Evolution of FLOWERING LOCUS T-like genes in angiosperms: a core Lamiales-specific diversification.

Plant life history is determined by two transitions, germination and flowering time, in which the phosphatidylethanolamine-binding proteins (PEBPs) FLOWERING LOCUS T (FT) and TERMINAL FLOWER1 (TFL1) play key regulatory roles. Compared with the highly conserved TFL1-like genes, FT-like genes vary significantly in copy numbers in gymnosperms, and monocots within the angiosperms, while sporadic duplications can be observed in eudicots. Here, via a systematic analysis of the PEBPs in angiosperms with a special focus on 12 representative species featuring high-quality genomes in the order Lamiales, we identified a successive lineage-specific but systematic expansion of FT-like genes in the families of core Lamiales. The first expansion event generated FT1-like genes mainly via a core Lamiales-specific whole-genome duplication (cL-WGD), while a likely random duplication produced the FT2-like genes in the lineages containing Scrophulariaceae and the rest of the core Lamiales. Both FT1- and FT2-like genes were further amplified tandemly in some families. These expanded FT-like genes featured highly diverged expression patterns and structural variation, indicating functional diversification. Intriguingly, some core Lamiales contained the relict MOTHER OF FT AND TFL1 like 2 (MFT2) that probably expanded in the common ancestor of angiosperms. Our data showcase the highly dynamic lineage-specific expansion of the FT-like genes, and thus provide important and fresh evolutionary insights into the gene regulatory network underpinning flowering time diversity in Lamiales and, more generally, in angiosperms.

Molecular and genetic regulation of petal number variation.

Floral forms with an increased number of petals, also known as double-flower phenotypes, have been selected and conserved in many domesticated plants, particularly in ornamentals, because of their great economic value. The molecular and genetic mechanisms that control this trait are therefore of great interest, not only for scientists, but also for breeders. In this review, we summarize current knowledge of the gene regulatory networks of flower initiation and development and known mutations that lead to variation of petal number in many species. In addition to the well-accepted miR172/AP2-like module, for which many questions remain unanswered, we also discuss other pathways in which mutations also lead to the formation of extra petals, such as those involved in meristem maintenance, hormone signalling, epigenetic regulation, and responses to environmental signals. We discuss how the concept of 'natural mutants' and recent advances in genomics and genome editing make it possible to explore the molecular mechanisms underlying double-flower formation, and how such knowledge could contribute to the future breeding and selection of this trait in more crops.

Genomes of Meniocus linifolius and Tetracme quadricornis reveal the ancestral karyotype and genomic features of core Brassicaceae.

Brassicaceae represents an important plant family from both a scientific and economic perspective. However, genomic features related to the early diversification of this family have not been fully characterized, especially upon the uplift of the Tibetan Plateau, which was followed by increasing aridity in the Asian interior, intensifying monsoons in Eastern Asia, and significantly fluctuating daily temperatures. Here, we reveal the genomic architecture that accompanied early Brassicaceae diversification by analyzing two high-quality chromosome-level genomes for Meniocus linifolius (Arabodae; clade D) and Tetracme quadricornis (Hesperodae; clade E), together with genomes representing all major Brassicaceae clades and the basal Aethionemeae. We reconstructed an ancestral core Brassicaceae karyotype (CBK) containing 9 pseudochromosomes with 65 conserved syntenic genomic blocks and identified 9702 conserved genes in Brassicaceae. We detected pervasive conflicting phylogenomic signals accompanied by widespread ancient hybridization events, which correlate well with the early divergence of core Brassicaceae. We identified a successive Brassicaceae-specific expansion of the class I TREHALOSE-6-PHOSPHATE SYNTHASE 1 (TPS1) gene family, which encodes enzymes with essential regulatory roles in flowering time and embryo development. The TPS1s were mainly randomly amplified, followed by expression divergence. Our results provide fresh insights into historical genomic features coupled with Brassicaceae evolution and offer a potential model for broad-scale studies of adaptive radiation under an ever-changing environment.

Hippocampal volume and resting-state functional connectivity on magnetic resonance imaging in patients with Parkinson and depression.

