S-9-PAHSA's neuroprotective effect mediated by CAIII suppresses apoptosis and oxidative stress in a mouse model of type 2 diabetes.

BACKGROUND: With the rapidly increasing prevalence of metabolic diseases such as type 2 diabetes mellitus (T2DM), neuronal complications associated with these diseases have resulted in significant burdens on healthcare systems. Meanwhile, effective therapies have remained insufficient. A novel fatty acid called S-9-PAHSA has been reported to provide metabolic benefits in T2DM by regulating glucose metabolism. However, whether S-9-PAHSA has a neuroprotective effect in mouse models of T2DM remains unclear. METHODS: This in vivo study in mice fed a high-fat diet (HFD) for 5 months used fasting blood glucose, glucose tolerance, and insulin tolerance tests to examine the effect of S-9-PAHSA on glucose metabolism. The Morris water maze test was also used to assess the impact of S-9-PAHSA on cognition in the mice, while the neuroprotective effect of S-9-PAHSA was evaluated by measuring the expression of proteins related to apoptosis and oxidative stress. In addition, an in vitro study in PC12 cells assessed apoptosis, oxidative stress, and mitochondrial membrane potential with or without CAIII knockdown to determine the role of CAIII in the neuroprotective effect of S-9-PAHSA. RESULTS: S-9-PAHSA reduced fasting blood glucose levels significantly, increased insulin sensitivity in the HFD mice and also suppressed apoptosis and oxidative stress in the cortex of the mice and PC12 cells in a diabetic setting. By suppressing oxidative stress and apoptosis, S-9-PAHSA protected both neuronal cells and microvascular endothelial cells in in vivo and in vitro diabetic environments. Interestingly, this protective effect of S-9-PAHSA was reduced significantly when CAIII was knocked down in the PC12 cells, suggesting that CAIII has a major role in the neuroprotective effect of S-9-PAHSA. However, overexpression of CAIII did not significantly enhance the protective effect of S-9-PAHSA. CONCLUSION: S-9-PAHSA mediated by CAIII has the potential to exert a neuroprotective effect by suppressing apoptosis and oxidative stress in neuronal cells exposed to diabetic conditions. Furthermore, S-9-PAHSA has the capability to reduce fasting blood glucose and LDL levels and enhance insulin sensitivity in mice fed with HFD.

Analysis of the clinical diagnosis and treatment of fetal meconium peritonitis.

BACKGROUND: The purpose of this study was to improve diagnostic and therapeutic standards by examining the clinical features, treatment, and prognosis of fetal meconium peritonitis (FMP), as well as the diagnostic efficacy of ultrasound for FMP. METHODS: The clinical data of 41 infants and pregnant women diagnosed with meconium peritonitis (MP) and treated at the Fujian Maternal and Child Health Hospital from January 2013 to January 2020 were analyzed retrospectively. Clinical data, imaging data, complications, treatment strategies, pregnancy outcomes, neonatal prognoses, and follow-up outcomes were all analyzed. RESULTS: The MP prenatal diagnosis rate was 56.1% (23/41), the neonatal surgery rate was 53.7% (22/41), and the survival rate was 85.4% (35/41). Intraperitoneal calcification (23 pregnant women, 56.1%), intestinal dilatation (13 pregnant women, 31.7%), peritoneal effusion (22 pregnant women, 53.7%), intraperitoneal pseudocyst (7 pregnant women, 17.1%), and polyhydramnios were diagnosed via prenatal ultrasound (18 pregnant women, 43.9%). Twenty-two pregnant women were assigned to the surgical treatment (operation) group, while 18 were assigned to the conservative treatment group. In the operation group, there were 9 cases of ileal atresia (40.9%), 7 cases of jejunal atresia (31.8%), 2 cases of atresia at the jejunum-ileum junction (9.1%), 2 cases of ileal perforation (9.1%), 1 case of ileal necrosis (4.5%), and 1 case of adhesive obstruction (4.5%). There was no statistically significant difference (p > .05) in the occurrence of various prenatal ultrasound findings by etiology. CONCLUSION: Multiple prenatal ultrasound markers have been identified for MP. To improve the efficacy of newborn treatment for FMP and reduce neonatal mortality, dynamic monitoring of ultrasound image alterations and strengthened integrated perinatal management are necessary.

