Compact, low-loss, and high-polarized-extinction ratio terahertz TM-pass polarizer based on a hybrid plasmonic waveguide with a graphene ridge.

A compact, low-loss, and high-polarized-extinction ratio TM-pass polarizer based on a graphene hybrid plasmonic waveguide (GHPW) has been demonstrated for the terahertz band. A ridge coated by a graphene layer and the hollow HPW with a semiround arch (SRA) Si core is introduced to improve structural compactness and suppress the loss. Based on this, a TM-pass polarizer has been designed that can effectively cut off the unwanted TE mode, and the TM mode passes with negligible loss. By optimizing the angle of the ridge, the height of the ridge, air gap height, and the length of the tapered mode converter, an optimum performance with a high polarization extinction ratio of 30.28 dB and a low insert loss of 0.4 dB is achieved in the 3 THz band. This work provides a scheme for the design and optimization of polarizers in the THz band, which has potential application value in integrated terahertz systems.

Inter-/intra-pulse dual-wavelength-operated mid-infrared optical parametric oscillator.

We demonstrate a pulsed mid-infrared (MIR) optical parametric oscillator (OPO) with both inter-pulse and intra-pulse dual-wavelength operation capability. A fiber master oscillator power amplifier incorporating an acousto-optic tunable filter (AOTF) was employed as the pump for the OPO. By finely adjusting the drive wave packets for the AOTF, dual-wavelength pump can be realized within each pulse or between two adjacent pulses. These special temporal-spectral behaviors of the pump can be transferred to MIR via an OPO. In the proof-of-principle experiments, two pump wavelengths at ∼1065 and ∼1076 nm were generated and amplified to ∼31.2 W with equivalent spectral intensities for both pulsation modes. At the highest pump power, total idler power of ∼3.5 W was achieved at ∼3.45 and ∼3.55 µm under both pulsation modes. To the best of our knowledge, this is the first demonstration of both inter-pulse and intra-pulse dual-wavelength MIR generation via an OPO with an identical configuration. It is believed that our design may provide a promising solution to many practical applications including differential absorption lidar and tunable terahertz wave generation.

Plant domestication shapes rhizosphere microbiome assembly and metabolic functions.

BACKGROUND: The rhizosphere microbiome, which is shaped by host genotypes, root exudates, and plant domestication, is crucial for sustaining agricultural plant growth. Despite its importance, how plant domestication builds up specific rhizosphere microbiomes and metabolic functions, as well as the importance of these affected rhizobiomes and relevant root exudates in maintaining plant growth, is not well understood. Here, we firstly investigated the rhizosphere bacterial and fungal communities of domestication and wild accessions of tetraploid wheat using amplicon sequencing (16S and ITS) after 9 years of domestication process at the main production sites in China. We then explored the ecological roles of root exudation in shaping rhizosphere microbiome functions by integrating metagenomics and metabolic genomics approaches. Furthermore, we established evident linkages between root morphology traits and keystone taxa based on microbial culture and plant inoculation experiments. RESULTS: Our results suggested that plant rhizosphere microbiomes were co-shaped by both host genotypes and domestication status. The wheat genomes contributed more variation in the microbial diversity and composition of rhizosphere bacterial communities than fungal communities, whereas plant domestication status exerted much stronger influences on the fungal communities. In terms of microbial interkingdom association networks, domestication destabilized microbial network and depleted the abundance of keystone fungal taxa. Moreover, we found that domestication shifted the rhizosphere microbiome from slow growing and fungi dominated to fast growing and bacteria dominated, thereby resulting in a shift from fungi-dominated membership with enrichment of carbon fixation genes to bacteria-dominated membership with enrichment of carbon degradation genes. Metagenomics analyses further indicated that wild cultivars of wheat possess higher microbial function diversity than domesticated cultivars. Notably, we found that wild cultivar is able to harness rhizosphere microorganism carrying N transformation (i.e., nitrification, denitrification) and P mineralization pathway, whereas rhizobiomes carrying inorganic N fixation, organic N ammonification, and inorganic P solubilization genes are recruited by the releasing of root exudates from domesticated wheat. More importantly, our metabolite-wide association study indicated that the contrasting functional roles of root exudates and the harnessed keystone microbial taxa with different nutrient acquisition strategies jointly determined the aboveground plant phenotypes. Furthermore, we observed that although domesticated and wild wheats recruited distinct microbial taxa and relevant functions, domestication-induced recruitment of keystone taxa led to a consistent growth regulation of root regardless of wheat domestication status. CONCLUSIONS: Our results indicate that plant domestication profoundly influences rhizosphere microbiome assembly and metabolic functions and provide evidence that host plants are able to harness a differentiated ecological role of root-associated keystone microbiomes through the release of root exudates to sustain belowground multi-nutrient cycles and plant growth. These findings provide valuable insights into the mechanisms underlying plant-microbiome interactions and how to harness the rhizosphere microbiome for crop improvement in sustainable agriculture. Video Abstract.