Background: Recent structural and functional imaging studies of depression in Parkinson disease (DPD) have failed to reveal the relevant mechanism, and relatively few studies have been conducted on limbic systems such as the hippocampus. This study thus aimed to gain new insights into the pathogenesis of DPD by detecting the changes in the hippocampal structure and the resting-state functional connectivity (FC) of patients with DPD. Methods: This study included 30 patients with DPD (DPD group), 30 patients with nondepressed Parkinson disease (NDPD; NDPD group), and 30 normal controls (NCs; NC group) with no significant age or gender differences with the DPD group. The Hamilton Depression Rating Scale (HAMD) and three-dimensional T1-weighted imaging and blood oxygen level-dependent imaging data of all patients were collected. The hippocampal volumes were measured using MATLAB software (MathWorks). The correlation between hippocampal volume and the HAMD score in the DPD group was analyzed with Pearson correlation coefficient. The bilateral hippocampi were used as the regions of interest and as the seed points for FC. FC analysis was performed between the preprocessed functional data of the whole brain and the two seed points with Data Processing Assistant for Resting-State and Statistical Parametric Mapping 8 software, respectively. The correlation between FC and HAMD scores in the patients with DPD was determined using partial correlation analysis. Results: Compared with those in the NC group and the NDPD group, the bilateral hippocampal volumes in the DPD group were significantly decreased (P<0.05). There was a negative correlation between the bilateral hippocampal volume and the HAMD score in the DPD group (P<0.05). Compared with that of the NDPD group, the FC of the right hippocampus with the right occipital lobe and left precuneus was reduced in the DPD group. In the DPD group, the FC values of the right hippocampus, right occipital lobe, and left anterior cuneiform lobe were negatively correlated with HAMD scores. Conclusions: The volume of bilateral hippocampi in patients with DPD is significantly decreased and negatively correlated with the severity of depressive disorder. The weakened FC of the right hippocampus to the right occipital lobe and the left precuneus may play an important role in the neurological basis of DPD.

A comparative full-length transcriptomic resource provides insight into the perennial monocarpic mass flowering.

Perennial monocarpic mass flowering represents as a key developmental innovation in flowering time diversity in several biological and economical essential families, such as the woody bamboos and the shrubby Strobilanthes. However, molecular and genetic mechanisms underlying this important biodiversity remain poorly investigated. Here, we generated a full-length transcriptome resource incorporated into the BlueOmics database (http://blueomics.iflora.cn) for two Strobilanthes species, which feature contrasting flowering time behaviors. Using about 112 and 104 Gb Iso-seq reads together with ~185 and ~75 Gb strand-specific RNA seq data, we annotated 80 971 and 79 985 non-redundant full-length transcripts for the perennial polycarpic Strobilanthes tetrasperma and the perennial monocarpic Strobilanthes biocullata, respectively. In S. tetrasperma, we identified 8794 transcripts showing spatiotemporal expression in nine tissues. In leaves and shoot apical meristems at two developmental stages, 977 and 1121 transcripts were differentially accumulated in S. tetrasperma and S. biocullata, respectively. Interestingly, among the 33 transcription factors showing differential expression in S. tetrasperma but without differential expression in S. biocullata, three were involved potentially in the photoperiod and circadian-clock pathway of flowering time regulation (FAR1 RELATED SEQUENCE 12, FRS12; NUCLEAR FACTOR Y A1, NFYA1; PSEUDO-RESPONSE REGULATOR 5, PRR5), hence provides an important clue in deciphering the flowering diversity mechanisms. Our data serve as a key resource for further dissection of molecular and genetic mechanisms underpinning key biological innovations, here, the perennial monocarpic mass flowering.

Association between napping and 24-hour blood pressure variability among university students: A pilot study.