Assessment of oral emergency services during COVID-19: a retrospective study of 14,885 cases in Shanghai.

BACKGROUND: To assess the impact of coronavirus disease-2019 (COVID-19) in its outbreak stage (Spring Festival in 2020) on oral emergency services. METHODS: Oral emergency cases in Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, during the Spring Festival after the outbreak of the COVID-19 epidemic in 2020 were collected and compared with those in 2018 and 2019. Electronic medical records including the visited department, age, sex, time, date, region, and diagnosis were collected and analyzed. The results were statistically analyzed using Pearson's Chi-square test and one-way analysis of variance (ANOVA). RESULTS: Compared with that in 2018 and 2019, the total number of patients decreased during the Spring Festival in 2020 (p < 0.001), but the proportions of patients visiting Oral Surgery and Oral, Head, and Neck Oncology Emergency departments increased. The average age of patients increased, and the number of night visits decreased. Toothache diseases involving endodontic and periodontal diseases increased, while the proportion of maxillofacial trauma decreased. The wasn't a linear association between diagnosis or genders (P > 0.001) across years. However, a linear-by-linear association between age groups and years, visited departments and years were observed (P < 0.001). CONCLUSIONS: The study revealed that the transmission of COVID-19 affected the patient population and structure of disease types and oral services in 2020 during the Spring Festival, compared with those in the previous two years. The visits to oral emergency departments and the proportions of patients who were children and adolescents reduced; meanwhile, the percentage of the elderly people increased during the outbreak of COVID-19. The clear trend of age groups and visiting divisions could be used as a marker to reflect the severity of the COVID-19 pandemic. These results may serve as a reference for dental practitioners involved in oral emergency services and to allocate the limited emergency health resources.

Design and synthesis of photoaffinity-based probes for labeling ß-glucuronidase.

ß-Glucuronidase (GUSB) plays an important role in human physiological and pathological activities. The activity level of GUSB is closely related to human health and diseases. It is imperative to detect the activity of GUSB for related disease diagnosis and treatment. However, exactly evaluating the activity of GUSB in complicated biological system remains a challenge. In this study, we developed photoaffinity-based probes (AfBPs) equipped with photosensitive benzophenone group for labeling active GUSB. Through molecule docking, we predicted the binding model of the AfBPs and GUSB, and the obtained results suggested thermodynamically favorable binding. The AfBPs indicated high efficiency and showed dose-/time-dependent labeling of Escherichia coli (E. coli) GUSB. The application of AfBPs toward GUSB provides a powerful tool to study the activity of target enzymes and contributes to huge potential of enzyme inhibitor discovery and biomedical diagnostics.

[LC-MS fingerprint and multi-indicator components analysis of classical formula Gualou Xiebai Banxia Decoction].

This study developed an optimal pre-processing technique for the reference substance of the classic formula Gualou Xiebai Banxia Decoction(GXBD) and established a comprehensive quality control method for GXBD reference substance to provide a reference for its overall quality evaluation. The authors prepared 15 batches of GXBD samples and innovatively used the extracted ion chromatogram under the base peak chromatogram mode to establish a liquid chromatography-mass spectrometry(LC-MS) fingerprint, identify characteristic peaks, and perform quantitative analysis of indicator components. The yield of the 15 batches of GXBD samples ranged from 50.28% to 76.20%. In the positive ion mode, 12 common characteristic peaks were detected in the LC-MS fingerprint, and the structures of five common peaks were identified by comparison with reference standards. The similarity between the fingerprint profiles of different batches of samples and the reference fingerprint profile ranged from 0.920 to 0.984. Finally, liquid chromatography-triple quadrupole mass spectrometry(LC-QQQ/MS) in multiple reaction monitoring(MRM) mode was used to determine the content of eight indicator components in GXBD, including loliolide, chrysoeriol, rutin, cucurbitacin D, macrostemonoside Ⅰ, 25S-timosaponin B Ⅱ, 25R-timosaponin B Ⅱ, and peptide proline-tryptophan-valine-proline-glycine(PWVPG). The method established in this study can reduce matrix interference in the compound, and it has good accuracy, stability, and practical value. It effectively reflects the quality attributes of GXBD samples and can be used for the comprehensive quality control of GXBD.