Quantitative Measurement Reveals Dynamic Volatile Changes and Potential Biochemical Mechanisms during Green Tea Spreading Treatment.

Quantitative data provide clues for biochemical reactions or regulations. The absolute quantification of volatile compounds in tea is complicated by their low abundance, volatility, thermal liability, matrix complexity, and instrumental sensitivity. Here, by integrating solvent-assisted flavor evaporation extraction with a gas chromatography-triple quadrupole mass spectrometry platform, we successfully established a method based on multiple reaction monitoring (MRM). The method was validated by multiple parameters, including the linear range, limit of detection, limit of quantification, precision, repeatability, stability, and accuracy. This method was then applied to measure temporal changes of endogenous volatiles during green tea spreading treatment. In total, 38 endogenous volatiles were quantitatively measured, which are derived from the shikimic acid pathway, mevalonate pathway, 2-C-methylerythritol-4-phosphate pathway, and fatty acid derivative pathway. Hierarchical clustering and heat-map analysis demonstrated four different changing patterns during green tea spreading treatment. Pathway analysis was then conducted to explore the potential biochemistry underpinning these dynamic change patterns. Our data demonstrated that the established MRM method showed high selectivity and sensitivity for quantitative tea volatile measurement and offered novel insights about volatile formation during green tea spreading.

Survival and causes of death among people with clinically diagnosed dementia with Lewy bodies: A multicenter cohort study.

OBJECTIVE: A comprehensive study of the survival and causes of death of people with clinically diagnosed Dementia with Lewy bodies (DLB) were few. The aim of our study was to investigate the survival and causes of death of DLB. METHODS: The patients diagnosed with probable DLB were consecutively enrolled from five memory clinics in China across a 5-year period (2017-2021) with mortality data updated to December 2021. The endpoint was all-cause death. Survival analysis including Cox regression by groups (time both from disease onset and the first visit to death) and causes of death were evaluated. RESULTS: Of the 108 patients with DLB, 54 (50%) were men and the time from onset of disease to the first visit to the memory clinic (lag time) was 24 (12-48) months. During follow-up, 28.7% (n = 31) of the patients died. The median survival time both from disease onset and the first visit were 81 (95% cognitive impairment (CI) 69.09-92.91) and 45 (95% CI 34.78-55.22) months, respectively. The use of antipsychotic drugs (HR 0.15, 95% CI: 0.03-0.75), moderate to severe dementia (Clinical Dementia Rating [CDR]) at the first visit (HR 0.22, 95% CI 0.78 to 0.62) and the longer lag time (HR 0.943, 95% CI 0.92-0.97) predicted a shorter survival. Failure to thrive (stopped eating, drinking) or multiple organ dysfunction syndrome (MODS) maybe the most common cause of death (41.7%), followed by pneumonia or aspiration (29.2%). CONCLUSIONS: The factors associated with survival time were disease severity level, antipsychotic drug use and lag time to seek medical advice. Failure to thrive or MODS and pneumonia were probably the most common cause of death. The long-term outcomes of DLB patients may be helpful to guide clinicians counseling patients and caregivers.

Metabolomic Profiling in Combination with Data Association Analysis Provide Insights about Potential Metabolic Regulation Networks among Non-Volatile and Volatile Metabolites in Camellia sinensis cv Baijiguan.

