Short pathways to highly active antimicrobial: structurally diverse polyamines derivatives from Amino-Aldehyde condensation strategy

BACKGROUND

Chemical fungicides are the mainstay of plant disease control in agricultural production, but there are a very limited number of drugs that can effectively control plant diseases. Two series of secondary amine derivatives were synthesized using the diamine skeleton combined with saturated aromatic and aliphatic aldehydes, and their antibacterial and antifungal activities against plant pathogens were determined. In addition, the antimicrobial mechanism of the highly active compound A26 was preliminarily examined against Xanthomonas oryzae (Xoo).

RESULTS

Compound A26 exhibited the highest antibacterial potency among all the target compounds, with MIC values of 3.12, 3.12 and 12.5 μg mL-1 against Xoo, Xanthomonas axonopodis pv. Citri and Pseudomonas sollamacearum, respectively. In addition, compound A26 had powerful curative and protective effects against Xoo at 200 μg mL-1 , and was better than the control agent Xinjunan. Preliminary mechanistic studies showed that compound A26 reduced the bacterial pathogenicity by targeting cell membranes and inhibiting the secretion of extracellular polysaccharides. Meanwhile, the toxicity of compound A26 to Human Embryonic Kidney 293 cells and Human Liver-7702 was similar to that of Xinjunan, and it had moderate toxicity according to the World Health Organization classification standard of oral exogenous toxicity, with an LD50 of 245.47 mg kg-1 .

CONCLUSION

Secondary amines have efficient and broad-spectrum antibacterial activity against plant pathogenic bacteria and are expected to be a new class of candidate compounds for antibacterial drugs. © 2023 Society of Chemical Industry.

Prevalence and related factors of abdominal obesity among urban adults aged 35 to 79 years in southwest China

Objectives

This study aimed to investigate the prevalence and related factors of abdominal obesity among urban adults aged 35 to 79 years in southwest China.

Methods

From September 2013 to March 2014, a multi-stage sampling was conducted, and a total of 10,981 people aged 35-79 years living in Chengdu and Chongqing were included. More than 30 investigators were trained in data collection, including questionnaire, anthropometric measurements and blood biomarkers testing. Abdominal obesity was defined as waist circumference ≥ 90 cm for men and ≥ 85 cm for women.

Results

The prevalence of abdominal obesity was 30.7%, 24.8% in males and 33.9% in females (p < 0.001). The prevalence of abdominal obesity increased with BMI. The prevalence of abdominal obesity was positively correlated with age, sex, marriage, alcohol consumption, hypertension and diabetes, and negatively correlated with high education level, smoking and Physical activity.

Conclusion

The prevalence of abdominal obesity among adults aged 35-79 in urban communities in southwest China is high, which is close to that of adults in urban communities in China. We should strengthen health education among the population, adopt healthy diet, maintain moderate physical activity and other measures to curb the prevalence of abdominal obesity in urban communities in southwest China.

Efficacy of pterostilbene suppression on Aspergillus flavus growth, aflatoxin B1 biosynthesis and potential mechanisms

Aspergillus flavus, a widespread saprotrophic filamentous fungus, could colonize agricultural crops with aflatoxin contamination, which endangers food security and the agricultural economy. A safe, effective and environmentally friendly fungicide is urgently needed. Pterostilbene, a natural phytoalexin originated from Pterocarpus indicus Willd., Vaccinium spp. and Vitis vinifera L., has been reported to possess excellent antimicrobial activity. More importantly, it is quite safe and healthy. In our screening tests of plant polyphenols for the inhibition of A. flavus, we found that pterostilbene evidently inhibited mycelial growth of Aspergillus flavus (EC50 = 15.94 μg/mL) and the inhibitory effect was better than that of natamycin (EC50 = 22.01 μg/mL), which is a natural product widely used in food preservation. Therefore, we provided insights into the efficacy of pterostilbene suppression on A. flavus growth, aflatoxin B1 biosynthesis and its potential mechanisms against A. flavus in the present study. Here, pterostilbene at concentrations of 250 and 500 μg/mL could effectively inhibit the infection of A. flavus on peanuts. And the biosynthesis of the secondary metabolite aflatoxin B1 was also inhibited. The antifungal effects of pterostilbene are exerted by inducing a large amount of intracellular reactive oxygen species production to bring the cells into a state of oxidative stress, damaging cellular biomolecules such as DNA, proteins and lipids and destroying the integrity of the cell membrane. Taken together, our study strongly supported the fact that pterostilbene could be considered a safe and effective antifungal agent against A. flavus infection.

Exploring boron applications in modern agriculture: Antifungal activities and mechanisms of phenylboronic acid derivatives

BACKGROUND

The unreasonable use of chemical fungicides causes common adverse consequences that not only affect the environment, but also cause resistance and resurgence problems of plant pathogens, which are extremely harmful to human health, the economy, and the environment. Based on the rich biological activities of boron-based compounds, 82 phenylboronic acid derivatives were selected and their antifungal activities against six agricultural plant pathogens were determined. Combined with transcriptomics tools, the mechanism of action of compound A49 (2-chloro-5-trifluoromethoxybenzeneboronic acid) against Botrytis cinerea Pers (B. cinerea) was studied.

RESULTS

The EC₅₀ values of compounds A24, A25, A30, A31, A36, A41, A49 and B23 against all six fungi were under 10 μg/mL. Compound A49 displayed significant activity against B. cinerea (EC₅₀  = 0.39 μg/mL), which was better than that of commercial fungicide boscalid (EC₅₀  = 0.55 μg/mL). A49 not only inhibited the germination of B. cinerea spores, but also caused abnormal cell morphology, loss of cell membrane integrity, enhanced cell membrane permeability, and accumulation of intracellular reactive oxygen species. Further findings showed that A49 reduced cellular antioxidant activity, and peroxidase and catalase activities. Transcriptomic results indicated that A49 could degrade intracellular redox processes and alter the metabolism of some amino acids. Meanwhile, A49 showed obvious activity in vivo and low cytotoxicity to mammal cells.

CONCLUSION

The boron-containing small molecule compounds had high efficiency and broad-spectrum antifungal activities against six plant pathogens, and are expected to be candidate compounds for a new class of antifungal drugs. © 2023 Society of Chemical Industry.

Tavaborole-Induced Inhibition of the Aminoacyl-tRNA Biosynthesis Pathway against Botrytis cinerea Contributes to Disease Control and Fruit Quality Preservation

The inhibitory effect of tavaborole on the invasion of Botrytis cinerea in grapes and tomatoes, as well as the potential mechanism involved, was discovered in this study. Our findings showed that tavaborole inhibited Botrytis cinerea spore germination and mycelial expansion in vitro and that the control efficiency in vivo on fruit decay was dose-dependent, which was effective in reducing disease severity and maintaining the organoleptic quality of the fruit, such as reducing weight loss and retaining fruit hardness and titratable acid contents during storage. Furthermore, the precise mechanism of action was investigated further. Propidium iodide staining revealed that Botrytis cinerea treated with tavaborole lost membrane integrity. For further validation, cytoplasmic malondialdehyde accumulation and leakage of cytoplasmic constituents were determined. Notably, the inhibitory effect was also dependent on inhibiting the activities of aminoacyl-tRNA synthetases involved in the aminoacyl-tRNA biosynthesis pathway in Botrytis cinerea. The above findings concluded that tavaborole was effective against Botrytis cinerea infection in postharvest fruit, and a related mechanism was also discussed, which may provide references for the drug repurposing of tavaborole as a postharvest fungicide.

