ROS regulated reversible protein phase separation synchronizes plant flowering.

How aerobic organisms exploit inevitably generated but potentially dangerous reactive oxygen species (ROS) to benefit normal life is a fundamental biological question. Locally accumulated ROS have been reported to prime stem cell differentiation. However, the underlying molecular mechanism is unclear. Here, we reveal that developmentally produced H2O2 in plant shoot apical meristem (SAM) triggers reversible protein phase separation of TERMINATING FLOWER (TMF), a transcription factor that times flowering transition in the tomato by repressing pre-maturation of SAM. Cysteine residues within TMF sense cellular redox to form disulfide bonds that concatenate multiple TMF molecules and elevate the amount of intrinsically disordered regions to drive phase separation. Oxidation triggered phase separation enables TMF to bind and sequester the promoter of a floral identity gene ANANTHA to repress its expression. The reversible transcriptional condensation via redox-regulated phase separation endows aerobic organisms with the flexibility of gene control in dealing with developmental cues.

Comparison of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio for the diagnosis of neonatal sepsis: a systematic review and meta-analysis.

PURPOSE: To compare the performance of Neutrophil-to-Lymphocyte Ratio (NLR) with that of Platelet-to-Lymphocyte Ratio (PLR) in diagnosing neonatal sepsis (NS). METHODS: PubMed and Embase were searched for relevant studies from the inception of the databases to May, 2022. The pooled sensitivity (SEN), specificity (SPE), and area under the receiver operator characteristic curve (AUC) were measured. RESULTS: Thirteen studies involving 2610 participants were included. The SEN, SPE, and AUC of NLR were 0.76 (95%CI: 0.61-0.87), 0.82 (95%CI: 0.68-0.91), and 0.86 (95%CI: 0.83-0.89), respectively, and those of PLR were 0.82 (95%CI: 0.63-0.92), 0.80 (95%CI: 0.24-0.98), and 0.87 (95%CI: 0.83-0.89), respectively. Significant heterogeneity was observed among the studies. Subgroup analysis and meta-regression showed that types of sepsis (p = 0.01 for SEN), gold standard (p = 0.03 for SPE), and pre-set threshold (p<0.05 for SPE) might be the sources of heterogeneity for NLR, whereas the pre-set threshold (p<0.05 for SPE) might be the source of heterogeneity for PLR. CONCLUSIONS: NLR and PLR would be of great accuracy for the diagnosis of NS, and the two indicators have similar diagnostic performance. However, the overall risk of bias was high, and significant heterogeneity was identified among the included studies. The results of this study should be interpreted prudently, and the normal or cut-off values and the type of sepsis should be considered. More prospective studies are needed to further support the clinical application of these findings.

Deep anterior lamellar keratoplasty with cross-linked acellular porcine corneal stroma to manage fungal keratitis.

PURPOSE: To evaluate the effects of deep anterior lamellar keratoplasty (DALK) with cross-linked acellular porcine corneal stroma (APCS) and post-operative topical tacrolimus treatment in patients with fungal keratitis. METHODS: This multicenter prospective study involved 25 cases of fungal keratitis that were treated by DALK with cross-linked APCSs and post-operative topical tacrolimus from December 2013 to November 2014 at the Wenzhou Eye Hospital and the Henan provincial Eye Hospital. Signs of post-operative inflammation, corneal reepithelialization, corneal neovascularization, and graft rejection were assessed, and best corrected visual acuity (BCVA), intraocular pressure (IOP), and APCS graft transparency were monitored for the 12-month follow-up period. RESULTS: All 25 patients underwent DALK without Descemet's membrane perforation. Corneal epithelium recovered completely in 17 patients in the first week, and APCS grafts maintained transparency in 18 patients at 1-year follow-up. The mean BCVA significantly improved from 2.16 ± 0.32 (LogMAR) at baseline to 1.56 ± 0.70 at 1-week (P < .001), 0.95 ± 0.57 at 1-month (P < .001), and 0.70 ± 0.51 at 3-month follow-ups (P < .001). The BCVA kept stable at 6-month and 12-month follow-ups. Post-operative topical tacrolimus alleviated the ciliary injection, except in one case which acute stromal rejection occurred. One patient developed fungal reinfection and underwent penetrating keratoplasty. Graft rejection occurred in three patients. No case was noted with graft splitting, elevated IOP or tacrolimus intolerance. CONCLUSIONS: DALK using cross-linked APCS combining topical tacrolimus treatment is safe and effective in managing fungal keratitis. It may ameliorate the shortage of corneal donation globally.

