the study, the detectable range, detection limit, recovery rate, relative standard deviation(RSD) of the improved method were 0.005-0.25 mg/L, 0.005 mg/L, 92.3%-104.6%, 1.1%-3.0% respectively, revealing the accordance with the national standard method.