p21 promotes gemcitabine tolerance in A549 cells by inhibiting DNA damage and altering the cell cycle.

Gemcitabine is one of the most widely used chemotherapy drugs for advanced malignant tumors, including non-small cell lung cancer. However, the clinical efficacy of gemcitabine is limited due to drug resistance. The aim of the present study was to investigate the role of p21 in gemcitabine-resistant A549 (A549/G+) lung cancer cells. IC50 values were determined using a Cell Counting Kit-8 (CCK-8) assay. mRNA and protein expression levels of genes were measured by reverse transcription-quantitative PCR and western blotting, respectively. The cell cycle distribution and apoptosis rate were analyzed by flow cytometry. DNA damage in cells was evaluated by single-cell gel electrophoresis. The results of western blot analysis and the CCK-8 assay demonstrated that the expression of p21 was higher in A549/G+ cells than in gemcitabine-sensitive cells. Knockdown of p21 expression in gemcitabine-resistant cells sensitized these cells to gemcitabine (with the IC50 decreasing from 84.2 to 26.7 µM). Cell cycle analysis revealed different changes in the cell cycle distribution in A549/G+ cells treated with the same concentration of gemcitabine, and decreased expression of p21 was shown to promote G1 arrest. The apoptosis assay and comet assay results revealed that decreased p21 expression resulted in accumulation of unrepaired DNA double-strand breaks (DSBs) and induction of apoptosis by gemcitabine. The present study demonstrated that knockout of p21 mRNA expression in A549/G+ cells promotes apoptosis and DNA DSB accumulation, accompanied by G1 arrest. These results indicated that p21 is involved in regulating the response of A549 cells to gemcitabine.

MiR-17- 5p/RRM2 regulated gemcitabine resistance in lung cancer A549 cells.

The main objective of this study is to investigate the regulatory roles of the miR-17-5p/RRM2 axis in A549/G+ cells' gemcitabine resistance. The cell viability was determined using CCK8 and clonogenic assays. Gene expression level analysis by RT-qPCR and Western blotting. Cell cycle analysis by flow cytometry. The dual luciferase activity assay was used to verify the target gene of miR-17-5p. In gemcitabine-resistant cell line A549G+, the drug resistance decreased after up-regulation of MiR-17-5p expression. The proportion of cell cycle G1 phase increased, and the S phase decreased. The expression level of cell cycle-related proteins CCNE1, CCNA2, and P21 decreased. The opposite results emerged after the down-regulation of MiR-17-5p expression in gemcitabine-sensitive cell line A549G-. The expression levels of PTEN and PIK3 in A549G+ cells were higher than in A549G-cells, but p-PTEN was lower than that in A549G-. After up-regulating the expression of MiR-17-5p in A549G+, the expression levels of p-PTEN increased, and the expression level of p-AKT decreased. After down-regulating miR-17-5p expression, the opposite results emerged. The dual-luciferase reporter assay and restorative experiments proved that RRM2 is one of the target genes for MiR-17-5p. Our results suggested that the miR-17-5p/RRM2 axis could adjust gemcitabine resistance in A549 cells, and the p-PTEN/PI3K/AKT signal pathway might be involved in this regulatory mechanism.

[Effect of low magnitude tension on the inflammatory response of periodontal ligament cells induced by isoproterenol].

