Occurrence and fate of five representative neonicotinoid insecticides across different wastewater treatment plants and the impact on receiving water bodies.

Neonicotinoids (NEOs), despite their widespread use as insecticides, exhibit a notable knowledge deficit in regards to their presence in wastewater treatment plants (WWTPs) and their surrounding environments. This study delves into the presence and disposition of 5 NEOs: Thiamethoxam (THM), Clothianidin (CLO), Imidacloprid (IMD), Acetamiprid (ACE), and Thiacloprid (THA) across 3 domestic WWTPs and their receiving waters. Notably, THM, CLO, and ACE were consistently detected in all water and sludge samples, with THM emerging as the most abundant compound in both influent and effluent. Among the 3 WWTPs, WWTP 2, employing a fine bubble oxidation process, achieved the highest removal efficiency, surpassing 68%, in contrast to WWTP 1 (CAST) at 37% and WWTP 3 (A/A/O) at 7%. Biodegradation played a pivotal role in NEO removal, accounting for 36.7% and 68.2% of the total removal in WWTP 1 and WWTP 2, respectively. Surprisingly, in WWTP 3, biotransformation process inadvertently increased ACE and CLO concentrations by approximately 4.1% and 4.5%, respectively. The total NEO concentration in the receiving surface waters ranged from 72.7 to 155.5 ng/L, while sediment concentrations were significantly lower, spanning between 0.10 and 1.53 ng/g. WWTPs serve as both a removal and concentration point for NEOs, thereby significantly influencing their transportation. Additionally, the concentration of most NEOs in the receiving waters progressively increased from upstream to downstream, highlighting the substantial impact of WWTP discharges on natural water environments. This research offers valuable insights into NEO pollution surrounding WWTPs in the Pearl River Delta, ultimately aiding in pollution control and environmental protection decisions.

Burkholderia cenocepacia integrates cis-2-dodecenoic acid and cyclic dimeric guanosine monophosphate signals to control virulence.

Quorum sensing (QS) signals are used by bacteria to regulate biological functions in response to cell population densities. Cyclic diguanosine monophosphate (c-di-GMP) regulates cell functions in response to diverse environmental chemical and physical signals that bacteria perceive. In Burkholderia cenocepacia, the QS signal receptor RpfR degrades intracellular c-di-GMP when it senses the QS signal cis-2-dodecenoic acid, also called Burkholderia diffusible signal factor (BDSF), as a proxy for high cell density. However, it was unclear how this resulted in control of BDSF-regulated phenotypes. Here, we found that RpfR forms a complex with a regulator named GtrR (BCAL1536) to enhance its binding to target gene promoters under circumstances where the BDSF signal binds to RpfR to stimulate its c-di-GMP phosphodiesterase activity. In the absence of BDSF, c-di-GMP binds to the RpfR-GtrR complex and inhibits its ability to control gene expression. Mutations in rpfR and gtrR had overlapping effects on both the B. cenocepacia transcriptome and BDSF-regulated phenotypes, including motility, biofilm formation, and virulence. These results show that RpfR is a QS signal receptor that also functions as a c-di-GMP sensor. This protein thus allows B. cenocepacia to integrate information about its physical and chemical surroundings as well as its population density to control diverse biological functions including virulence. This type of QS system appears to be widely distributed in beta and gamma proteobacteria.

A novel two-component system modulates quorum sensing and pathogenicity in Burkholderia cenocepacia.