Allicin-Inspired Heterocyclic Disulfides as Novel Antimicrobial Agents

In this work, a series of derivatives with disulfide bonds containing pyridine, pyrimidine, thiophene, thiazole, benzothiazole, and quinoline were designed and synthesized based on the various biological activities of allicin disulfide bond functional groups. The antimicrobial activities of the target compounds were determined, and the structure-activity relationships were discussed. Among them, compound S8 demonstrated the most potent antifungal activity in vitro against Monilinia fructicola (M. fructicola), with an EC₅₀ value of 5.92 μg/mL. Furthermore, an in vivo bioassay revealed that compound S8 exhibited equivalent curative and higher protective effects as the positive drug thiophanate methyl at a concentration of 200 μg/mL. The preliminary mechanism experiments showed that compound S8 could inhibit the growth of M. fructicola' s hyphae in a time- and concentration-dependent manner, and compound S8 could induce the shrinkage of hyphae, disrupt the integrity of the plasma membrane, and cause the damage and leakage of cell contents. More than that, compound S5 also demonstrated an excellent antibacterial effect on Xanthomonas oryzae (X. oryzae), with a MIC₉₀ value of 1.56 μg/mL, which was superior to the positive control, thiodiazole copper.

Selenylation to charge transfer improvement at the counter electrode (CE)/electrolyte interface for nanocrystalline Cu1.8S1-xSex CEs

Pt counter electrodes (CEs) have been widely used in dye-sensitized solar cells (DSSCs) due to their high conductivity and electrocatalytic activity. However, industrialization of DSSCs is limited by shortcomings of Pt CEs such as being expensive, and weak corrosion resistance in electrolytes. Reported in this paper is two simple approaches to Pt-free Cu_1.8S_1-xSe_x CEs. Nanocrystalline Cu_1.8S_1-xSe_x CEs were fabricated via two processes, that is, a solvothermal process to Cu_1.8S_1-xSe_x powder followed by CE fabrication, and a solvothermal process and CE fabrication to Cu_1.8S films followed by selenylation to Cu_1.8S_1-xSe_x CEs. Photoelectric conversion efficiencies (PCE) of 4.02% and 4.16% were achieved respectively by the as-fabricated Cu_1.8S_1-xSe_x CEs. Compared with the cells with Cu_1.8S CEs fabricated by the same processes, increases of 19% and 45% were achieved, respectively. The PCE improvement comes from the enhancement of charge transfer at the CE/electrolyte interface induced by the selenylation of the CEs.

Design, Synthesis, and Structure-Activity Relationship Studies of Magnolol Derivatives as Antifungal Agents

Plant pathogenic fungi seriously affect agricultural production and are difficult to control. The discovery of new leads based on natural products is an important way to innovate fungicides. In this study, 30 natural-product-based magnolol derivatives were synthesized and characterized on the basis of NMR and mass spectroscopy. Bioactivity tests on phytopathogenic fungi (Rhizoctonia solani, Fusarium graminearum, Botrytis cinerea, and Sclerotinia sclerotiorum) in vitro of these compounds were performed systematically. The results showed that 11 compounds were active against four kinds of phytopathogenic fungi with EC₅₀ values in the range of 1.40-20.00 μg/mL, especially compound L5 that exhibited excellent antifungal properties against B. cinerea with an EC₅₀ value of 2.86 μg/mL, approximately 2.8-fold more potent than magnolol (EC₅₀ = 8.13 μg/mL). Moreover, compound L6 showed the highest antifungal activity against F. graminearum and Rhophitulus solani with EC₅₀ values of 4.39 and 1.40 μg/mL, respectively, and compound L7 showed good antifungal activity against S. sclerotiorum. Then, an in vivo experiment of compound L5 against B. cinerea was further investigated in vivo using infected tomatoes (curative effect, 50/200 and 36%/100 μg/mL). The physiological and biochemical studies illustrated that the primary action mechanism of compound L5 on B. cinerea might change the mycelium morphology, increase cell membrane permeability, and destroy the function of mitochondria. Furthermore, structure-activity relationship (SAR) studies revealed that hydroxyl groups play a key role in antifungal activity. To sum up, this study provides a reference for understanding the application of magnolol-based antifungal agents in crop protection.

Antifungal Activity and Action Mechanism Study of Coumarins from Cnidium monnieri Fruit and Structurally Related Compounds

The increasing resistance of plant diseases caused by phytopathogenic fungi highlights the need for highly effective and environmentally benign agents. The antifungal activities of Cnidium monnieri fruit extracts and five isolated compounds as well as structurally related coumarins against five plant pathogenic fungi were evaluated. The acetone extract, which contained the highest amount of five coumarins, showed strongest antifungal activity. Among the coumarin compounds, we found that 4-methoxycoumarin exhibited stronger and broader antifungal activity against five phytopathogenic fungi, and was more potent than osthol. Especially, it could significantly inhibit the growth of Rhizoctonia solani mycelium with an EC₅₀ value of 21 μg mL^-1 . Further studies showed that 4-methoxycoumarin affected the structure and function of peroxisomes, inhibited the β-oxidation of fatty acids, decreased the production of ATP and acetyl coenzyme A, and then accumulated ROS by damaging MMP and the mitochondrial function to cause the cell death of R. solani mycelia. 4-Methoxycoumarin presented antifungal efficacy in a concentration- dependent manner in vivo and could be used to prevent the potato black scurf. This study laid the foundation for the future development of 4-methoxycournamin as an alternative and friendly biofungicide.

The Antifungal Mechanism of Isoxanthohumol from Humulus lupulus Linn

Humulus lupulus Linn. is a traditional medicinal and edible plant with several biological properties. The aims of this work were: (1) to evaluate the in vitro antifungal activity of H. lupulus ethanolic extract; (2) to study the in vitro and in vivo antifungal activity of isoxanthohumol, an isoprene flavonoid from H. lupulus, against Botrytis cinerea; and (3) to explore the antifungal mechanism of isoxanthohumol on B. cinerea. The present data revealed that the ethanolic extract of H. lupulus exhibited moderate antifungal activity against the five tested phytopathogenic fungi in vitro, and isoxanthohumol showed highly significant antifungal activity against B. cinerea, with an EC₅₀ value of 4.32 µg/mL. Meanwhile, it exhibited moderate to excellent protective and curative efficacies in vivo. The results of morphologic observation, RNA-seq, and physiological indicators revealed that the antifungal mechanism of isoxanthohumol is mainly related to metabolism; it affected the carbohydrate metabolic process, destroyed the tricarboxylic acid (TCA) cycle, and hindered the generation of ATP by inhibiting respiration. Further studies indicated that isoxanthohumol caused membrane lipid peroxidation, thus accelerating the death of B. cinerea. This study demonstrates that isoxanthohumol can be used as a potential botanical fungicide for the management of phytopathogenic fungi.

P–522 Cervical secretion methylation profile is associated with the success of frozen-thawed embryo transfer - a proof-of-concept study

Study question

Is cervical secretion gene methylation profile different between receptive and non-receptive endometrium and associated with implantation outcome in frozen-embryo transfer (FET) cycle?

Summary answer

The combination of candidate genes methylation profiles obtained from cervical secretion showed significant associations with pregnancy outcomes.