PURPOSE: To investigate the effect of tension on the inflammatory response of human periodontal ligament cells (PDLCs) induced by isoproterenol (ISO) and its molecular mechanism. METHODS: Human PDLCs were cultured in vitro and stimulated with a certain concentration of ISO(0.01, 0.1, 1 µmol/L) for 24 h. Cyclic tensile strain with different degrees of elongation (5%, 10% and 15%) were applied. The expression of IL-1ß and IL-6 mRNA in PDLCs was detected by real-time quantitative PCR(RT-qPCR). The protein expression of p-PERK, PERK, p-eIF2α, eIF2α and ATF4 related to ER stress was detected by Western blot. The expression of PERK gene in PDLCs was knocked down by cell transfection technique, and the expression of IL-1ß and IL-6 mRNA in PDLCs with low expression of PERK was detected by RT-qPCR under the stimulation of ISO and low magnitude tension. Statistical analysis was conducted with SPSS 22.0 software package. RESULTS: ISO induction could significantly up-regulate the IL-1ß and IL-6 mRNA expression in PDLCs(P＜0.05). Compared with the control group, the expression of IL-1ß and IL-6 mRNA in PDLCs induced by ISO was inhibited by low magnitude tension, and the difference was statistically significant(P＜0.05). Western blot results showed that low magnitude tension could inhibit the ISO-stimulated phosphorylation of PERK and eIF2α and the expression of ATF4（P＜0.05）. Compared with the negative control group, IL-1ß and IL-6 mRNA expression was decreased in the ISO-stimulated PDLCs silenced by PERK gene. CONCLUSIONS: Tension with 5% degrees of elongation may inhibit ISO-stimulated periodontal inflammatory response through endoplasmic reticulum stress pathway.

[Evaluation of the effect of digital crown extension guide in aesthetic restoration of anterior teeth].

PURPOSE: To evaluate the clinical effect of three-dimensional digital smile design (3D-DSD) combined with double positioning crown extension guide in aesthetic restoration of anterior teeth. METHODS: Twenty patients who needed aesthetic crown lengthening and full crown restoration of upper anterior teeth were selected and randomly divided into the experimental group and control group, with 10 cases in each group. The experimental group carried out 3D-DSD, after confirming the plan, 3D printed double positioning crown extension guides were used to guide aesthetic crown lengthening, and full crown was completed 3 months after operation. The control group used traditional aesthetic crown lengthening and full crown restoration. PES/WES evaluation was performed before operation, three months and six months after operation. Visual analogue scales(VAS) were used to evaluate patient satisfaction 6 and 7 months after surgery, and the repeatability evaluation of VAS was conducted. The correlation between PES/WES score and overall satisfaction was analyzed 6 months after operation. SPSS 23.0 software package was used for statistical analysis. RESULTS: The PES/WES scores of the two groups of patients at 3 months and 6 months after operation were higher than those before operation(P＜0.05). The two groups showed that the scores of the experimental group were significantly higher than those of the control group for PES 3 months after operation, PES and WES 6 months after operation(P＜0.05).Satisfaction survey results showed that the intra-group correlation coefficient of the two VAS results was 0.956(P＜0.05),and crown length-to-width ratio, smile curve, personality characteristics, patient participation and overall satisfaction in the experimental group were better than those of the control group(P＜0.05).The results of Speraman correlation analysis showed that PES and WES scores at 6 months after operation were positively correlated with overall satisfaction (rs1=0.905, P＜0.001; rs2=0.460, P=0.041). CONCLUSIONS: 3D digital smile design combined with double positioning crown extension guide guides the anterior aesthetic crown lengthening and restoration treatment, which can improve the effect of pink and white aesthetics after treatment and patient satisfaction.

Computer simulation of hypothetical hydrogen ordered structure of ice XIX.