Quorum sensing (QS) is widely utilized by bacterial pathogens to regulate biological functions and pathogenicity. Recent evidence has shown that QS is subject to regulatory cascades, especially two-component systems that often respond to environmental stimulation. At least two different types of QS systems regulate pathogenesis in Burkholderia cenocepacia. However, it remains unclear how this bacterial pathogen controls these QS systems. Here, we demonstrate a novel two-component system RqpSR (Regulating Quorum sensing and Pathogenicity), which plays an important role in modulating QS and pathogenesis in B. cenocepacia. We demonstrate strong protein-protein binding affinity between RqpS and RqpR. Mutations in rqpS and rqpR exerted overlapping effects on B. cenocepacia transcriptomes and phenotypes, including motility, biofilm formation and virulence. In trans expression of rqpR rescued the defective phenotypes in the rqpS mutant. RqpR controls target gene expression by direct binding to DNA promoters, including the cis-2-dodecenoic acid (BDSF) and N-acylhomoserine lactone (AHL) signal synthase gene promoters. These findings suggest that the RqpSR system strongly modulates physiology by forming a complicated hierarchy with QS systems. This type of two-component system appears to be widely distributed and coexists with the BDSF QS system in various bacterial species.

Identification of Cyclic Dipeptides from Escherichia coli as New Antimicrobial Agents against Ralstonia Solanacearum.

Ralstonia solanacearum is a causative agent of bacterial wilt in many important crops throughout the world. How to control bacterial wilt caused by R. solanacearum is a major problem in agriculture. In this study, we aim to isolate the biocontrol agents that have high efficacy in the control of bacterial wilt. Three new bacterial strains with high antimicrobial activity against R. solanacearum GMI1000 were isolated and identified. Our results demonstrated that these bacteria could remarkably inhibit the disease index of host plant infected by R. solanacearum. It was indicated that strain GZ-34 (CCTCC No. M 2016353) showed an excellent protective effect to tomato under greenhouse conditions. Strain GZ-34 was characterized as Escherichia coli based on morphology, biochemistry, and 16S rRNA analysis. We identified that the main antimicrobial compounds produced by E. coli GZ-34 were cyclo(l-Pro-d-Ile) and cyclo(l-Pro-l-Phe) using electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) analysis. The two active compounds also interfered with the expression levels of some pathogenicity-contributors of R. solanacearum. Furthermore, cyclo(l-Pro-l-Phe) effectively inhibited spore formation of Magnaporthe grisea, which is a vital pathogenesis process of the fungal pathogen, suggesting cyclic dipeptides from E. coli are promising potential antimicrobial agents with broad-spectrum activity to kill pathogens or interfere with their pathogenesis.

[Non-alkaloid Chemical Constituents from Macleaya cordata].

Objective: To study the non-alkaloid chemical constituents of Macleaya cordata. Methods: Alcohol extraction and liquidliquid partitionmethods were used to extract the chemical constituents. Silica gel,reverse-phase octadecylsilyl( ODS), and Sephadex LH-20 column chromatographic methods were applied for isolation and purification. Spectroscopic methods including MS and NMR were used to determine their structures. Results: Eleven non-alkaloid compounds were isolated from the fruits of Macleaya cordata, and their structures were identified as 3-( 3,4-dihydroxy) phenylpropanoic acid methyl ester( 1),ferulic acid( 2),1-octacosanol( 3),syringic acid( 4),p-hydroxy-benzoic acid( 5),p-coumaric acid( 6),quercetin-3-O-ß-D-glucoside( 7),N-p-coumaroyl tyramine( 8),10-eicosenoic acid( 9) and ß-sitosterol( 10) and daucosterol( 11). Conclusion: Compounds 1,3 ~9 are isolated from Macleaya cordata for the first time.

The Influence of Tourist Attraction Type on Product Price Perception and Neural Mechanism in Tourism Consumption: An ERP Study.

Background: Tourism consumption is a topic with heated debates in tourism research, and pricing tourism products is a crucial task for tourism managers. Different types of tourist attractions offer different experiences to tourists, which affect their price perceptions and purchase decisions. Methods: This study combined questionnaires and event-related potentials (ERPs) measures to explore the magnitude of psychological conflict and the degree of emotional arousal that consumers experience when faced with different prices of goods in different scenic types. Results: The questionnaire results showed that attraction type influenced consumers' price perceptions and that consumers were willing to pay higher prices for products in attractions. The ERP results implied that in the early stage of cognition, attraction type did not affect consumers' perceptual processing, while price information attracted consumers' cognitive attention. In the late stage of cognition, attraction type, and price information jointly influenced consumers' decision-making, and consumers tended to accept high prices of products in entertainment attractions and cultural attractions, but consumers were more sensitive to the price of products in cultural attractions and less tolerant to price increases. Conclusion: The study elucidated how price information influenced consumers' purchase decisions of tourism products at different stages of the dual-process theory, which can assist tourism managers in devising different pricing strategies and positioning strategies based on the attributes of attractions, to enhance product sales and revenues. This would further the vision of the World Tourism Organization (UNWTO) of "tourism fostering economic development".