The effects of Micro/Nano-plastics exposure on plants and their toxic mechanisms: A review from multi-omics perspectives.

In recent years, plastic pollution has become a global environmental problem, posing a potential threat to agricultural ecosystems and human health, and may further exacerbate global food security problems. Studies have revealed that exposure to micro/nano-plastics (MPs/NPs) might cause various aspects of physiological toxicities, including plant biomass reduction, intracellular oxidative stress burst, photosynthesis inhibition, water and nutrient absorption reduction, cellular and genotoxicity, seed germination retardation, and that the effects were closely related to MP/NP properties (type, particle size, functional groups), exposure concentration, exposure duration and plant characteristics (species, tissue, growth stage). Based on a brief review of the physiological toxicity of MPs/NPs to plant growth, this paper comprehensively reviews the potential molecular mechanism of MPs/NPs on plant growth from perspectives of multi-omics, including transcriptome, metabolome, proteome and microbiome, thus to reveal the role of MPs/NPs in plant transcriptional regulation, metabolic pathway reprogramming, protein translational and post-translational modification, as well as rhizosphere microbial remodeling at multiple levels. Meanwhile, this paper also provides prospects for future research, and clarifies the future research directions and the technologies adopted.

Divergence in regulatory mechanisms of GR-RBP genes in different plants under abiotic stress.

The IVa subfamily of glycine-rich proteins (GRPs) comprises a group of glycine-rich RNA binding proteins referred to as GR-RBPa here. Previous studies have demonstrated functions of GR-RBPa proteins in regulating stress response in plants. However, the mechanisms responsible for the differential regulatory functions of GR-RBPa proteins in different plant species have not been fully elucidated. In this study, we identified and comprehensively studied a total of 34 GR-RBPa proteins from five plant species. Our analysis revealed that GR-RBPa proteins were further classified into two branches, with proteins in branch I being relatively more conserved than those in branch II. When subjected to identical stresses, these genes exhibited intensive and differential expression regulation in different plant species, corresponding to the enrichment of cis-acting regulatory elements involving in environmental and internal signaling in these genes. Unexpectedly, all GR-RBPa genes in branch I underwent intensive alternative splicing (AS) regulation, while almost all genes in branch II were only constitutively spliced, despite having more introns. This study highlights the complex and divergent regulations of a group of conserved RNA binding proteins in different plants when exposed to identical stress conditions. These species-specific regulations may have implications for stress responses and adaptations in different plant species.

S1P/S1PR signaling pathway advancements in autoimmune diseases.

Sphingosine-1-phosphate (S1P) is a versatile sphingolipid that is generated through the phosphorylation of sphingosine by sphingosine kinase (SPHK). S1P exerts its functional effects by binding to the G protein-coupled S1P receptor (S1PR). This lipid mediator plays a pivotal role in various cellular activities. The S1P/S1PR signaling pathway is implicated in the pathogenesis of immune-mediated diseases, significantly contributing to the functioning of the immune system. It plays a crucial role in diverse physiological and pathophysiological processes, including cell survival, proliferation, migration, immune cell recruitment, synthesis of inflammatory mediators, and the formation of lymphatic and blood vessels. However, the full extent of the involvement of this signaling pathway in the development of autoimmune diseases remains to be fully elucidated. Therefore, this study aims to comprehensively review recent research on the S1P/S1PR axis in diseases related to autoimmunity.

Luteolin inhibits angiogenesis and enhances radiotherapy sensitivity of laryngeal cancer via downregulating Integrin ß1.