What is known already

Implantation failure remains a black box in reproductive medicine, and the exact mechanism of how endometrial receptivity is regulated is still unknown. Epigenetic modifications play a role in the gene expression pattern and may alter the endometrial receptivity in the human endometrium. Cervical secretion containing various implantation-related cytokines, and the gene methylation change can be used as a non-invasive molecular source that reflects the endometrium condition.

Study design, size, duration

In this retrospective case-control study, sixty-two women who entered the FET cycle (30 pregnant and 32 non-pregnant women) were enrolled.

Participants/materials, setting, methods

Cervical secretion was collected before embryo transfer from women enrolled in multicenter university-affiliated reproductive units. The DNA methylation status of six candidate genes was measured using quantitative methylation-specific PCR (qMSP). The correlation between methylation change and the pregnancy outcome was analyzed.

Main results and the role of chance

The candidate genes were selected from that associated with implantation with literature review and the original genome-wide DNA methylation data from NCBI GEO DataSets (GSE90060) which processed using bioinformatics analysis. Six candidate genes whose CpG-level methylation analysis with β-value statistically higher in receptive endometrium than in a pre-receptive endometrium were selected. All six candidate genes showed different degrees of correlation with the pregnancy outcomes. Among them, PRKAG2 methylation changes showed the highest correlation with the pregnancy outcome. A logistic regression model was used to evaluate the performance of a single gene or a combination of genes for implantation prediction. The results showed a statistically significant association between the methylation status of a combination of genes (PRKAG2, KRS1, HAND2) and the pregnancy outcome (p = 0.008), resulting in an optimal AUC of 0.7 (95% CI: 0.57 - 0.81) for implantation prediction.

Limitations, reasons for caution

The results obtained from a relatively small cohort size. A larger study and further comprehensive methylome investigations are warranted.

Wider implications of the findings: This study is the first proof-of-concept study that cervical secretion methylation profile is associated with implantation outcome in a FET cycle, and showed potential as a non-invasive method for implantation prediction.

Trial registration number

non applicable

Isolation and Characterization of Nocardia Species from Pulmonary Nocardiosis in a tertiary hospital in China

The aim of this study was to investigate the clinical features, distribution and antimicrobial susceptibility of Nocardia species isolated from pulmonary nocardiosis cases in tertiary hospital in China. The species were collected from January 1, 2018 to May 31, 2019 and identified using MALDI-TOF MS or PCR. Antimicrobial susceptibility testing was performed using the broth microdilution method. Within the 44 Nocardia species, N. farcinica was the most frequently identified species (n = 36), followed by N. nova (n = 5), N. otitidiscaviarum (n = 1), N. cyriacigeorgica (n = 1), and N. transvalensis (n = 1). The top three predisposing factors of pulmonary nocardiosis were chronic obstructive pulmonary disease (45.5%), hypertension (34.1%), and tuberculosis (31.8%). All 44 Nocardia strains were susceptible to amikacin, trimethoprim / sulfamethoxazole, and linezolid. The resistance rates of Nocardia to amoxicillin-clavulanic acid, ciprofloxacin, clarithromycin, ceftriaxone, tobramycin, and imipenem were 4.5%, 9.1%, 79.5%, 72.7%, 63.6%, and 38.6%, respectively. Two Nocardia strains had decreased sensitivity to trimethoprim / sulfamethoxazole. In conclusion, N. farcinica was the most frequently isolated Nocardia species in the First Hospital of Changsha. All isolated clinical Nocardia strains showed susceptible to amikacin, trimethoprim / sulfamethoxazole, and linezolid, suggesting that these drugs can be primary therapeutic choices for treating Nocardia infections.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

[Clinical application of mCIM and eCIM combined detection of carbapenemase-producing enterobacteriaceae]

Objective: To explore the clinical application value of modified carbapenem inactivation test (mCIM) combined with EDTA-modified carbapenem inactivation test (eCIM) for detecting the carbapenemase of CRE isolated from infected patients in clinical diagnosis and infection control of CRE infection. Methods: Drug resistance of seventy eight non-repetitive enterobacteriaceae resistant to carbapenem antibiotics, which were isolated from clinically infected patients from January 2017 to December 2017 in the Tianjin Medical University General Hospital, was retrospectively analyzed. Meanwhile, Vitek2 Compact automatic bacterial identification instrument was used to identify the species and detect its minimum inhibitory concentration (MIC) for ertapenem and imipenem. Carbapenemase genes bla_KPC, bla_NDM, bla_IMP and bla_VIM were detected by PCR test, the genotype was determined by gene sequencing as the gold standard, and mCIM Combined eCIM test was used for carbapenemase detection of collected bacteria. Using PCR results as the standard, the sensitivity, specificity, positive predictive value, negative predictive value and Cohen' Kappa value of mCIM and eCIM were calculated, and the consistency of the combined detection results of mCIM and eCIM and PCR results was checked. Results: Seventy eight carbapenem-resistant Enterobacteriaceae were detected by PCR, 74 carbapenemase gene positive and 4 negative, including 60 bla_KPC-2 positive, 2 bla_NDM-1 positive and bla_NDM-5 positive Of the 7 strains, 3 strains were positive for bla_NDM-9, 1 strain was positive for bla_IMP-4, and 1 strain was both positive for bla_KPC-2 and bla_NDM-1. The sensitivity of mCIM to detect carbapenemase is 100%, the specificity is 100%, and the Kappa value is 1.000; the combined detection of mCIM and eCIM for serine carbapenemase has a sensitivity of 100%, the specificity is 100%, and the Kappa value is 1.000; The sensitivity of combined detection of metallo-β-lactamase is 92.9%, the specificity is 100%, and the Kappa value is 0.955. Conclusions: The combined test of mCIM and eCIM which is used to detect carbapenemase in CRE costs low, doesn't require special reagents and equipment, has strong practicability, simple operation, and easy interpretation of results. According to the different genotypes of CRE bacteria, it provides important clinical diagnostic evidence for clinical CRE diagnosis, precise antimicrobial treatment and infection control.

Characterization of carbapenem-resistant hypervirulent Acinetobacter baumannii strains isolated from hospitalized patients in the mid-south region of China

Background

Acinetobacter baumannii has traditionally been considered an opportunistic pathogen with low virulence. In this study, we characterized the carbapenem-resistant hypervirulent A. baumannii (CR-hvAB) stains isolated from our hospital in mid-south region of China.

Results

Blood samples collected between January 2017 and May 2019 were used for virulence experiments and biofilm assays of individual carbapenem-resistant A. baumannii (CR-AB) strains, performed using a Galleria mellonella infection model and crystal violet staining method, respectively. CR-AB isolates that induced high mortality in the G. mellonella infection model were subjected to genotyping, susceptibility testing, and clinical data analysis, and the genetic characterization of these isolates was performed by whole-genome sequencing (WGS). Among the 109 CR-AB clinical strains, the survival rate of G. mellonella larvae infected with 7 (6.4%) CR-AB isolates (number of strains with mortality of 0, 10 and 20% was 4, 1, and 2, respectively), was significantly lower than that of A. baumannii ATCC 19606 (100.0%) and the remaining CR-AB isolates (> 80.0%). Consistent with these results, patients infected with these seven isolates had an average 7-day mortality rate of 42.9%, suggesting that the isolates were CR-hvAB. These seven isolates belonged to four sequence types (STs): ST457, ST195, ST369, and ST2088 (a new ST), and mainly ST457 (n = 4). The results of the biofilm study showed that eight strains had powerful biofilm ability (strong [n = 1] and moderate [n = 7] biofilm producers) including these seven CR-hvAB isolates.