Background: Blood pressure variability (BPV) has been reported to be a predictor of cardiovascular and some cognitive diseases. However, the association between napping and BPV remains unknown. This study aimed to explore the association between napping and BPV. Materials and methods: A cross-sectional study including 105 university students was conducted. Participants' 24 h ambulatory blood pressure monitoring (24 h ABPM) were measured, and napping behaviors were investigated. BPV were measured by the 24 h ABPM, included standard deviation (SD), coefficient of variation (CV), and average real variability (ARV). Results: Among the participants, 61.9% reported daytime napping. We found that nap duration was significantly associated with daytime CV of diastolic blood pressure (DBP) (r = 0.250, P = 0.010), nighttime CV of systolic blood pressure (SBP) (r = 0.217, P = 0.026), 24 h WCV of DBP (r = 0.238, P = 0.014), 24 h ARV of SBP (r = 0.246, P = 0.011) and 24 h ARV of DBP (r = 0.291, P = 0.003). Compared with the no napping group, 24 h WCV of DBP, daytime CV of DBP, and daytime SD of DBP were significantly higher in participants with napping duration >60 min. With multiple regression analysis we found that nap duration was an independent predictor for 24 h ARV of SBP (ß = 0.859, 95% CI, 0.101-1.616, P = 0.027) and 24 h ARV of DBP (ß = 0.674, 95% CI, 0.173-1.175, P = 0.009). Conclusions: Napping durations are associated with BPV among university students. Especially those with napping durations >60 min had a significantly higher BPV than those non-nappers.

Arabidopsis AGAMOUS-LIKE16 and SUPPRESSOR OF CONSTANS1 regulate the genome-wide expression and flowering time.

Flowering transition is tightly coordinated by complex gene regulatory networks, in which AGAMOUS-LIKE 16 (AGL16) plays important roles. Here, we identified the molecular function and binding properties of AGL16 and demonstrated its partial dependency on the SUPPRESSOR OF CONSTANS 1 (SOC1) function in regulating flowering. AGL16 bound to promoters of more than 2,000 genes via CArG-box motifs with high similarity to that of SOC1 in Arabidopsis (Arabidopsis thaliana). Approximately 70 flowering genes involved in multiple pathways were potential targets of AGL16. AGL16 formed a protein complex with SOC1 and shared a common set of targets. Intriguingly, only a limited number of genes were differentially expressed in the agl16-1 loss-of-function mutant. However, in the soc1-2 knockout background, AGL16 repressed and activated the expression of 375 and 182 genes, respectively, with more than a quarter bound by AGL16. Corroborating these findings, AGL16 repressed the flowering time more strongly in soc1-2 than in the Col-0 background. These data identify a partial inter-dependency between AGL16 and SOC1 in regulating genome-wide gene expression and flowering time, while AGL16 provides a feedback regulation on SOC1 expression. Our study sheds light on the complex background dependency of AGL16 in flowering regulation, thus providing additional insights into the molecular coordination of development and environmental adaptation.

Application of the maximum threshold distances to reduce gene flow frequency in the coexistence between genetically modified (GM) and non-GM maize.

On the coexistence of genetically modified (GM) and non-GM maize, the isolation distance plays an important role in controlling the transgenic flow. In this study, maize gene flow model was used to quantify the MTD0.1% and MTD1% in the main maize-planting regions of China; those were the maximum threshold distance for the gene flow frequency equal to or lower than 1% and 0.1%. The model showed that the extreme MTD1% and MTD0.1% were 187 and 548 m, respectively. The regions of northern China and the coastal plain, including Hainan crop winter-season multiplication base, showed a significantly high risk for maize gene flow, while the west-south of China was the largest low-risk areas. Except for a few sites, the isolation distance of 500 m could yield a seed purity of better than 0.1% and meet the production needs of breeder seeds. The parameters of genetic competitiveness (cp) were introduced to assess the effects of hybrid compatibility between the donor and recipient. The results showed that hybrid incompatibility could minimize the risk. When cp = 0.05, MTD1% and MTD0.1% could be greatly reduced within 19 m and 75 m. These data were helpful to provide scientific data to set the isolation distance between GM and non-GM maize and select the right place to produce the hybrid maize seeds.

Complex and reticulate origin of edible roses (Rosa, Rosaceae) in China.