The non-volatile and volatile metabolites in tea confer the taste and odor characteristics of tea fusion, as well as shape the chemical base for tea quality. To date, it remains largely elusive whether there are metabolic crosstalks among non-volatile metabolites and volatile metabolites in the tea tree. Here, we generated an F1 half-sib population by using an albino cultivar of Camellia sinensis cv Baijiguan as the maternal parent, and then we quantified the non-volatile metabolites and volatile metabolites from individual half-sibs. We found that the EGC and EGCG contents of the albino half-sibs were significantly lower than those of the green half-sibs, while no significant differences were observed in total amino acids, caffeine, and other catechin types between these two groups. The phenylpropanoid pathway and the MEP pathway are the dominant routes for volatile synthesis in fresh tea leaves, followed by the MVA pathway and the fatty acid-derivative pathway. The total volatile contents derived from individual pathways showed large variations among half-sibs, there were no significant differences between the albino half-sibs and the green half-sibs. We performed a comprehensive correlation analysis, including correlations among non-volatile metabolites, between volatile synthesis pathways and non-volatile metabolites, and among the volatiles derived from same synthesis pathway, and we identified several significant positive or negative correlations. Our data suggest that the synthesis of non-volatile and volatile metabolites is potentially connected through shared intermediates; feedback inhibition, activation, or competition for common intermediates among branched pathways may co-exist; and cross-pathway activation or inhibition, as well as metabolome channeling, were also implicated. These multiple metabolic regulation modes could provide metabolic plasticity to direct carbon flux and lead to diverse metabolome among Baijiguan half-sibs. This study provides an essential knowledge base for rational tea germplasm improvements.

Integrate Small RNA and Degradome Sequencing to Reveal Drought Memory Response in Wheat (Triticum aestivum L.).

Drought has gradually become one of the most severe abiotic stresses on plants. Plants that experience stress training can exhibit enhanced stress tolerance. According to MicroRNA (miRNA) sequencing data, this study identified 195 candidate drought memory-related miRNAs in wheat, and targets of 64 (32.8%) candidate miRNAs were validated by degradome sequencing. Several drought memory-related miRNAs such as tae-miR9676-5p, tae-MIR9676-p3_1ss21GA, tae-miR171a, tae-miR531_L-2, tae-miR408_L-1, PC-3p-5049_3565, tae-miR396c-5p, tae-miR9778, tae-miR164a-5p, and tae-miR9662a-3p were validated as having a strong response to drought memory by regulating the expression of their target genes. In addition, overexpression of drought memory-related miRNA, tae-miR531_L-2, can remarkably improve the drought tolerance of transgenic Arabidopsisthaliana. Drought memory can regulate plant cellular signal transduction, plant biosynthetic processes, and other biological processes to cope with drought via transcriptional memory. In addition, drought memory-related miRNAs can promote starch and sucrose catabolism and soluble sugar accumulation and regulate proline homeostasis to improve plant drought resistance. Our results could contribute to an understanding of drought memory in wheat seedlings and may provide a new strategy for drought-resistant breeding.

The Landscape of Autophagy-Related (ATG) Genes and Functional Characterization of TaVAMP727 to Autophagy in Wheat.

Autophagy is an indispensable biological process and plays crucial roles in plant growth and plant responses to both biotic and abiotic stresses. This study systematically identified autophagy-related proteins (ATGs) in wheat and its diploid and tetraploid progenitors and investigated their genomic organization, structure characteristics, expression patterns, genetic variation, and regulation network. We identified a total of 77, 51, 29, and 30 ATGs in wheat, wild emmer, T. urartu and A. tauschii, respectively, and grouped them into 19 subfamilies. We found that these autophagy-related genes (ATGs) suffered various degrees of selection during the wheat's domestication and breeding processes. The genetic variations in the promoter region of Ta2A_ATG8a were associated with differences in seed size, which might be artificially selected for during the domestication process of tetraploid wheat. Overexpression of TaVAMP727 improved the cold, drought, and salt stresses resistance of the transgenic Arabidopsis and wheat. It also promoted wheat heading by regulating the expression of most ATGs. Our findings demonstrate how ATGs regulate wheat plant development and improve abiotic stress resistance. The results presented here provide the basis for wheat breeding programs for selecting varieties of higher yield which are capable of growing in colder, drier, and saltier areas.