Conclusions

CR-hvAB isolates that induced a high mortality rate were cloned in our hospital, most of which belonged to ST457; thus, monitoring of these strains, particularly ST457, should be strengthened in the future. Meanwhile, A. baumannii, which was isolated from blood specimens and found to powerful biofilm-forming ability, is a probable hvAB isolate.

Emergence of an NDM-5-Producing Escherichia coli Sequence Type 410 Clone in Infants in a Children's Hospital in China

Purpose

Outbreaks of infection due to carbapenem-resistant Enterobacterales (CRE), including New Delhi metallo-β-lactamase (NDM)-producing Escherichia coli, have been increasingly reported worldwide, primarily in adults and rarely in children. The goal of this study was to characterize an outbreak of infection caused by NDM-5-producing E. coli in a children’s hospital in China.

Methods

A total of 86 CRE isolates were collected from 85 hospitalized children between June 2017 and May 2018. These isolates were subjected to multiple phenotypic and molecular tests, including in vitro antimicrobial susceptibility testing, PCR, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), and whole-genome sequencing (WGS).

Results

Among the 86 CRE isolates, we identified 9 NDM-5-producing E. coli isolates, with 5 of them sharing the same PFGE pattern, same MLST type (ST410), same plasmid replicon type (IncFII), and nearly the same set of additional resistance genes. All 9 isolates were resistant to most antimicrobial agents, including carbapenems, cephalosporins, and levofloxacin, while being sensitive to trimethoprim/sulfamethoxazole, amikacin, tigecycline, and colistin. According to the clinical background, all 9 isolates were collected in a period of < 3 months from infants among whom there was overlap in the time of hospitalization. None of them had a travel history.

Conclusion

Our analysis suggests an outbreak of clonal dissemination, presumably due to nosocomial transmission. This study represents the first documented outbreak of NDM-5-producing E. coli mediated by IncFII in infants. Close monitoring is urgently needed to prevent and control the spread of this difficult-to-treat superbug.

[Therapy-related myeloid neoplasms after successful treatment for acute promyelocytic leukemia: a report of four cases and literature review]

目的

探讨急性早幼粒细胞白血病（APL）患者继发治疗相关性髓系肿瘤（t-MN）的临床特点、诊断、治疗及预后。

方法

回顾性分析中国医学科学院血液病医院2012年10月至2019年1月收治的4例APL继发t-MN患者的临床资料，并进行相关文献复习。

结果

4例APL继发t-MN患者均为女性，中位年龄42（40~53）岁，3例接受了以维甲酸（ATRA）+亚砷酸（ATO）为基础联合蒽环/蒽醌类药物±阿糖胞苷的前期诱导缓解及巩固治疗方案，1例采用了ATRA联合蒽环/蒽醌类药物±阿糖胞苷的治疗方案，均没有使用烷化剂。在APL获得完全缓解（CR）后40~43个月出现t-MN，其中治疗相关性骨髓增生异常综合征（t-MDS）1例，治疗相关性急性髓系白血病（t-AML）3例，出现t-MN时PML-RARα融合基因均为阴性。3例t-AML患者接受了2~4个疗程再诱导治疗，其中有1例t-AML患者在获得CR后行异基因造血干细胞移植（allo-HSCT），1例t-MDS患者接受了去甲基化治疗。中位随访54.5（48~62）个月，2例t-AML患者死亡，出现t-MN后中位生存期为12（5~18）个月。1989至2018年文献共报道63例APL继发t-MN病例，与本次报道的4例汇总分析，67例患者中男27例，女40例；中位年龄为52.5（15~76）岁；中位潜伏期39（12~168）个月，确诊t-MN后中位生存时间为10（1~39）个月。

结论

APL继发t-MN较为少见，目前缺乏有效的防治措施，预后不佳，在随访过程中（尤其是获得CR后39个月左右）若出现病情变化，应警惕t-MN的发生，对此类患者应尽快明确疾病的变化，给予合理的治疗。

[Investigation on the content of persistent organic pollutants in fish from Dongting Lake in China]

Objective: To investigate the content of persistent organic pollutants (POPs) in fish from Dongting Lake. Methods: Ten sample collection points were set in lakeside city Yueyang and Yuanjiang. In July (wet season) and November (dry season) of 2012, 13 common fish species were captured by convenience sampling in Dongting Lake. Two to three fish with similar weight were selected in each season for the same species of fish. After sample preparation and pretreatment, the contents of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (dl-PCBs), indicator polychlorinated biphenyls and polybrominated diphenyls ether (PBDEs) in the samples were determined by high resolution gas chromatographer-high resolution mass spectrometry. Toxicity Equivalents (TEQ) of PCDD/Fs and dl-PCBs were calculated according to the revised toxicity equivalent factor (TEF) of WHO in 2005. The contents of POPs were expressed by median and quavtile. The differences of POPs in fish in different periods were compared by Wilcoxon rank sum test. Results: The content of PCDD/Fs of fish in Dongting Lake in wet season was 12.397 (8.865, 24.964) pg/g, higher than that in the dry season 0.771 (0.490, 1.442) pg/g (P<0.001), and the toxicity equivalent quantity (TEQ) were 0.150 (0.066,0.528) and 0.143 (0.066, 0.235) pg-TEQ/g without statistically significant difference (P>0.05). For the fish in wet and dry season from Dongting Lake,Σdl-PCBs of fish were 66.475 (28.065, 77.794) and 24.205 (18.237, 90.777) pg/g, respectively, and the TEQ were 0.061 (0.046, 0.268) and 0.075 (0.054, 0.182) pg-TEQ/g; Σ indicative PCBs were 237.764 (153.896, 335.483) and 119.711 (52.171, 408.696) pg/g, respectively; Σ PBDEs were 106.513 (64.834, 164.860) and 86.837 (61.872, 177.108) pg/g, respectively. The highest content of PCDD/Fs was found in grass carp (198.360 pg/g) in wet season. The higher content of PCBs was found in long-necked fish (2 332.509 pg/g) and PBDEs was found in pelteobagrus fulvidraco (343.857 pg/g), respectively. Conclusion: A lower burden was found in fishes from Dongting Lake, and the content of POPs varied in different seasons and fishes.

Isolation and characterization of a sequence type 25 carbapenem-resistant hypervirulent Klebsiella pneumoniae from the mid-south region of China

Background

The molecular characterization of carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) isolates is not well studied. Our goal was to investigate the molecular epidemiology of CR-hvKP strains that were isolated from a Chinese hospital.

Results

All clinical carbapenem-resistant K. pneumoniae (CR-KP) isolates were collected and identified from patient samples between 2014 and 2017 from a Chinese hospital. The samples were subjected to screening for CR-hvKP by string test and the detection of the aerobactin gene. CR-hvKP isolates were further confirmed through neutrophil phagocytosis and a mice lethality assay. The CR-hvKP isolates were investigated for their capsular genotyping, virulence gene profiles, and the expression of carbapenemase genes by PCR and DNA sequencing. Multilocus sequence type (MLST) and pulsed-field gel electrophoresis (PFGE) were performed to exclude the homology of these isolates. Twenty strains were identified as CR-hvKP. These strains were resistant to imipenem and several other antibiotics, however, most were susceptible to amikacin. Notably, two isolates were not susceptible to tigecycline. Capsular polysaccharide synthesis genotyping revealed that 17 of the 20 CR-hvKP strains belonged to the K2 serotype, while the others belonged to serotypes other than K1, K2, K5, K20, and K57. The strains were found to be positive for 10 types of virulence genes and a variety of these genes coexisted in the same strain. Two carbapenemase genes were identified: bla_KPC-2 (13/20) and bla_NDM-1 (1/20). PFGE typing revealed eight clusters comprising isolates that belonged to MLST types ST25, ST11 and ST375, respectively. PFGE cluster A was identified as the main cluster, which included 11 isolates that belong to ST25 and mainly from ICU department.