While roses are today among the most popular ornamental plants, the petals and fruits of some cultivars have flavored foods for millennia. The genetic origins of these edible cultivars remain poorly investigated. We collected the major varieties of edible roses available in China, assembled their plastome sequences, and phased the haplotypes for internal transcribed spacers (ITS1/ITS2) of the 18S-5.8S-26S nuclear ribosomal cistron. Our phylogenetic reconstruction using 88 plastid genomes, of primarily maternal origin, uncovered well-supported genetic relationships within Rosa, including all sections and all subgenera. We phased the ITS sequences to identify potential donor species ancestral to the development of known edible cultivars. The tri-parental Middle-Eastern origin of R. × damascena, the species most widely used in perfume products and food additives, was confirmed as a descendent of past hybridizations among R. moschata, R. gallica, and R. majalis/R. fedtschenkoana/R. davurica. In contrast, R. chinensis, R. rugosa, and R. gallica, in association with six other wild species, were the main donors for fifteen varieties of edible roses. The domesticated R. rugosa 'Plena' was shown to be a hybrid between R. rugosa and R. davurica, sharing a common origin with R. 'Fenghua'. Only R. 'Jinbian' and R. 'Crimson Glory' featured continuous flowering. All remaining cultivars of edible roses bloomed only once a year. Our study provides important resources for clarifying the origin of edible roses and suggests a future for breeding new cultivars with unique traits, such as continuous flowering.

Comparison on nutritional quality of adult female Chinese mitten crab (Eriocheir sinensis) with different colored hepatopancreases.

White hepatopancreas syndrome has recently emerged in Chinese mitten crab (Eriocheir sinensis) aquaculture, causing considerable economic loss. The hepatopancreas color of diseased crabs becomes gradually lighter, turning from yellow to yellow-white to white. Therefore, this study was conducted to investigate the changes in nutrient composition in three edible parts (hepatopancreas, ovaries, and muscle) of adult females with different colored hepatopancreases. Three groups were assessed in this study, including a yellow hepatopancreas group (control, L * = 63.92, a * = 22.14, b * = 60.95), a yellow-white hepatopancreas group (YWHG, L * = 65.06, a * = 22.35, b * = 57.80), and a white hepatopancreas group (WHG, L * = 65.72, a * = 10.70, b * = 30.52). No statistically significant differences in average weight, tissue indices, and total edible yield were observed among the three crab groups (P >0.05). The moisture content of the hepatopancreases and ovaries in WHG was 56.12% and 9.23% higher than the control values (P <0.05), whereas hepatopancreas crude fat and ovary crude protein levels were 62.23% and 11.45% lower than the control values (P < 0.05). The total carbohydrate levels of the three edible tissues were significantly higher and the crude protein content of ovaries was significantly lower in YWHG (P < 0.05). Most amino acid levels in the WHG muscle and ovaries were significantly lower than the control (P < 0.05). Moreover, the hepatopancreas levels of total polyunsaturated fatty acids (PUFA) and n-6PUFA in WHG were 24.88% and 31.83% lower than in control group, whereas the hepatopancreas levels of total PUFA and n-6PUFA in YWHG were also 21.88% and 23.20% lower compared to the controls (P < 0.05). Overall, the growth and the edible parts were not affected in YWHG and WHG. Moreover, YWHG crabs exhibited few effects on nutritional value; however, the fatty acid composition of crabs was significantly changed. In contrast, WHG crabs exhibited poor nutritional quality. Nonetheless, the consumption of crabs with yellow-white or white hepatopancreases is not recommended since the animal also referred to as diseased crabs.

Expansion and expression diversity of FAR1/FRS-like genes provides insights into flowering time regulation in roses.