Association between 15 known or potential breast cancer susceptibility genes and breast cancer risks in Chinese women.

OBJECTIVE: There are many hereditary breast cancer patients in China, and multigene panel testing has been a new paradigm of genetic testing for these patients and their relatives. However, the magnitude of breast cancer risks related to multiple breast cancer susceptibility genes are largely unknown in Chinese women. METHODS: We screened pathogenic variants in 15 established or potential breast cancer susceptibility genes from 8,067 consecutive Chinese female breast cancer patients and 13,129 Chinese cancer-free female controls. These breast cancer patients were unselected for age at diagnosis or family history. RESULTS: We found that pathogenic variants in TP53 [odds ratio (OR): 16.9, 95% confidence interval (CI): 5.2-55.2]; BRCA2 (OR: 10.4, 95% CI: 7.6-14.2); BRCA1 (OR: 9.7, 95% CI: 6.3-14.8); and PALB2 (OR: 5.2, 95% CI: 3.0-8.8) were associated with a high risk of breast cancer. ATM, BARD1, CHEK2, and RAD51D were associated with a moderate risk of breast cancer with ORs ranging from 2-fold to 4-fold. In contrast, pathogenic variants of NBN, RAD50, BRIP1, and RAD51C were not associated with increased risk of breast cancer in Chinese women. The pathogenic variants of PTEN, CDH1, and STK11 were very rare, so they had a limited contribution to Chinese breast cancer. Patients with pathogenic variants of TP53, BRCA1, BRCA2, and PALB2 more often had early-onset breast cancer, bilateral breast cancer, and a family history of breast cancer and/or any cancer. CONCLUSIONS: This study provided breast cancer risk assessment data for multiple genes in Chinese women, which is useful for genetic testing and clinical management of Chinese hereditary breast cancer.

(1-aryloxy-2-hydroxypropyl)-phenylpiperazine derivatives suppress Candida albicans virulence by interfering with morphological transition.

Clinical treatment of Candida albicans infections has become more difficult due to the limited development of antifungal agents and the rapid emergence of drug resistance. In this study, we demonstrate the synthesis of a series of piperazine derivatives and the evaluation of their inhibitory activity against C. albicans virulence. Thirty-four (1-aryloxy-2-hydroxypropyl)-phenylpiperazine derivatives, including 25 new compounds, were synthesized and assessed for their efficacy against the physiology and pathogenesis of C. albicans. Several compounds strongly inhibited the morphological transition and virulence of C. albicans cells, although they did not influence the growth rate of the fungal pathogen. A leading novel compound, (1-(4-ethoxyphenyl)-4-(1-biphenylol-2-hydroxypropyl)-piperazine), significantly attenuated C. albicans virulence by interfering with the process of hyphal development, but it showed no cytotoxicity against human cells at a micromolar level. These findings suggest that (1-aryloxy-2-hydroxypropyl)-phenylpiperazine derivatives could potentially be developed as novel therapeutic agents for the clinical treatment of C. albicans infections by interfering with morphological transition and virulence.

Modulation of Inter-kingdom Communication by PhcBSR Quorum Sensing System in Ralstonia solanacearum Phylotype I Strain GMI1000.