Conclusions

Our findings suggest that hospital-acquired infections may contribute in part to the CR-hvKP strains identified in this study. It also suggests that ST25 CR-hvKP strain has a clonal distribution in our hospital. Therefore, effective surveillance and strict infection control strategies should be implemented to prevent outbreak by CR-hvKP strains in hospitals setting.

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω_{0}^{T}<5.58×10^{-8}, Ω_{0}^{V}<6.35×10^{-8}, and Ω_{0}^{S}<1.08×10^{-7} at a reference frequency f_{0}=25  Hz.

GW170817: Implications for the Stochastic Gravitational-Wave Background from Compact Binary Coalescences

The LIGO Scientific and Virgo Collaborations have announced the event GW170817, the first detection of gravitational waves from the coalescence of two neutron stars. The merger rate of binary neutron stars estimated from this event suggests that distant, unresolvable binary neutron stars create a significant astrophysical stochastic gravitational-wave background. The binary neutron star component will add to the contribution from binary black holes, increasing the amplitude of the total astrophysical background relative to previous expectations. In the Advanced LIGO-Virgo frequency band most sensitive to stochastic backgrounds (near 25 Hz), we predict a total astrophysical background with amplitude Ω_{GW}(f=25  Hz)=1.8_{-1.3}^{+2.7}×10^{-9} with 90% confidence, compared with Ω_{GW}(f=25  Hz)=1.1_{-0.7}^{+1.2}×10^{-9} from binary black holes alone. Assuming the most probable rate for compact binary mergers, we find that the total background may be detectable with a signal-to-noise-ratio of 3 after 40 months of total observation time, based on the expected timeline for Advanced LIGO and Virgo to reach their design sensitivity.

[Operative strategy and clinical results of complex four part distal radius fractures by combined palmar and dorsal internal fixation]

Objective: To explore a standard procedure for the treatment of combined dorsal and palmar internal fixation for complex four part distal radius fractures and assess its clinical results. Methods: From May 2009 to October 2016, 38 patients(39 sides)who suffered from complex four part distal radius fractures were performed operatively with open reduction and internal fixation via combined dorsal and palmar approach in Department of Orthopaedic Trauma, Qilu Hospital of Shandong University(Qingdao). The series included 22 males(22 sides) and 16 females(17 sides). Age of the patients was 53.5 years ranging from 25 to 79 years.According to Melone classification, there were 34 sides of type of Ⅳ, 5 of type Ⅴ.According to Frykman classification, there were 15 sides of type Ⅶ, 24 sides of type Ⅷ, and all the cases were type C3 according to AO/OTA classification.Preoperatively, the key articular fragments in four part distal radius fractures were identified and the individual fracture patterns from conventional X-ray and CT-scan were analyzed. All the patients were performed combined volar and dorsal fixation.Firstly, a palmar approach which gave access to and fix the palmar-ulnar fragment and the radial styloid fragment was performed.Then a limited dorsal approach across the third extensor compartment which gave access to the dorso-ulnar fragment and a limited dorsal arthrotomy to visualize the radiocarpal joint when necessary were performed.Through dorsal approach, we can address the dorso-ulnar fragment, free intra-articular fragment and direct visualize the joint.Use of a retinacular flap was routinely advocated to help prevent against tendon irritation and rupture.The follow-up control included conventional X-ray, range of motion(ROM), grip strength, and the disabilities of the arm, shoulder and hand index(DASH), as well as the patient-rated wrist evaluation(PRWE) score for functional outcome at 6 and 12 months. Results: Thirty-three patients(34 sides) were followed up for at least 12 months.The would healed well in all cases 2 weeks postoperatively, and no soft tissue infections, necrosis or neurovascular complications occurred.All the fractures of 38 cases(39 sides)healed averaged 3.6 months(ranging from 2.5-5.7 months), and no loss of reduction occurred postoperatively.Anatomic reconstruction with a step or gap of <1 mm was achieved in 37 cases(38 sides), Whereas 5 patients were lost to follow-up at 12 months postoperatively.ROM and grip strength were all recovered to over 85% of the unaffected side(exception of the bilateral patient). Median DASH-index and PRWE were 6.5(0-17) and 9.3(0-20)respectively. Conclusion: Combined volar and dorsal approaches allow achieving anatomic reconstruction in complex four part intra-articular distal radius fractures and reveal good functional outcomes at intermediate follow-up.

First Search for Nontensorial Gravitational Waves from Known Pulsars

We present results from the first directed search for nontensorial gravitational waves. While general relativity allows for tensorial (plus and cross) modes only, a generic metric theory may, in principle, predict waves with up to six different polarizations. This analysis is sensitive to continuous signals of scalar, vector, or tensor polarizations, and does not rely on any specific theory of gravity. After searching data from the first observation run of the advanced LIGO detectors for signals at twice the rotational frequency of 200 known pulsars, we find no evidence of gravitational waves of any polarization. We report the first upper limits for scalar and vector strains, finding values comparable in magnitude to previously published limits for tensor strain. Our results may be translated into constraints on specific alternative theories of gravity.

GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral

On August 17, 2017 at 12∶41:04 UTC the Advanced LIGO and Advanced Virgo gravitational-wave detectors made their first observation of a binary neutron star inspiral. The signal, GW170817, was detected with a combined signal-to-noise ratio of 32.4 and a false-alarm-rate estimate of less than one per 8.0×10^{4}  years. We infer the component masses of the binary to be between 0.86 and 2.26  M_{⊙}, in agreement with masses of known neutron stars. Restricting the component spins to the range inferred in binary neutron stars, we find the component masses to be in the range 1.17-1.60  M_{⊙}, with the total mass of the system 2.74_{-0.01}^{+0.04}M_{⊙}. The source was localized within a sky region of 28  deg^{2} (90% probability) and had a luminosity distance of 40_{-14}^{+8}  Mpc, the closest and most precisely localized gravitational-wave signal yet. The association with the γ-ray burst GRB 170817A, detected by Fermi-GBM 1.7 s after the coalescence, corroborates the hypothesis of a neutron star merger and provides the first direct evidence of a link between these mergers and short γ-ray bursts. Subsequent identification of transient counterparts across the electromagnetic spectrum in the same location further supports the interpretation of this event as a neutron star merger. This unprecedented joint gravitational and electromagnetic observation provides insight into astrophysics, dense matter, gravitation, and cosmology.

GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Upper Limits on the Stochastic Gravitational-Wave Background from Advanced LIGO's First Observing Run

A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves to be Ω_{0}<1.7×10^{-7} with 95% confidence, assuming a flat energy density spectrum in the most sensitive part of the LIGO band (20-86 Hz). This is a factor of ∼33 times more sensitive than previous measurements. We also constrain arbitrary power-law spectra. Finally, we investigate the implications of this search for the background of binary black holes using an astrophysical model for the background.