Macro-composition quantification combined with metabolomics analysis uncovered key dynamic chemical changes of aging white tea.

It is a common belief in China that aging could improve the quality of white tea. However, the stored-induced compositional changes remain elusive. In this study, ten subsets of white tea samples, which had been stored for 1-, 2-, 3-, 4-, 5-, 6-, 7-, 10-, 11- and 13- years, were selected. Macro-compositions were quantified firstly. As the results showed, it was interesting to find total flavonoids, thearubigins (TRs), and theabrownines (TBs) increasing, accompanied with a gradual decrease of total polyphenols, which suggest a conversion of phenolic component in the aging process. Then, nontargeted metabolomics was further conducted on selected subsets of samples, including 1-, 7- and 13- years stored to profile their conversion. As a result, most different metabolites were related to flavonol glycosides and flavone glycosides, suggesting dynamic phenolic component changes were vital in aging. The partial least-squares-discriminant analysis (PLS-DA) also identified them as markers in distinguishing.

Widely Targeted Metabolomics Analysis Reveals Great Changes in Nonvolatile Metabolites of Oolong Teas during Long-Term Storage.

As a semifermented tea, oolong is exceedingly popular worldwide for its elegant, flowery aroma and mellow, rich taste. However, recent marketing trends for old oolong teas and their chemical quality largely remain unexplored. In this study, we applied widely targeted metabolomics using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) combined with multivariate analysis to investigate the chemical change of oolong teas in the aging process. With the increasing of store time, most nongalloylated catechins; tannins, including TFs and proanthocyanidins; flavonols and glycosylated flavonols; amino acids and their derivatives; nucleotides and their derivatives; and lots of alkaloids and phospholipids declined, while most fatty acids and organic acids increased, and galloylated catechins, GA, and caffeine were almost stable. The result also suggested that approximately seven years (but not an infinite extension) was a special period for oolong tea storage, which brings about excellent taste.

Flexible wavelength generation from a Yb-doped fiber laser incorporating multifunctional acousto-optic tunable filter.

We have demonstrated a Yb-doped fiber laser (YDFL) based on a multifunctional acousto-optic tunable filter (AOTF) with flexible wavelength generation capability. The number of channels, as well as their diffracted wavelengths and corresponding peak transmittances of the AOTF, can be widely tuned by changing the composite drive signal from a homemade arbitrary wave generation (AWG) board enabling single-/multi-wavelength lasing with different central wavelengths and relative intensities. The maximal wavelength tuning range and minimal resolved wavelength spacing are ∼80nm and ∼1.5nm, respectively, with 3 dB bandwidth less than 0.15 nm for each laser line, showing great potential for further nonlinear frequency conversion. To the best of our knowledge, this is the first demonstration of flexible wavelength generation from a multifunctional AOTF-based YDFL directly driven by an AWG board.

Prealbumin and D-dimer as Prognostic Indicators for Rebleeding in Patients with Nonvariceal Upper Gastrointestinal Bleeding.