Ralstonia solanacearum is a ubiquitous soil-borne plant pathogenic bacterium, which frequently encounters and interacts with other soil cohabitants in competition for environmental niches. Ralsolamycin, which is encoded by the rmy genes, has been characterized as a novel inter-kingdom interaction signal that induces chlamydospore development in fungi. In this study, we provide the first genetic evidence that the rmy gene expression is controlled by the PhcBSR quorum sensing (QS) system in strain GMI1000. Mutation of phcB could lead to significant reduction of the expression levels of the genes involved in ralsolamycin biosynthesis. In addition, both the phcB and rmy mutants were attenuated in induction of chlamydospore formation in Fusarium oxysporum f. cubense and diminished in the ability to compete with the sugarcane pathogen Sporisorium scitamineum. Agreeable with the pattern of QS regulation, transcriptional expression analysis showed that the transcripts of the rmy genes were increased along with the increment of the bacterial population density. Taken together, the above findings provide new insights into the regulatory mechanisms that the QS system involves in governing the ralsolamycin inter-kingdom signaling system.

Kitamycin C, a new antimycin-type antibiotic from Streptomyces antibioticus strain 200-09.

An actinomycete strain 200-09, isolated from a soil sample collected from the coast of Hawaii, USA, was identified as Streptomyces antibioticus on the basis of its morphological, physiological and biochemical characteristics as well as 16S rDNA analysis. A new antimycin-type antibiotic, kitamycin C (1), together with kitamycin A (2), kitamycin B (3), urauchmycin B (4), deisovaleryblastomycin (5) was isolated from a cultured broth of strain 200-09. The structure of the new compound was determined by spectroscopic data, including HR-ESI-MS and NMR. All the compounds exhibited antifungal activities against Candida albicans with MIC of about 25.0 µg mL-1.

Secondary metabolites from marine-derived Streptomyces antibioticus strain H74-21.

A new secondary metabolite, (2S,3R)-l-threonine, N-[3-(formylamino)-2-hydroxybenzoyl]-ethyl ester (streptomyceamide C, 1), together with four known compounds 1, 4-dimethyl-3-isopropyl-2,5-piperidinedione (2), cyclo-((S)-Pro-8- hydroxy-(R)-Ile (3), cyclo-((S)-Pro-(R)-Leu (4), and seco-((S)-Pro-(R)-Val) (5), were isolated from the EtOH extract of the fermented mycelium of the marine-derived streptomycete strain H74-21, which was isolated from sea sediment in a mangrove site. The structure of the new compound was established on the basis of its spectroscopic data, including 1D and 2D NMR, HR-TOF-MS. Their antifungal activities against Candida albicans and cytotoxicities against human breast adenocarcinoma cell line MCF-7, human glioblastoma cell line SF-268 and human lung cancer cell line NCI-H460 were tested. Compounds 1 only displayed cytotoxicity against human breast adenocarcinoma cell line MCF-7 with the IC50 value of 27.0 µg/mL. However, compounds 1-5 do not show antifungal activities at the test concentration of 1 mg/mL, and 2-5 have no cytotoxicities at the test concentration of 50 µg/mL.

Two new quercetin glycoside derivatives from the fruits of Gardenia jasminoides var. radicans.

Two new quercetin glycoside derivatives named quercetin-3-O-[2-O-trans-caffeoyl-α-L-rhamnopyranosyl-(1 → 6)-ß-D-glucopyranoside] (1) and quercetin-3-O-[2-O-trans-caffeoyl-ß-L-rhamnopyranosyl-(1 → 6)-ß-D-glucopyranoside] (2) along with three known flavonoids, 5-hydroxy-6,7,3',4',5'-pentamethoxyflavone (3), 5,7-dihydroxy-8-methoxyflavone (4) and kaempferol 3-O-ß-D-glucopyranoside (5), were isolated from the fruits of Gardenia jasminoides var. radicans. The structures of the new compounds were determined by means of extensive spectroscopic analysis (1D, 2D NMR and HR-ESI-MS), glycoside hydrolysis and sugar HPLC analysis after derivatisation. This is the first report on the isolation of a pair of compounds with α or ß-L-rhamnopyranosyl configuration from plant and the first detail assignment of their NMR data.