Directional Limits on Persistent Gravitational Waves from Advanced LIGO's First Observing Run

We employ gravitational-wave radiometry to map the stochastic gravitational wave background expected from a variety of contributing mechanisms and test the assumption of isotropy using data from the Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. We also search for persistent gravitational waves from point sources with only minimal assumptions over the 20-1726 Hz frequency band. Finding no evidence of gravitational waves from either point sources or a stochastic background, we set limits at 90% confidence. For broadband point sources, we report upper limits on the gravitational wave energy flux per unit frequency in the range F_{α,Θ}(f)<(0.1-56)×10^{-8}    erg cm^{-2} s^{-1} Hz^{-1}(f/25  Hz)^{α-1} depending on the sky location Θ and the spectral power index α. For extended sources, we report upper limits on the fractional gravitational wave energy density required to close the Universe of Ω(f,Θ)<(0.39-7.6)×10^{-8}  sr^{-1}(f/25  Hz)^{α} depending on Θ and α. Directed searches for narrowband gravitational waves from astrophysically interesting objects (Scorpius X-1, Supernova 1987 A, and the Galactic Center) yield median frequency-dependent limits on strain amplitude of h_{0}<(6.7,5.5,  and  7.0)×10^{-25}, respectively, at the most sensitive detector frequencies between 130-175 Hz. This represents a mean improvement of a factor of 2 across the band compared to previous searches of this kind for these sky locations, considering the different quantities of strain constrained in each case.

An Outbreak of Infections Caused by a Klebsiella pneumoniae ST11 Clone Coproducing Klebsiella pneumoniae Carbapenemase-2 and RmtB in a Chinese Teaching Hospital

Background:

Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae bacteria, which cause serious disease outbreaks worldwide, was rarely detected in Xiangya Hospital, prior to an outbreak that occurred from August 4, 2014, to March 17, 2015. The aim of this study was to analyze the epidemiology and molecular characteristics of the K. pneumoniae strains isolated during the outbreak.

Methods:

Nonduplicate carbapenem-resistant K. pneumoniae isolates were screened for bla_KPC-2 and multiple other resistance determinants using polymerase chain reaction. Subsequent studies included pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, analysis of plasmids, and genetic organization of bla_KPC-2 locus.

Results:

Seventeen bla_KPC-2-positive K. pneumoniae were identified. A wide range of resistant determinants was detected. Most isolates (88.2%) coharbored bla_KPC-2 and rmtB in addition to other resistance genes, including bla_SHV-1, bla_TEM-1, and aac(3)-IIa. The bla_KPC-2 and rmtB genes were located on the conjugative IncFIB-type plasmid. Genetic organization of bla_KPC-2 locusin most strains was consistent with that of the plasmid pKP048. Four types (A1, A2, A3, and B) were detected by PFGE, and Type A1, an ST11, was the predominant PFGE type. A novel K. pneumoniae sequence type (ST1883) related to ST11 was discovered.

Conclusions:

These isolates in our study appeared to be clonal and ST11 K. pneumoniae was the predominant clone attributed to the outbreak. Coharbing of bla_KPC-2 and rmtB, which were located on a transferable plasmid, in clinical K. pneumoniae isolates may lead to the emergence of a new pattern of drug resistance.

Characterization of transient noise in Advanced LIGO relevant to gravitational wave signal GW150914

On September 14, 2015, a gravitational wave signal from a coalescing black hole binary system was observed by the Advanced LIGO detectors. This paper describes the transient noise backgrounds used to determine the significance of the event (designated GW150914) and presents the results of investigations into potential correlated or uncorrelated sources of transient noise in the detectors around the time of the event. The detectors were operating nominally at the time of GW150914. We have ruled out environmental influences and non-Gaussian instrument noise at either LIGO detector as the cause of the observed gravitational wave signal.

GW151226: Observation of Gravitational Waves from a 22-Solar-Mass Binary Black Hole Coalescence

We report the observation of a gravitational-wave signal produced by the coalescence of two stellar-mass black holes. The signal, GW151226, was observed by the twin detectors of the Laser Interferometer Gravitational-Wave Observatory (LIGO) on December 26, 2015 at 03:38:53 UTC. The signal was initially identified within 70 s by an online matched-filter search targeting binary coalescences. Subsequent off-line analyses recovered GW151226 with a network signal-to-noise ratio of 13 and a significance greater than 5σ. The signal persisted in the LIGO frequency band for approximately 1 s, increasing in frequency and amplitude over about 55 cycles from 35 to 450 Hz, and reached a peak gravitational strain of 3.4_{-0.9}^{+0.7}×10^{-22}. The inferred source-frame initial black hole masses are 14.2_{-3.7}^{+8.3}M_{⊙} and 7.5_{-2.3}^{+2.3}M_{⊙}, and the final black hole mass is 20.8_{-1.7}^{+6.1}M_{⊙}. We find that at least one of the component black holes has spin greater than 0.2. This source is located at a luminosity distance of 440_{-190}^{+180}  Mpc corresponding to a redshift of 0.09_{-0.04}^{+0.03}. All uncertainties define a 90% credible interval. This second gravitational-wave observation provides improved constraints on stellar populations and on deviations from general relativity.

Properties of the Binary Black Hole Merger GW150914

On September 14, 2015, the Laser Interferometer Gravitational-Wave Observatory (LIGO) detected a gravitational-wave transient (GW150914); we characterize the properties of the source and its parameters. The data around the time of the event were analyzed coherently across the LIGO network using a suite of accurate waveform models that describe gravitational waves from a compact binary system in general relativity. GW150914 was produced by a nearly equal mass binary black hole of masses 36_{-4}^{+5}M_{⊙} and 29_{-4}^{+4}M_{⊙}; for each parameter we report the median value and the range of the 90% credible interval. The dimensionless spin magnitude of the more massive black hole is bound to be <0.7 (at 90% probability). The luminosity distance to the source is 410_{-180}^{+160}  Mpc, corresponding to a redshift 0.09_{-0.04}^{+0.03} assuming standard cosmology. The source location is constrained to an annulus section of 610  deg^{2}, primarily in the southern hemisphere. The binary merges into a black hole of mass 62_{-4}^{+4}M_{⊙} and spin 0.67_{-0.07}^{+0.05}. This black hole is significantly more massive than any other inferred from electromagnetic observations in the stellar-mass regime.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

GW150914: First results from the search for binary black hole coalescence with Advanced LIGO

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) simultaneously observed the binary black hole merger GW150914. We report the results of a matched-filter search using relativistic models of compact-object binaries that recovered GW150914 as the most significant event during the coincident observations between the two LIGO detectors from September 12 to October 20, 2015. GW150914 was observed with a matched filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203000 years, equivalent to a significance greater than 5.1 σ.

Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

[Effect of 5-HT7 receptor agonist on pyramidal neurons in the medial frontal cortex in a rat model of Parkinson's disease]

OBJECTIVE

To investigate the activity of pyramidal neurons in the medial prefrontal cortex (mPFC) of normal and 6-OHDA-lesioned rats and the responses of the neurons to 5-hydroxytryptamine-7 (5-HT(7)) receptor stimulation.

METHODS

The changes in spontaneous firing of the pyramidal neurons in the mPFC in response to 5-HT(7) receptor stimulation were observed by extracellular recording in normal and 6-OHDA-lesioned rats.