AIM: To demonstrate the role and mechanism of luteolin in radio-sensitization and angiogenesis of laryngeal cancer. METHODS: Firstly, we analyzed the cytotoxicity of Luteolin and radiation sensitive cytotoxicity through CCK8, and selected subsequent radiation doses and Luteolin concentrations. Next, we further analyzed the effects of Luteolin on radiation sensitivity and neovascularization of laryngeal cancer, and conducted CCK8, plate cloning, and angiogenesis experiments, respectively. At the same time, the effects of individual treatment and combination treatment on the expression of Integrin ß1 and VEGFA were analyzed through immunofluorescence analysis. We also analyzed the regulation of Integrin ß1 protein expression by Luteolin through Western blot. To investigate the mechanism of Integrin ß1, we transfected overexpressed and silenced Integrin ß1 vectors and analyzed the role of Integrin ß1 in Luteolin enhancing radiation sensitivity of laryngeal cancer by repeating the above experiments. We have also constructed an in vivo subcutaneous tumor transplantation model to further validate the cell experimental results. The expression of Integrin, KI67, VEGFA, and CD31 was analyzed through Western blot and immunohistochemistry experiments. RESULTS: Radiation inhibited cell proliferation and decreased Integrin ß1 expression, and increased the radiosensitivity through inhibiting cell proliferation, and inhibit angiogenesis during radiation. Overexpression of Integrin ß1 weakened radiotherapy sensitivity on the basis of cells treated with combined administration. Integrin ß1 is considered as the downstream molecule of luteolin, participating in radiosensitivity of luteolin to FaDu cells. Animal experiments also demonstrated that luteolin strengthened tumor suppression and anti-angiogenesis during radiation via Integrin ß1. CONCLUSION: In summary, our results manifested that radio-sensitivity effect of luteolin depended on downregulating Integrin ß1 in laryngocarcinoma.

Structural characterization and transformation of nitrogen compounds in waste tire pyrolysis oils.

The waste tire pyrolysis oil (WTPO) has been widely concerned because it's a promising recycling method of waste tires. However, the high content of nitrogen in WTPO is unfavorable to its application. In this work, nitrogen compounds in the full distillation range of a waste tire pyrolysis oil were characterized by gas chromatograph-nitrogen chemiluminescence detector (GC-NCD), gas chromatograph-mass spectrometry (GC-MS) and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). In the gasoline fraction of WTPO, the most abundant nitrogen compounds were benzonitrile, aniline and small molecule nitriles. In the diesel fraction of WTPO, the most abundant nitrogen compounds were benzothiazole, quinoline derivatives, p-phthalodinitrile, benzonitrile derivatives, hexadecanenitrile and octadecanenitrile. In the heavy fraction of WTPO, significant amounts of NxOy (x = 2-3 and y = 1-2) species were discovered after the separation of solvent dissolution and solid phase extraction. The molecular structures of these NxOy species were determined as amide derivatives of diphenylamine by tandem mass spectra of FT-ICR MS. Therefore, the origin of nitriles in the light fractions of WTPO was suspected as the pyrolysis of these amides in the heavy fractions. Finally, the nitrogen transformation during the pyrolysis of waste tires was suggested based on the results of quantum chemistry simulations. These results would be helpful for the treatment and removal of these undesirable nitrogen compounds in WTPO.

[The changes of ocular bacterial isolates and in vitro antimicrobial susceptibility in the past six years].

OBJECTIVE: To analyze the changes of ocular bacterial isolates and their susceptibility to ciprofloxacin, ofloxacin, levofloxacin, gatifloxacin and tobramycin in Henan Province in the past six years. METHODS: Retrospective study of ocular bacterial isolates and their in vitro antimicrobial susceptibility test results of Henan Eye Institute in the past six years. RESULTS: A total of 2044 bacterial isolates were classified into 39 kinds in the past six years, which were mainly from the conjunctival sac. Staphylococcus epidermidis was the most common, followed by Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus cereus. All kinds of the ocular bacteria had the highest susceptibility to gatifloxacin (92.3%) among the tested drugs. Rods were more sensitive to quinolone drugs than cocci and gram-positive rods were more sensitive to tobramycin than the other types of germs. The drug's susceptibility of the four kinds of quinolone except ciprofloxacin decreased year by year with a decreasing ladder fashion every two years in the susceptibility change of levofloxacin in the past six years, while the susceptibility of tobramycin increased slowly from 2004 to 2008 and then decreased. Staphylococcus epidermidis susceptibility to every drug had the similar trend with the general changes in the past six years, that is, their susceptibility to ofloxacin decreased significantly since 2008, their susceptibility to gatifloxacin and tobramycin reduced significantly in 2009. Although Pseudomonas aeruginosa susceptibility to all the drugs had no significant change, for all gram-negative rods, their susceptibility to the four kinds of quinolone drugs were higher than their susceptibility to tobramycin while their susceptibility to levofloxacin and gatifloxacin reduced significantly as time passed by, especially from the year 2008 to 2009. CONCLUSIONS: The most common ocular bacterial isolates were Staphylococcus epidermidis, followed by Pseudomonas aeruginosa. Ocular bacterial isolates' susceptibility to gatifloxacin in vitro was significantly higher than to other drugs in every year but decreased significantly in 2009 while their susceptibility to ofloxacin and levofloxacin decreased significantly since 2008. Their susceptibility to tobramycin increased slowly from 2004 to 2008 and then decreased.