Roses are important horticultural plants with enormous diversity in flowers and flowering behavior. However, molecular regulation of flowering time variation in roses remains poorly characterized. Here, we report an expansion of the FAR1/FRS-like genes that correlates well with the switch to prostrate-to-erect growth of shoots upon flowering in Rosa wichuraiana 'Basye's Thornless' (BT). With the availability of the high-quality chromosome-level genome assembly for BT that we developed recently, we identified 91 RwFAR1/FRS-like genes, a significant expansion in contrast to 52 in Rosa chinensis 'Old Blush' (OB), a founder genotype in modern rose domestication. Rose FAR1/FRS-like proteins feature distinct variation in protein domain structures. The dispersed expansion of RwFAR1/FRS-like genes occurred specifically in clade I and II and is significantly associated with transposon insertion in BT. Most of the RwFAR1/FRS-like genes showed relatively higher expression level than their corresponding orthologs in OB. FAR1/FRS-like genes regulate light-signaling processes, shade avoidance, and flowering time in Arabidopsis thaliana. Therefore, the expansion and duplication of RwFAR1/FRS-like genes, followed by diversification in gene expression, might offer a novel leverage point for further understanding the molecular regulation of the variation in shoot-growth behavior and flowering time in roses.

Rose without prickle: genomic insights linked to moisture adaptation.

Prickles act against herbivores, pathogens or mechanical injury, while also preventing water loss. However, whether prickles have new function and the molecular genetics of prickle patterning remain poorly explored. Here, we generated a high-quality reference genome assembly for 'Basye's Thornless' (BT), a prickle-free cultivar of Rosa wichuraiana, to identify genetic elements related to stem prickle development. The BT genome harbors a high level of sequence diversity in itself and with cultivar 'Old Blush' (R. chinensis), a founder genotype in rose domestication. Inheritance of stem prickle density was determined and two QTL were identified. Differentially expressed genes in QTL were involved in water-related functions, suggesting that prickle density may hitchhike with adaptations to moist environments. While the prickle-related gene-regulatory-network (GRN) was highly conserved, the expression variation of key candidate genes was associated with prickle density. Our study provides fundamental resources and insights for genome evolution in the Rosaceae. Ongoing efforts on identification of the molecular bases for key rose traits may lead to improvements for horticultural markets.

Genome-wide identification of WD40 genes reveals a functional diversification of COP1-like genes in Rosaceae.

KEY MESSAGE: Genome-wide identification of WD40-like genes reveals a duplication of COP1-like genes, one of the key players involved in regulation of flowering time and photomorphogenesis, with strong functional diversification in Rosaceae. WD40 proteins play crucial roles in a broad spectrum of developmental and physiological processes. Here, we conducted a systematic characterization of this family of genes in Rosa chinensis 'Old Blush' (OB), a founder genotype for modern rose domestication. We identified 187 rose WD40 genes and classified them into 5 clusters and 15 subfamilies with 11 of RcWD40s presumably generated via tandem duplication. We found RcWD40 genes were expressed differentially following stages of vegetative and reproductive development. We detected a duplication of CONSTITUTIVE PHOTOMORPHOGENIC1-like genes in rose (RcCOP1 and RcCOP1L) and other Rosaceae plants. Featuring a distinct expression pattern and a different profile of cis-regulatory-elements in the transcriptional regulatory regions, RcCOP1 seemed being evolutionarily conserved while RcCOP1L did not dimerize with RcHY5 and RcSPA4. Our data thus reveals a functional diversification of COP1-like genes in Rosacaeae plants, and provides a valuable resource to explore the potential function and evolution of WD40-like genes in Rosaceae plants.

Apatinib Combined with Local Irradiation Leads to Systemic Tumor Control via Reversal of Immunosuppressive Tumor Microenvironment in Lung Cancer.