A new ice phase, ice XIX, was discovered in 2018, and is the second hydrogen-ordered polymorph of hydrogen-disordered ice VI. The first hydrogen-ordered polymorph of ice VI is ice XV, and ices XIX, VI, and XV comprise a unique triplet group in the ice family. However, the exact crystal structure of ice XIX has not been confirmed. We constructed four possible conformations of ice XIX using neutron diffraction data obtained by Gasser et al. We then optimized these structures and simulated their Raman scattering spectra using first-principles density functional theory. By comparing these simulated spectra with the experimental Raman scattering spectra, we were able to exclude the existence of a ferroelectric structure with the space group Cc. The other three candidate structures are in good agreement with the experimental Raman scattering data; two of them are ferroelectric structures with the space group P21; and the last one is a weak ferroelectric structure with the space group Cc. We proposed that the partially hydrogen-ordered structure of ice XIX maybe a mixing of several hydrogen-ordered structures.

Comparative Analysis of the Hydrogen Bond Vibrations of Ice XII.

It is difficult to theoretically study the vibrational spectrum of hydrogen-disordered ice XII compared with its hydrogen-ordered counterpart, ice XIV. We constructed a 24-molecule supercell of ice XII to mimic its real structure. We focused on hydrogen bond (HB) vibrational modes in the translation band using first-principles density functional theory (DFT). Our simulated results were in good agreement with inelastic neutron scattering experiments. We found that the optical vibrational modes of HBs are composed of three main components. These are cluster vibrations in the lowest-frequency region, four-bond HB vibrations in the highest-frequency region, and two-bond modes in between. Although the experimentally recorded curve of ice XII is smooth in the translation region, our results support the proposal that two types of intrinsic HB vibrational modes are common in the ice family.

Comparative Analysis of Hydrogen-Bonding Vibrations of Ice VI.

It is difficult to investigate the hydrogen-bonding dynamics of hydrogen-disordered ice VI. Here, we present a comparative method based on our previous study of its counterpart hydrogen-ordered phase, ice XV. The primitive cell of ice XV is a 10 molecule unit, and the vibrational normal modes were analyzed individually. We constructed an 80 molecule supercell of ice VI to mimic the periodic unit and performed first-principles density functional theory calculations. As the two vibrational spectra show almost identical features, we compared the molecular translation vibrations. Inspired by the phonon analysis of ice XV, we found that the vibrational modes in the translation band of ice VI are classifiable into three groups. The lowest-strength vibration modes represent vibrations between two sublattices that lack hydrogen bonding. The highest-strength vibration modes represent the vibration of four hydrogen bonds of one molecule. The middle-strength vibration modes mainly represent the molecular vibrations of only two hydrogen bonds. Although there are many overlapping stronger and middle modes, there are only two main peaks in the inelastic neutron scattering (INS) spectra. This work explains the origin of the two main peaks in the far-infrared region of ice VI and illustrates how to analyze a hydrogen-disordered ice structure.

A Clinical Analysis of the Diagnosis and Treatment of Fetal Sacrococcygeal Teratomas.