Silencing PLOD2 attenuates cancer stem cell-like characteristics and cisplatin-resistant through Integrin ß1 in laryngeal cancer.

Laryngeal cancer (LC) is an aggressive malignancy resistant to drug treatments. It has been postulated that cancer stem cells (CSCs) persist in a unique population of cancer cells involved in tumor progression and drug-resistance. In the present study, the effects of PLOD2 expression on ordinary and Cisplatin (DDP)-resistance (R) cells were investigated in TU686 and TU138 cells and Xenograft model. Cell viability, invasion and cell apoptosis, CD44 and CD133 expressions, MRP1 and P-gp expressions were measured by CCK-8 assay, Transwell, flow cytometry, immunofluorescence and Western blotting respectively. The results of our study demonstrated that suppressing the expression of PLOD2 could meditate LC stem cell-like features by decrease cell viability and invasion, increase apoptotic rate, decrease CD44 and CD133 expressions via Integrin ß1. Meanwhile, the inhibition of PLOD2 expression could decrease P-gp and MRP1expression thus markedly regulate DDP-R LC cells stemness and drug-resistance via Integrin ß1. Our findings provided a new rationale for subsequent academic and clinical research on LC drug-resistance.

Impact of the surrounding environment on antibiotic resistance genes carried by microplastics in mangroves.

The pollution of antibiotic resistance genes (ARGs) carried by microplastics (MPs) is a growing concern. Mangroves are located at the intersection of land and sea and are seriously affected by MP pollution. However, few studies have systematic research evaluating the transmission risk of ARGs carried by MPs in mangroves. We conducted in situ experiments by burying five different MPs (polypropylene, high-density polyethylene, polystyrene, polyethylene glycol terephthalate, and polycaprolactone particles) in mangroves with different surrounding environments. A total of 10 genes in the MPs of mangroves were detected using quantitative real-time polymerase chain reactions, including eight ARGs and two mobile genetic elements (MGEs). The abundance of ARGs in Guanhai park mangroves in living areas (GH) was higher than that of Gaoqiao mangroves in protected areas (GQ) and Beiyue dike mangroves in aquaculture pond areas (BY). Pathogenic bacteria, such as Acinetobacter, Bacillus, and Vibrio were found on the MP surfaces of the mangroves. The number of ARGs carried by multiple drug-resistant bacteria in the GH mangroves was greater than that in the GQ and BY mangroves. Moreover, the ARGs carried by MPs in GH mangroves had the highest potential transmission risk by horizontal gene transfer. Sociometric and environmental factors were the main drivers shaping the distribution characteristics of ARGs and MGEs. Polypropylene and high-density polyethylene particles are preferred substrates for obtaining diffuse ARGs. This study investigated the drivers of ARGs in the MPs of mangroves and provided essential guidance on the use and handling of plastics.

Heterotypic transcriptional condensates formed by prion-like paralogous proteins canalize flowering transition in tomato.

BACKGROUND: Paralogs that arise from gene duplications during genome evolution enable genetic redundancy and phenotypic robustness. Variation in the coding or regulatory sequence of paralogous transcriptional regulators diversifies their functions and relationships, which provides developmental robustness against genetic or environmental perturbation. The fate transition of plant shoot stem cells for flowering and reproductive success requires a robust transcriptional control. However, how paralogs function and interact to achieve such robustness is unknown. RESULTS: Here, we explore the genetic relationship and protein behavior of ALOG family transcriptional factors with diverse transcriptional abundance in shoot meristems. A mutant spectrum covers single and higher-order mutant combinations of five ALOG paralogs and creates a continuum of flowering transition defects, showing gradually enhanced precocious flowering, along with inflorescence simplification from wild-type-like to progressively fewer flowers until solitary flower with sterile floral organs. Therefore, these paralogs play unequal roles and act together to achieve a robust genetic canalization. All five proteins contain prion-like intrinsically disordered regions (IDRs) and undergo phase separation. Accumulated mutations following gene duplications lead to IDR variations among ALOG paralogs, resulting in divergent phase separation and transcriptional regulation capabilities. Remarkably, they retain the ancestral abilities to assemble into a heterotypic condensate that prevents precocious activation of the floral identity gene ANANTHA. CONCLUSIONS: Our study reveals a novel genetic canalization mechanism enabled by heterotypic transcriptional condensates formed by paralogous protein interactions and phase separation, uncovering the molecular link between gene duplication caused IDR variation and robust transcriptional control of stem cell fate transition.