PURPOSE: This study aimed to investigate the potential systemic antitumor effects of stereotactic ablative radiotherapy (SABR) and apatinib (a novel vascular endothelial growth factor receptor 2 inhibitor) via reversing the immunosuppressive tumor microenvironment for lung carcinoma. MATERIALS AND METHODS: Lewis lung cancer cells were injected into C57BL/6 mice in the left hindlimb (primary tumor; irradiated) and in the right flank (secondary tumor; nonirradiated). When both tumors grew to the touchable size, mice were randomly divided into eight treatment groups. These groups received normal saline or three distinct doses of apatinib (50 mg/kg, 150 mg/kg, and 200 mg/kg) daily for 7 days, in combination with a single dose of 15 Gy radiotherapy or not to the primary tumor. The further tumor growth/regression of mice were followed and observed. RESULTS: For the single 15 Gy modality, tumor growth delay could only be observed at the primary tumor. When combining SABR and apatinib 200 mg/kg, significant retardation of both primary and secondary tumor growth could be observed, indicated an abscopal effect was induced. Mechanism analysis suggested that programmed death-ligand 1 expression increased with SABR was counteract by additional apatinib therapy. Furthermore, when apatinib was combined with SABR, the composition of immune cells could be changed. More importantly, this two-pronged approach evoked tumor antigen-specific immune responses and the mice were resistant to another tumor rechallenge, finally, long-term survival was improved. CONCLUSION: Our results suggested that the tumor microenvironment could be managed with apatinib, which was effective in eliciting an abscopal effect induced by SABR.

[Toxicity of PM2.5 Based on a Battery of Bioassays].

To accurately evaluate the biotoxicity of PM2.5, PM2.5 samples from winter fog-haze days, winter normal days, and summer days in Changzhou were selected for evaluation based on the acute toxicity of luminescent bacteria and zebrafish embryos and the cytotoxicity of human lung adenocarcinoma cells in vitro (A549). The three atmospheric conditions and the physical and chemical indicators were also evaluated using correlation analysis. The PM2.5 samples showed either acute or developmental toxicity during all three periods. The toxicity unit (TU) of the luminescent bacteria for the winter fog-haze days, winter normal days, and summer days were 1.74 (toxic), 1.19 (toxic), and 0.92 (slightly toxic), respectively. The maximum TU of the zebrafish embryos was for winter normal days (TU=1.14, toxic) followed by winter fog-haze days (TU=0.79, slightly toxic), and summer days (TU=0, non-toxic). The highest TU of A549 was for winter fog-haze days (TU=0.61, toxic) followed by summer days (TU=0.38, toxic) and winter normal days (TU=0.31, toxic). With respect to developmental toxicity, with the exception of summer day samples, the PM2.5 samples from the other two periods had detrimental effects on the development of zebrafish embryos, mainly showing pericardial edema, a bent notochord, and tail deformity. The average toxicity (AvTx), toxic print (TxPr), and most sensitive test (MST) indices showed that the PM2.5 samples from winter fog-haze days and winter normal days exhibited toxicity, while samples from the summer days showed slight toxicity; PM2.5 samples from winter fog-haze days had the highest level of comprehensive toxicity. In addition, luminescent bacteria were the most sensitive to PM2.5 samples, followed by zebrafish embryos and A549. The results of chemical analysis and biological toxicity tests show that the pollutants contained in PM2.5 have a biological toxicity effect, which can provide a basis for the comprehensive assessment of PM2.5 biological toxicity and human health risks.

[Stability characteristics of soil organic carbon pool following development of sand-fixing forest in Mu Us sandy land, China]. / æ¯›ä¹Œç´ æ²™åœ°å›ºæ²™æž—å‘è‚²è¿‡ç¨‹ä¸­åœŸå£¤æœ‰æœºç¢³åº“ç¨³å®šæ€§ç‰¹å¾.

The study aimed to reveal the cumulative effects and stability characteristics of soil organic carbon (SOC) during forest development at the Mu Us sandy land, China. Using space for time substitution, surface soil samples were collected from semi-fixed sandy lands and restored arbor and shrub lands with the ages of 22, 32 and 53 years in the Yulin sand control region in Northern Shaanxi Province. The content of total organic carbon (TOC), oxidizable labile organic carbon, and resistant carbon and the characteristics of mineralized carbon emission and decomposition ratio were analyzed. The results showed that the increment of TOC for 22 to 53 years shrub and arbor lands from resistant carbon were 3.5-6.2 g·kg-1 and 3.2-7.7 g·kg-1, and from oxidized labile carbon were 2.8-3.4 g·kg-1 and 1.3-2.8 g·kg-1, respectively, compared with semi-fixed sand land. The ratio of soil oxidizable labile carbon in shrub land and arbor land were stable and maintained at 37.0% and 26.8%, respectively. However, the ratio decreased to 25.7% and 17.4% after incubated at a constant temperature for 60 days. The mineralization rate of shrub and arbor lands with 22-53 years was not significant at the ending of soil incubation. Carbon losses from oxidized liable carbon were 76.9%-98.7%, and only 1.3%-23.5% from resistant carbon in all sand-fixing forest plots. Compared with the maximum carbon emission rate, the soil cumulative carbon release exhibited a higher correlation with soil enzyme activities of ß-glucosidase and dehydrogenase, but the enzyme activities did not change from 32-53 years. In conclusion, SOC pool showed stable characteristics of lower emission and higher sequestration with the increases of sand-fixing forest stand age. The carbon fixation effect of arbor sand-fixing forest was better than that of shrub sand-fixing forest.