RESULTS

Both systemic and local administration of 5-HT(7) receptor agonist AS 19 resulted in 3 response patterns (excitation, inhibition and no change) of the pyramidal neurons in the mPFC of normal and 6-OHDA-lesioned rats. In normal rats, the predominant response of the pyramidal neurons to AS 19 stimulation was excitatory, and the inhibitory effect of systemically administered AS 19 was reversed by GABAA receptor antagonist picrotoxinin. In the lesioned rats, systemic administration of AS 19 also increased the mean firing rate of the pyramidal neurons, but the cumulative dose for producing excitation was higher than that in normal rats. Systemic administration of AS 19 produced an inhibitory effect in the lesioned rats, which was partially reversed by picrotoxinin. Local administration of AS 19 at the same dose did not change the ?ring rate of the neurons in the lesioned rats.

CONCLUSION

The activity of mPFC pyramidal neurons is directly or indirectly regulated by 5-HT7 receptor, and degeneration of the nigrostriatal pathway leads to decreased response of these neurons to AS 19.

GW150914: Implications for the Stochastic Gravitational-Wave Background from Binary Black Holes

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M_{⊙}, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), we predict Ω_{GW}(f=25  Hz)=1.1_{-0.9}^{+2.7}×10^{-9} with 90% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO and Advanced Virgo detectors operating at their projected final sensitivity.

GW150914: The Advanced LIGO Detectors in the Era of First Discoveries

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10^{-23}/sqrt[Hz] at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here, we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of 3 improvement in the signal-to-noise ratio for binary black hole systems similar in mass to GW150914.

Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Minimally invasive manipulative reduction with poking k-wire fixation in the treatment of various types of calcaneal fractures

OBJECTIVE

The aim of this study is to investigate the safety and clinical efficacy of minimally invasive manipulative reduction with poking k-wire fixation in the treatment of various types of calcaneal fractures.

PATIENTS AND METHODS

Between July 2012 and July 2014, a prospective parallel controlled study was conducted on 96 patients with closed calcaneal fractures who were admitted to our institution. These patients were randomly divided into two groups, with 48 in each group. Patients in plate group were treated using open reduction and internal fixation, whereas those of manipulation group were treated with minimally invasive manipulative reduction with poking k-wire fixation. All patients were followed up for six months to assess the postoperative recovery and complications. Kerr's scale was adopted to evaluate the functional recovery of fractured calcaneus.

RESULTS

A mean healing duration of 9.48 ± 1.92 weeks was achieved in patients of plate group compared with a healing duration of 9.35 ± 1.66 weeks in those of manipulation group, with no statistical significance (p > 0.05). Complications occurred in 20 cases in plate group versus in seven cases in manipulation group with significant difference (p < 0.05). As for Sanders type II fracture, among patients with compression fracture and tongue type fracture, > 70% of patients achieved with excellent and good outcomes in both groups with no significant difference in clinical efficacy (p > 0.05). The rate of excellent and good outcomes in Sanders type III compression fractures was lower in manipulation group than in plate group (p < 0.05). As for Sanders type II fractures, the Kerr's score of tongue type fractures in manipulation group was higher than that in plate group, and comparison within manipulation group showed that the score of tongue type fractures was significantly higher than that of compression fractures (p < 0.05). However, as for Sanders type III fractures, the score of tongue type fractures in manipulation group was significantly higher than that in plate group, and the score of compression fractures in plate group was significantly higher than that in manipulation group (p < 0.05).

CONCLUSIONS

Minimally invasive manipulative reduction with poking k-wire fixation is suitable for the treatment of Sanders type II tongue type and compression calcaneal fractures, as well as the treatment of Sanders type III tongue type fractures with several advantages, including easy operation, lower cost, fewer complications and favorable recovery.

[Effect of sodium nitrite on phosphorylation of cytoskeletal proteins and spatial learning and memory in rats]

The present study was aimed to explore the effect of sodium nitrite on cytoskeletal protein phosphorylation and spatial learning and memory in rats. Rats were served with drinking water containing sodium nitrite (100 mg/kg) for 60 days, then, the ability of spatial learning and memory of the rats was measured by Morris water maze. Phosphorylation level of tau and neurofilament, and the expression of protein phosphatase 2A (PP2A) catalytic subunit in the hippocampus were detected by immunohistochemistry and Western blot. In comparison with the rats served with normal tap water, the rats served with sodium nitrite water showed significantly longer latency to find the hidden platform in Morris water maze (P < 0.05), elevated phosphorylation level of tau and neurofilament, and decreased expression of PP2A catalytic subunit (P < 0.05). These results indicated that administration of sodium nitrite could impair the spatial learning and memory of the rats, and the hyperphosphorylation of cytoskeletal proteins and the down-regulation of PP2A might be underlying mechanisms for the impairment.

Adrenomedullin and adrenotensin regulate collagen synthesis and proliferation in pulmonary arterial smooth muscle cells

To understand the pathophysiological mechanisms of pulmonary arterial smooth muscle cell (PASMC) proliferation and extracellular-matrix accumulation in the development of pulmonary hypertension and remodeling, this study determined the effects of different doses of adrenomedullin (ADM) and adrenotensin (ADT) on PASMC proliferation and collagen synthesis. The objective was to investigate whether extracellular signal-regulated kinase (ERK1/2) signaling was involved in ADM- and ADT-stimulated proliferation of PASMCs in 4-week-old male Wistar rats (body weight: 100-150 g, n=10). The proliferation of PASMCs was examined by 5-bromo-2-deoxyuridine incorporation. A cell growth curve was generated by the Cell Counting Kit-8 method. Expression of collagen I, collagen III, and phosphorylated ERK1/2 (p-ERK1/2) was evaluated by immunofluorescence. The effects of different concentrations of ADM and ADT on collagen I, collagen III, and p-ERK1/2 protein expression were determined by immunoblotting. We also investigated the effect of PD98059 inhibition on the expression of p-ERK1/2 protein by immunoblotting. ADM dose-dependently decreased cell proliferation, whereas ADT dose-dependently increased it; and ADM and ADT inhibited each other with respect to their effects on the proliferation of PASMCs. Consistent with these results, the expression of collagen I, collagen III, and p-ERK1/2 in rat PASMCs decreased after exposure to ADM but was upregulated after exposure to ADT. PD98059 significantly inhibited the downregulation by ADM and the upregulation by ADT of p-ERK1/2 expression. We conclude that ADM inhibited, and ADT stimulated, ERK1/2 signaling in rat PASMCs to regulate cell proliferation and collagen expression.

A novel human TINP1 gene promotes cell proliferation through inhibition of p53 and p21 expression

Transforming growth factor (TGF)-β-inducible nuclear protein 1 (TINP1) is a novel gene, which is localized at chromosome 5q13 where frequent abnormalities in hairy cell leukemia (HCL) occur. The present study investigated the effects of TINP1 knockdown or overexpression on the viability and gene expression of various tumor cell lines. siTINP1 was designed to knock down TINP1 expression. Reverse transcription polymerase chain reaction (RT-PCR) and western blotting were performed to assess gene expression; the cell counting kit-8 (CCK-8) assay was used to detect cell viability, and luciferase and flow cytometry assays were used to determine gene activity. TINP1 was widely expressed in various cell lines. In addition, TINP1 siRNA was able to knock down TINP1 expression in HeLa cells. TINP1 overexpression significantly promoted tumor cell proliferation, which may be associated with the downregulation of p53 expression. Furthermore, TINP1 promoted a number of cell lines to the S phase of the cell cycle. TINP1 promotes cell proliferation and significantly reduces p53 and p21 expression.