OBJECTIVE: The present study aims to discuss the clinical features, treatment, and prognosis of fetal sacrococcygeal teratomas (SCTs) to improve the standard of diagnosis and treatment. METHODS: The clinical data of 15 pregnant females with fetal SCT, admitted to Fujian  Maternity and Child Health Hospital from January 2013 to January 2020, were retrospectively analyzed with respect to clinical characteristics, imaging features, complications, treatment options, and pregnancy outcomes. RESULTS: The 15 cases of fetal SCT were all detected by color ultrasonography. There were two cases of cystic tumors and 13 cases of solid cystic tumors. In terms of tumor blood supply, there was one case without blood flow signal, eight cases with little blood flow signal, and six cases with abundant blood flow. At the time of delivery, there were two cases with a tumor diameter less than 5 cm, five cases with a diameter of 5-10 cm, and eight cases with a diameter of more than 10 cm. In terms of tumor shape and location, there were two cases of type I, ten cases of type II, and three cases of type III. There were six cases with an increased fetal heart to chest ratio, four cases of fetal edema, three cases of placental edema, four cases of excessive amniotic fluid, one case of insufficient amniotic fluid, three cases of fetal distress, one case of stillbirth, two cases of gestational diabetes mellitus, two cases of mirror syndrome, and two cases of postpartum hemorrhage. According to the pathological diagnosis, there were seven cases of mature teratoma, seven cases of immature teratoma, and one case of mixed germ cell tumor. There were six cases of induced delivery, nine cases of cesarean section, one case of premature birth, and two cases of mild neonatal asphyxia. CONCLUSION: Fetal SCT was generally diagnosed by prenatal ultrasonography. The tumor blood supply, growth rate, size, nature of the tumor, clinical type, pathology, and maternal-fetal complications are all closely correlated with the prognosis. The timing and manner of the termination of pregnancy should be determined on the basis of the pregnant female, the fetus, and the tumor.

Identification of Proteus genomic island 2 variants in two clonal Proteus mirabilis isolates with coexistence of a novel genomic resistance island PmGRI1.

OBJECTIVES: To characterize the MDR genomic islands (GIs) in Proteus mirabilis isolates. METHODS: Two P. mirabilis strains (C55 and C74) of chicken origin were subjected to WGS (HiSeq and PacBio) and the MDR GIs were determined. RESULTS: P. mirabilis strains C55 and C74 are clonal strains and harbour different Proteus genomic island 2 (PGI2) variants (PGI2-C55 and PGI2-C74). The MDR region of PGI2-C55 is composed of two class 1 integrons, separated by a region containing seven copies of IS26 and eight resistance genes, including blaCTX-M-3 and fosA3. The region in PGI2-C74 is a complete In4-type class 1 integron, harbouring five gene cassettes (dfrA16, blaCARB-2, aadA2, cmlA1 and aadA1). In addition, C55 and C74 carry an SXT/R391 integrative and conjugative element (ICEPmiJpn1), harbouring blaCMY-2, and a novel 50.46 kb genomic resistance island named PmGRI1-C55. PmGRI1-C55 harbours a tyrosine-type recombinase/integrase that might be responsible for the integration of PmGRI1-C55 at the 3' end of tRNA-Sec. It carries an MDR region derived from Tn2670 that harbours a Tn21 region and carries six resistance genes (catA1, blaTEM-1b, aphA1a, sul2, strA and strB). Blast analysis showed diverse PmGRI1 variants in P. mirabilis and Escherichia coli strains. CONCLUSIONS: The finding of the two new PGI2 variants highlights that the homologous recombination between shared components of class 1 integrons and transposition by IS26 promote the diversity of MDR regions in PGI2. PmGRI1 is a new GI that carries various resistance genes identified in P. mirabilis and E. coli.

An analysis of the maternal and infant outcomes in the delayed interval delivery of twins.

OBJECTIVE: To investigate the treatment methods used for the delayed interval delivery of twins and to evaluate the maternal and infant outcomes. MATERIALS AND METHODS: The clinical data of 5 patients that underwent delayed interval delivery of twins at Fujian Maternal and Child Health Hospital from 2014 to 2018 were analyzed. The gestational ages at delivery, obstetrical management, the interval between deliveries, and the maternal and child outcomes were analyzed. RESULTS: The average gestational age at delivery of the first child was 23+3 weeks (range: 20+1-30+2 weeks). All 5 mothers underwent high ligation of the umbilical cord and received prophylactic antibiotic treatment. Tocolytics were administered to 3 patients, 1 of which had previously undergone cervical cerclage placement. No tocolytics were administered to the remaining 2 patients. The average delayed delivery time was 15 days (range: 3-31 days). The second child was delivered at an average gestational age of 25+5 weeks (range: 20+4-31+3 weeks). The average birth weight of the second twin was 957 g (range: 360-1930 g). Three of the patients delivered vaginally, 1 delivered via a cesarean section, and 1 required a breech extraction. Of these deliveries, there were 3 neonatal survivals. Pathogens were detected in the cervical secretion cultures in all cases. Two patients had grade 2 placental abruption, 5 had an intrauterine infection, 1 developed sepsis, 1 developed postpartum hemorrhage, and 5 showed a placenta adherence. CONCLUSION: The delayed interval delivery of twins is a unique treatment for patients experiencing a twin pregnancy. Successful performance of this method can improve the survival rates for the second twin and improve prognosis. However, careful attention is required when performing this treatment to prevent and treat possible complications that may arise during the procedure.