Periodic surface structures on dielectrics upon femtosecond laser pulses irradiation.

The formation of laser-induced periodic surface structures (LIPSS) on two different dielectrics of K9 glass and fused silica upon irradiation in ambient conditions and in vacuum with multiple femtosecond (fs) laser pulse sequences at different pulse durations (35 fs, 260 fs, and 500 fs) was studied experimentally. Three types of LIPSS, so-called high-spatial-frequency LIPSS (HSFL), low-spatial-frequency LIPSS (LSFL), and supra-wavelength periodic surface structures (SWPSS) with different spatial periods and orientations were identified. The appearance was characterized with respect to the experimental parameters of laser fluence and number of laser pulses per spot. The crater morphologies - including nanoripples, periodic microgrooves, quasiperiodic microspikes, and central smooth zone - were observed by scanning electron microscope (SEM). The supra-wavelength structures exhibit periodicities, which are markedly, even multiple times, higher than the laser excitation wavelength. The SWPSS were formed with a broader range of laser fluences, upon the longer laser pulse durations (260 fs and 500 fs) and/or on the lower band-gap dielectrics (K9 glass), due to the deeper effective light penetration depths and thicker viscous surface layers formation. The HSFL were observed on the higher band-gap dielectrics (fused silica) and within a certain narrow laser parameter window. The formation mechanisms of LIPSS were also discussed.

[Distribution Characteristics of Antibiotic Resistance Genes in PM2.5 of a Concentrated Broiler Feeding Operation].

Concentrated poultry feeding operations are an important source of antibiotic resistance genes (ARGs). Little attention has been given to PM2.5 as a mechanism for exposing ARGs to humans. In this study, PM2.5 and fecal samples from inside the broiler feeding operation and PM2.5 samples from outside the broiler feeding operation were collected. All samples were subjected to the determination of class Ⅰ integrin (intI1), total bacterial gene (16S rDNA), and 19 ARGs of six types by quantitative real-time PCR (qPCR). The results indicated that, excluding blaGES-1 and blaSHV-1, the remaining 17 ARGs were detected in all six samples. Sulfonamide resistance genes, tetracycline resistance genes, macrolide resistance genes, and aminoglycoside resistance genes were abundant in the feces, reaching 1.04×109-3.27×1010 copies·g-1, while feces was an important source of antibiotic resistance genes in PM2.5 of the broiler feeding operation. There were high abundances of sulfonamide resistance genes and macrolide resistance genes in PM2.5 from inside the broiler feeding operation, reaching (8.9±1.9)×107 copies·m-3 and (5.6±3.1)×107 copies·m-3, respectively. The abundance of ARGs in the PM2.5 samples from inside the broiler feeding operation was significantly higher compared to the outside PM2.5 samples. There was a significant positive correlation between PM2.5 mass concentration and 16S rDNA, intI1, and ARGs abundance, indicating that PM2.5 was the reservoir and disseminator of airborne bacteria, ARGs, and intI1 in the broiler feeding operation. The abundance of intI1 was higher than ARGs among all samples, and the co-occurring relationship between intI1 and ARGs demonstrates the threat of multi-drug resistance, which is harmful to the surrounding air environment and the health of the breeder and poultry.