Primary lymphoepithelioma-like carcinoma of ocular adnexa: clinicopathologic features and treatment

BACKGROUND AND METHODS

Lymphoepithelioma-like carcinoma (lelc) is a rare malignancy in ocular adnexa. Here, we report 4 patients with lelc and review 11 patients reported in the literature. Clinical profiles, association with Epstein-Barr virus (ebv), treatment, and outcomes are analyzed.

RESULTS

Lacrimal glands and the lacrimal drainage system, eyelid, and conjunctiva are potential primary sites for lelc. The tumours are characterized histologically by nests of undifferentiated malignant cells surrounded by lymphoid infiltrates. Infection with ebv was confirmed in lelc of ocular adnexa, and that association seemed to be restricted to Asian populations. Results from our centre uniformly showed expression of ebv-encoded small rnas in primary tumour, locally recurrent tumour, and metastatic lymph nodes. This disease had a tendency to relapse regionally. Postoperative radiotherapy seems to improve disease-free survival. Tumours appear to be sensitive to radiotherapy and chemotherapy based on cisplatin and 5-fluorouracil. At our centre, 3 patients were still living at 22, 33, and 76 months after surgery. One patient died of distant metastasis after a survival of 38 months.

CONCLUSIONS

Lymphoepithelioma-like carcinoma is a heterogenous entity among ocular adnexal malignancies. Multimodality treatment provides a better chance at survival. Further investigation is required to achieve a better understanding of the biologic behavior of this entity and of its optimal treatment.

Molecular analysis and frequency of Staphylococcus aureus virulence genes isolated from bloodstream infections in a teaching hospital in Tianjin, China

Staphylococcus aureus is an important cause of bloodstream infections worldwide. We examined the prevalence of genes that encode erythromycin ribosome methylase and bacterial toxins in S. aureus collected from bloodstream infections. Sixty different S. aureus isolates were obtained from blood cultures of patients who were admitted to a Teaching Hospital in Tianjin from January 2006 to August 2011. The susceptibility of the isolates to 16 antibiotics was tested. Methicillin-resistant S. aureus (MRSA) was identified using the disk diffusion method with cefoxitin. PCR was used to detect genes that encode the staphylococcal enterotoxins, Panton-Valentine leukocidin, toxic shock syndrome toxin 1 and erythromycin ribosome methylase. Molecular analysis of the MRSA strains was done using pulsed-field gel electrophoresis (PFGE) and staphylococcal cassette chromosome mec (SCCmec) typing. The positivity rates of mecA, ermA, ermB, and ermC in the isolates were 13/60, 10/60, 18/60, and 18/60, respectively. Among the 60 isolates, 30 harbored enterotoxin genes, with sea as the most frequent toxin gene (33%), followed by sec (15%), sed (12%), and seb (5%). The see and tst genes were not found in any of the isolates. The pvl gene was detected in four strains. Eleven MRSA isolates were of the SCCmec type III; two MRSA isolates could not be determined through SCCmec typing. PFGE analysis of the 13 MRSA isolates produced 8 distinct pulsotypes. Virulence genes and erythromycin ribosome methylase genes were highly prevalent in these isolates. The PFGE results demonstrated that the MRSA spread through cloning, mainly involving SCCmec type III.

Lipidomics identification of metabolic biomarkers in chemically induced hypertriglyceridemic mice

In this study, we aim to identify the potential biomarkers in hTG pathogenesis in schisandrin B-induced hTG mouse model. To investigate whether these identified biomarkers are only specific to schisandrin B-induced hTG mouse model, we also measured these biomarkers in a high fat diet (HFD)-induced hTG mouse model. We employed a LC/MS/MS-based lipidomic approach for the study. Mouse liver and serum metabolites were separated by reversed phase liquid chromatography. Metabolite candidates were identified by matching with marker retention times, isotope distribution patterns, and high-resolution MS/MS fragmentation patterns. Subsequently, target candidates were quantified by quantitative MS. In the schisandrin B-induced hTG mice, we found that the plasma fatty acids, diglyceroids, and phospholipids were significantly increased. Palmitic acid and stearic acid were increased in the plasma; oleic acid, linoleic acid, linolenic acid, arachidonic acid, and docosahexaenoic acid were increased in both the plasma and the liver. Acetyl-CoA, malonyl-CoA, and succinyl-CoA were increased only in the liver. The changes in levels of these identified markers were also observed in HFD-induced hTG mouse model. The consistent results obtained from both hTG models not only suggest novel biomarkers in hTG pathogenesis, but they also provide insight into the underlying mechanism of the schisandrin B-induced hTG.

Effects of Erxian decoction, a Chinese medicinal formulation, on serum lipid profile in a rat model of menopause

BACKGROUND

The prevalence and risk of cardiovascular disease increase after menopause in correlation with the progression of abnormality in the serum lipid profile and the deprivation of estrogen. Erxian decoction (EXD), a Chinese medicinal formulation for treating menopausal syndrome, stimulates ovarian estrogen biosynthesis. This study investigates whether EXD improves the serum lipid profile in a menopausal rat model.

METHODS

Twenty-month-old female Sprague Dawley rats were treated with EXD and its constituent fractions. Premarin was administered for comparison. After eight weeks of treatment, rats were sacrificed and the serum levels of total cholesterol, triglyceride, high-density-lipoprotein cholesterol and low-density-lipoprotein cholesterol were determined. The hepatic protein levels of 3-hydroxy-3-methyl-glutaryl-CoA reductase and low-density-lipoprotein receptor were assessed with Western blot.

RESULTS

The serum levels of total cholesterol and low-density-lipoprotein cholesterol were significantly lower in the EXD-treated group than in the constituent fractions of EXD or premarin groups. However, the serum levels of triglyceride and high-density-lipoprotein cholesterol were not significantly different from the control groups. Results from Western blot suggest that EXD significantly down-regulated the protein level of 3-hydroxy-3-methyl-glutaryl-CoA reductase and up-regulated low-density-lipoprotein receptor. Conclusion EXD improves serum lipid profile in a menopausal rat model through the suppression of the serum levels of total cholesterol and low-density-lipoprotein cholesterol, possibly through the down-regulation of the 3-hydroxy-3-methyl-glutaryl-CoA and up-regulation of the low-density-lipoprotein receptor.

Stereoselective biotransformation of timosaponin A-III by Saccharomyces cerevisiae

Bioconversion of timosaponin A-III (TA-III), one of the major steroidal saponins isolated from the rhizomes of Anemarrhenae asphodeloides Bunge (Liliaceae), was investigated in Saccharomyces cerevisiae. Five bioconversion products, denoted compounds 2-6, were obtained. Biotransformation metabolite 2 was a stereoisomer of TAIII with a specific isotype F-ring and beta-ranged CH3-21, which rarely occurs in nature. The structure of 2 was elucidated by extensive spectroscopic analysis (H-H COSY, HSQC, HMBC), as well as by high-resolution mass spectral analysis. The growth inhibitory activity of compounds 1-6 was assayed against four human cancer cell lines, HepG2, H-1299, HT-29, and HCT-116. Compounds 1 and 2 obviously inhibited the growth of the four types of cancer cells with IC50 values being less than 19 micrometer. A structure-activity relationship is discussed, and the spirostane-ring F in compounds 1 and 2 appears to be the critical bioactive moiety for the cell growth inhibitory property.