Variety-Specific Transcriptional and Alternative Splicing Regulations Modulate Salt Tolerance in Rice from Early Stage of Stress.

Salt stress poses physiological drought, ionic toxicity and oxidative stress to plants, which causes premature senescence and death of the leaves if the stress sustained. Salt tolerance varied between different rice varieties, but how different rice varieties respond at the early stage of salt stress has been seldom studied comprehensively. By employing third generation sequencing technology, we compared gene expressional changes in leaves of three rice varieties that varied in their level of tolerance after salt stress treatment for 6 h. Commonly up-regulated genes in all rice varieties were related to water shortage response and carbon and amino acids metabolism at the early stage of salt stress, while reactive oxygen species cleavage genes were induced more in salt-tolerant rice. Unexpectedly, genes involved in chloroplast development and photosynthesis were more significantly down-regulated in the two salt tolerant rice varieties 'C34' and 'Nona Bokra'. At the same time, genes coding ribosomal protein were suppressed to a more severe extent in the salt-sensitive rice variety 'IR29'. Interestingly, not only variety-specific gene transcriptional regulation, but also variety-specific mRNA alternative splicing, on both coding and long-noncoding genes, were found at the early stage of salt stress. In summary, differential regulation in gene expression at both transcriptional and post-transcriptional levels, determine and fine-tune the observed response in level of damage in leaves of specific rice genotypes at early stage of salt stress.

Separation of false-positive microplastics and analysis of microplastics via a two-phase system combined with confocal Raman spectroscopy.

In the field of microplastics research, more accurate standardised methods and analytical techniques still need to be explored. In this study, a new method for the microplastics quantitatively and qualitatively analysis by two-phase (ethyl acetate-water) system combined with confocal Raman spectroscopy was developed. Microplastics can be separated from false-positive microplastics in beach sand and marine sediment, attributing to the hydrophobic-lipophilic interaction (HLI) of the two-phase system. Results show that the recovery rates of complex environment microplastics (polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide 66 (PA 66), polycarbonate (PC) and polyethylene (PE)) are higher than 92.98%. Moreover, the new technique can also be used to detect hydrophobic and lipophilic antibiotics, such as sulfamethoxazole (SMX), erythromycin (EM), madimycin (MD), and josamycin (JOS), which adsorbed on microplastics and are extracted based on the dissolving-precipitating mechanism. This innovative research strategy provides a new scope for further detection of marine environment microplastics and toxic compounds adsorbed on its surface.

Proline induces calcium-mediated oxidative burst and salicylic acid signaling.

Although free proline accumulation is a well-documented phenomenon in many plants in response to a variety of environmental stresses, and is proposed to play protective roles, high intracellular proline content, by either exogenous application or endogenous over-production, in the absence of stresses, is found to be inhibitory to plant growth. We have shown here that exogenous application of proline significantly induced intracellular Ca(2+) accumulation in tobacco and calcium-dependent ROS production in Arabidopsis seedlings, which subsequently enhanced salicylic acid (SA) synthesis and PR genes expression. This suggested that proline can promote a reaction similar to hypersensitive response during pathogen infection. Other amino acids, such as glutamate, but not arginine and phenylalanine, were also found to be capable of inducing PR gene expression. In addition, proline at concentration as low as 0.5 mM could induce PR gene expression. However, proline could not induce the expression of PDF1.2 gene, the marker gene for jasmonic acid signaling pathway. Furthermore, proline-induced SA production is mediated by NDR1-dependent signaling pathway, but not that mediated by PAD4. Our data provide evidences that exogenous proline, and probably some other amino acids can specifically induce SA signaling and defense response.