Draft genome sequence of a multidrug-resistant Salmonella enterica serotype Kentucky ST198 with chromosomal integration of blaCTX-M-14b isolated from a poultry slaughterhouse in China.

OBJECTIVES: The aim of this study was to characterise the draft genome sequence of a multidrug-resistant (MDR) Salmonella enterica serotype Kentucky strain (XJ9S) isolated from a poultry slaughterhouse in China. METHODS: The genome was sequenced using an Illumina HiSeq platform and was assembled using SPAdes_3.12.0. The CGE Bacterial Analysis Pipeline was used to identify the sequence type (ST) as well as the presence of antimicrobial resistance genes (ARGs) and plasmids in strain XJ9S. Gaps among contigs that carried MDR Salmonella genomic island 1 (SGI1) fragments were filled in by PCR linkage and sequencing. RESULTS: The draft genome of strain XJ9S was assembled into 54 contigs with a total assembly size of 4 785 059 bp. XJ9S belonged to ST198 and harboured five acquired ARGs [blaCTX-M-14b, sul1, tetA(A), aacCA5 and aadA7]. The blaCTX-M-14b gene was located on a 2849-bp ISEcp1-mediated translocatable unit inserted in the chromosome. The other four acquired ARGs were carried by a new variant of SGI1 (SGI1-XJ9S; 38 593 bp) belonging to the SGI1-K group. Moreover, point mutations in the quinolone resistance-determining region (QRDR) were found at positions 83 (Ser83Phe) and 87 (Asp87Gly) of GyrA and at position 80 (Ser80Ile) of ParC. CONCLUSION: In this study, a new SGI1 variant (SGI1-XJ9S) was characterised for the first time. The draft genome sequence of S. Kentucky ST198 strain XJ9S isolated from a poultry slaughterhouse provides valuable information for tracing the potential spread of this MDR clone from poultry product processing to consumption, and even to humans.

Novel motif is capable of determining CCR and CCR-like proteins based on the divergence of CCRs in plants.

Cinnamoyl-coenzyme A reductases (CCRs) have been reported as key enzymes involved in monolignol biosynthesis. In this study, a motif-aware workflow based on a new signature motif effectively distinguished CCRs from CCR-like proteins. The divergence of CCRs and CCR-like sequences in Populus tomentosa Carr, Panicum virgatum L, Oryza sativa L and Selaginella moellendorffii Hieron suggests that NWYCY is not efficient for CCR recognition. The novel motif H202(X)2K205 (CCR-SBM or CCR substrate binding motif) was introduced to distinguish between CCRs and CCR-like proteins. The site-directed mutant R205K in Os(I)CCR-like and H202 in PtoCCR7 resulted in the rescue and loss of activity, respectively, further validating the fact that CCR-SBM is critical for maintaining CCR activity. The molecular docking using feruloyl-cinnamoyl-coenzyme A (CoA) as the ligand and binary PhCCR-NADP structures as receptors indicated an interaction between H202 and K205 with CoA moiety. The genuine CCRs and CCR-like proteins from several angiosperms and gymnosperms were screened using a motif-aware workflow and were validated using a biochemical assay. Our results suggest that the motif-aware workflow is efficient and effective for the identification of CCRs and CCR-like proteins in land plants and can be used as a more accurate way of identifying genuine CCRs among land plants.