Geodermatophilus ruber sp. nov., isolated from rhizosphere soil of a medicinal plant.

A novel actinobacterial strain, designated CPCC 201356(T), was isolated from a rhizosphere soil sample of the medicinal plant Astragalus membranaceus and subjected to a polyphasic taxonomic analysis. Good growth occurred at 20-32 °C, at pH 7.0-7.5 and with 0-1 % (w/v) NaCl. Colonies on R2A and ISP 2 agar were light red to red, round and lacked aerial mycelium; cells adhered to the agar. The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H(4)) and MK-9. Polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and two unknown phospholipids. The major cellular fatty acids were iso-C(16 : 0), iso-C(15 : 0) and C(17 : 1)ω8c. The G+C content of the genomic DNA was 72.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain CPCC 201356(T) belonged to the family Geodermatophilaceae and consistently formed a distinct sub-branch with Geodermatophilus obscurus DSM 43160(T). The organism showed 16S rRNA gene sequence similarity of 97.7 % with G. obscurus DSM 43160(T). DNA-DNA hybridization between strain CPCC 201356(T) and G. obscurus DSM 43160(T) was 17.4 %. On the basis of evidence from this polyphasic taxonomic study, a novel species, Geodermatophilus ruber sp. nov., is proposed; the type strain is CPCC 201356(T) (=DSM 45317(T) =CCM 7619(T)).

Agromyces flavus sp. nov., an actinomycete isolated from soil.

A gram-positive, non-motile strain, designated CPCC 202695(T), was isolated from a soil sample collected from the Qinghai-Tibet plateau, north-west China. Strain CPCC 202695(T) contained rhamnose, glucose and galactose in the cell wall as diagnostic sugars and 2,4-diaminobutyric acid, alanine, glutamic acid and glycine in the peptidoglycan. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. MK-12 was the predominant menaquinone and anteiso-C(15 : 0) (34.2 %), iso-C(15 : 0) (19.8 %), iso-C(16 : 0) (12.7 %) and anteiso-C(17 : 0) (11.1 %) were the major fatty acids. 16S rRNA gene sequence similarities (94.2-97.1 %) between the isolate and the type strains of recognized species of the genus Agromyces indicated that strain CPCC 202695(T) was a member of the genus Agromyces. DNA-DNA relatedness clearly separated strain CPCC 202695(T) from its closest relatives. The phenotypic and genotypic data demonstrated that strain CPCC 202695(T) represents a novel species of the genus Agromyces, for which the name Agromyces flavus sp. nov. is proposed. The type strain is CPCC 202695(T) ( = KCTC 19578(T)  = CCM 7623(T)).

Chemotaxis-selective colonization of mangrove rhizosphere microbes on nine different microplastics.

Microplastics pollution poses a new threat to the environment of intertidal zone. The sea forest, mangrove, has been polluted by a large number of plastic debris worldwide. To fill the gaps in knowledge of mangrove rhizosphere microbes connected with the 'plasticsphere', a semi-controlled in situ exposure experiment for nine different types of microplastics were conducted in mangrove ecosystem. A sign of biodegrading was observed on polyethylene, polyamide 6 and polyvinyl chloride microplastics surface after 3 months exposure. We discovered that the metabolic activities of the dominant bacteria on certain microplastics were related to the specific groups on polymers molecule. The selective colonization may be driven by the chemotaxis of bacteria. Specially, microplastics biofilms of polyethylene, polyamide 6, polyvinyl chloride and expanded polystyrene possess distinctive dominant bacteria assemblages which have great significance in ecosystem processes involving carbon cycle or sulfur cycle. Community of mangrove soil microorganism and microplastic biofilm varies as the seasons changes. As a new niche, microplastics has higher inclusivity to bacteria than surrounding soil. Additionally, pathogens for human beings (Vibrio parahaemolyticus and Escherichia-Shigella) were detected both in microplastics and soil. We stress that the interaction between microplastics and rhizosphere microorganisms may affect the growth and health of mangrove plants. Besides, we point out that mangrove rhizosphere microorganism can be an ideal candidate for plastics-degradation.

Diversity of culturable actinobacteria from Qinghai-Tibet plateau, China.

To investigate the diversity of culturable actinobacteria and further screen for microbial pharmaceutics, seven different media were chosen to isolate actinobacteria from 87 soil samples collected from Qinghai-Tibet plateau. A total of 1930 strains was isolated and identified to belong to 11 suborders, i.e., Actinopolysporineae, Corynebacterineae, Frankineae, Glycomycineae, Kineosporiineae, Micrococcineae, Micromonosporineae, Propionibacterineae, Pseudonocardineae, Streptomycineae and Streptosporangineae, and 16 families, i.e., Nocardioidaceae, Actinopolysporaceae, Actinosynnemataceae, Dermacoccaceae, Geodermatophilaceae, Glycomycetaceae, Kineosporiaceae, Microbacteriaceae, Micromonosporaceae, Nocardiaceae, Promicromonosporaceae, Propionibacteriaceae, Pseudonocardiaceae, Streptomycetaceae, Streptosporangiaceae and Thermomonosporaceae. A primary taxonomic study showed that at least 22 genera of actinobacteria were identified from the soil samples, among which ten isolates represented hitherto unknown species. The results showed that there was abundant actinobacterial species diversity in the soil samples from the Qinghai-Tibet plateau.

[Comparative research of the efficacy of the gatifloxacin and levofloxacin for bacterial conjunctivitis in human eyes].

OBJECTIVE: To evaluate the different efficacy and safety to the treatment of bacterial conjunctivitis between the fluoroquinolone antibiotics gatifloxacin and levofloxacin. METHODS: A multi-centre, random, double-blind and control trial was performed in six centers including Eye Ear Nose and Throat Hospital of Fudan University, Henan Eye Institute, Eye Hospital Affiliated to Wenzhou Medical College, the First Affiliated Hospital Of Nanjing Medical University, Xijing Hospital Affiliated to the Fourth Military Medical University, the Second Affiliated Hospital of Xi'an Jiaotong University between August 2006 and October 2007. The levofloxacin was set as the efficient control. Two hundred and thirty-five patients (235 eyes) that diagnosed as bacterial conjunctivitis were randomly divided into two groups by the method of randomized blocks, the test group (gatifloxacin) had 118 eyes and the control (levofloxacin) group had 117 eyes. The drug delivery into conjunctival sac was performed at a 7-day period (two drops per time, eight times per day at the first two days and two drops per time, four times per day at the following 5 days). All participants were given the conjunctival sac germ culture and drug sensitive test before and after the study. The combination score of signs and symptoms and evaluation of safety were conducted at the pre-delivery day, the (4 ± 1) and (7 ± 1) delivery day. The statistic analysis was conducted by CMH χ(2) test, Pearson χ(2) test and Fisher's exact probabilities test. RESULTS: The efficacy of the two groups was 94.0% (110/117 eyes) in gatifloxacin group and 93.8% (106/113 eyes) in levofloxacin group with no significant difference (χ(2) = 0.052, P = 0.8201). There was also no difference in the bacteria clearance between the two groups [gatifloxacin versus levofloxacin, 94.1% (80/85 eyes) versus 92.5% (74/80 eyes), P = 0.3470]. The decrease of combination score of signs and symptoms at the (4 ± 1) delivery day was 4.436 ± 2.310 in the gatifloxacin group and 3.814 ± 1.962 in the levofloxacin group, the difference of which was significant (F = 7.280, P = 0.0075). This trend was also proved at the (7 ± 1) delivery day (gatifloxacin versus levofloxacin, 7.487 ± 2.821 versus 6.912 ± 2.911, F = 4.060, P = 0.0452). The visual acuity and the tolerance after local application of the eye drops between the two groups had no difference (the visual acuity F = 1.04, P = 0.3080; the tolerance after local admission χ(2) = 0.1372, P = 0.7111). According to the result of the germ culture, the major pathogenic bacteria were Gram-positive bacteria (totally 20 kinds of Gram-positive bacteria and 8 kinds of Gram-negative bacteria). The MIC and drug resistance of gatifloxacin to the Gram-positive bacteria was lower than that of the levofloxacin (Staphylococcus Epidermidis, Staphylococcus Aureus, coagulase negative Staphylococcus, α-hemolytic Streptococcus). CONCLUSIONS: The gatifloxacin eye drop has a good therapeutic effect to the bacterial conjunctivitis. It can effectively clear the pathogen with fast and strong effect. Moreover, it has a low MIC in vitro, advance a prospect in drug resistance, safety and ocular tolerance.