IS26-Mediated Genetic Rearrangements in Salmonella Genomic Island 1 of Proteus mirabilis.

Salmonella genomic island 1 (SGI1) is an integrative mobilizable element integrated into the chromosome of bacteria, which plays an important role in the dissemination of antimicrobial resistance genes. Lots of SGI1 variants are found mainly in Salmonella enterica and Proteus mirabilis. In this study, a total of 157 S. enterica and 132 P. mirabilis strains were collected from food-producing animals in Sichuan Province of China between December 2016 and November 2017. Detection of the SGI1 integrase gene showed that three S. enterica and five P. mirabilis strains were positive for SGI1, which displayed different multidrug resistance profiles. Five different SGI1 variants, including two novel variants (SGI1-PmBC1123 and SGI1-PmSC1111), were characterized by whole genome sequencing and PCR linkage. In two novel SGI1 variants, IS26-mediated rearrangements resulted in large sequence inversions of the MDR regions extending outside the SGI1 backbone. The sul3-type III class 1 integron (5'CS-sat-psp-aadA2-cmlA1-aadA1-qacH-IS440-sul3) and gene cassettes aac(6')-Ib-cr-bla OXA- 1-catB3-arr-3 are found in SGI1-PmSC1111. Mobilization experiments indicated that three known variants were conjugally mobilized in trans to Escherichia coli with the help of a conjugative IncC plasmid. However, the two novel variants seemed to lose the mobilization, which might result from the sequence inversion of partial SGI1 backbone. The identification of the two novel SGI1 variants in this study suggested that IS26-mediated rearrangements promote the diversity of SGI1.

General Mild Reaction Creates Highly Luminescent Organic-Ligand-Lacking Halide Perovskite Nanocrystals for Efficient Light-Emitting Diodes.

The presence of labile bulky insulating hydrocarbon ligands in halide perovskite nanocrystals (NCs) passivates surface traps but concurrently makes charge transport difficult in optoelectronic devices. Early efforts routinely rely on the replacement of long-chain ligands with short-chain cousins, leading to notable changes in NC's sizes and photophysical properties and thus making it hard to obtain devices with nearly designed emissions. Here we report a general solution-phase ligand-exchange strategy to produce organic-ligand-lacking halide perovskite NCs with high photoluminescence (PL) quantum yields and good stability in ambient air. We demonstrate that the ligand exchange can be achieved by a well-controlled mild reaction of thionyl halide with the carboxylic and amine groups on the NC's surface, resulting in nearly dry NCs with well-passivated surfaces and almost unaltered emission characteristics. Consequently, we achieve exceptionally high-performance blue perovskite NC light-emitting diodes (LEDs) with an external quantum efficiency of up to 1.35% and an extremely narrow full width at half-maximum of 14.6 nm. Our work provides a systematic framework for preparing high-quality organic-ligand-lacking perovskite NC inks that can be directly cast as films featuring effective charge transport, thereby providing the foundation for further development of a wide range of efficient perovskite optoelectronic devices.

Computational Analysis of Exotic Molecular and Atomic Vibrations in Ice XV.

It is always difficult to assign the peaks of a vibrational spectrum in the far-infrared region. The two distinct peaks seen in many ice phases are still a mystery to date. The normal modes of ice XV were calculated using the CASTEP code based on first-principles density functional theory. On the basis of vibrational modes analysis, we divided the translational modes into three categories: four-bond vibrations, which have the highest energy levels; two-bond vibrations, which have medium levels of energy; and relative vibrations between two sublattices, which have the lowest energy. Whale et al. found that some intramolecular stretching modes include the isolated vibration of only one O-H bond, whereas the others do not vibrate in ice XV. We verified this phenomenon in this study and attributed it to local tetrahedral deformation. Analysis of normal modes, especially in the translation and stretching band of ice XV, clarified the physical insights of the vibrational spectrum and can be used with other ice phases.