BACKGROUND: Determining the risk stratification of nonvariceal upper gastrointestinal bleeding (NVUGIB) plays a vital role in treating upper gastrointestinal bleeding (UGIB). Traditional scores like Glasgow-Blatchford score (GBS), Rockall score (RS), and AIMS65 score have been widely utilized in UGIB practice, however exhibiting limited practical use due to relative lack of user-friendly characters. Prealbumin as a nutritional indicator and d-dimer as a fibrinolytic activity monitor, are generally used to evaluate the overall nutritional and fibrinolytic condition in UGIB patients. AIMS: Here, we explored the predictive value of these two markers in NVUGIB for evaluating severity and prognosis including rebleeding and surgery intervention. METHODS: One hundred and eighty-five patients suffering NVUGIB were enrolled. Their GBS, RS, and AIMS65 score, routine laboratory test results including prealbumin and d-dimer were determined after admission. Multivariate regression analysis was performed to define the independent predictors of rebleeding. ROC curves were generated to compare the suitability of prealbumin, d-dimer, and scores for rebleeding prediction. RESULTS: The NVUGIB patients with rebleeding exhibited higher scores, white blood cell counts, d-dimer, CRP, proportion of surgery intervention, and longer hospital stay, but lower hematocrit, hemoglobin, calcium, prealbumin, and fibrinogen than those without rebleeding. The multivariate regression analysis demonstrated that prealbumin and d-dimer were independent predictors for rebleeding. Values of prealbumin and d-dimer were correlated with hospital stay, ulcer degrees, and surgery demand. The ROC curve analyses showed that prealbumin and d-dimer exhibited superior prediction value over the scoring systems. CONCLUSIONS: Prealbumin and d-dimer are promising predictors for severity and prognosis in NVUGIB practice.

Identification and comparison of oligopeptides during withering process of White tea by ultra-high pressure liquid chromatography coupled with quadrupole-orbitrap ultra-high resolution mass spectrometry.

Peptides could have specific tastes or bioactivities depending on the length and sequence of amino acids. Till date it remains unknown what peptides are formed during the white tea manufacturing process and whether they contribute to the flavor or bio-activities of white tea. As a first step to address these questions, we applied ultra-high pressure liquid chromatography coupled with quadrupole-orbitrap ultra-high resolution mass spectrometry (UPLC-Quadrupole-Orbitrap-UHRMS) to monitor peptides dynamic changes during the withering process. A total of 196 abundant peptides were identified. Most of them were oligopeptides within a molecular weight of 1000 Da. Four of them were randomly selected, synthesized peptides were applied for further confirmation and quantification. Sequence analysis suggested that some of them were potential taste contributors. Proteinase cleave site analysis identified two separate periods of active proteins degradation at 0-12 h and 30-42 h of the withering processes. Further analysis of cleavage sites also suggested that protein degradation during withering steps were random rather than a stepwise reaction.

Curcumin ameliorates dextran sulfate sodium-induced colitis in mice via regulation of autophagy and intestinal immunity.

BACKGROUND/AIMS: Inflammatory bowel disease (IBD) is regarded as a kind of chronic and unspecific intestinal inflammatory disorder. Its exact pathogenesis has not been elucidated. Curcumin, as an herbal drug, has been used in the treatment of IBD due to its immunoregulation. Autophagy has been reported to play an important role in the mechanism of IBD. In the present study, we focused on the autophagic regulation role of curcumin in the murine model of dextran sulfate sodium (DSS)-induced colitis. MATERIALS AND METHODS: We investigated the effects of curcumin on the progress of DSS-induced acute colitis in mice by evaluating the disease activity index (DAI) and histopathological score. Meanwhile, the mRNA and protein expression of autophagy-related key genes from colon tissues comprising autophagy-related 5 (ATG5), LC3-phosphatidylethanolamine conjugate (LC-3II), beclin-1, and B cell lymphoma 2 (bcl-2) was examined by quantitative reverse transcription polymerase chain reaction and Western blot. Furthermore, the mRNA and protein expression of cytokines, including tumor necrosis factor (TNF)-α, interleukin (IL) 6, IL-10, and IL-17A, was examined. Autophagosome was also examined under transmission electron microscopy. RESULTS: Both DAI and histopathological score increased in mice with DSS-induced colitis and obviously decreased after curcumin intervention. The expression levels of TNF-α, IL-6, IL-17, ATG5, LC-3II, and beclin-1 were significantly higher in mice with colitis than in normal ones, whereas those of IL-10 and bcl-2 decreased accordingly. However, curcumin intervention adjusted the expression level of those factors toward normal level. The number of autophagosome in the colon epithelia increased after DSS stimulation and decreased after curcumin administration. CONCLUSION: Curcumin could prevent the development of DSS-induced colitis through the inhibition of excessive autophagy and regulation of following cytokine networks.

How would serum 25(OH)D level change in patients with inflammatory bowel disease depending on intestinal mucosa vitamin D receptor (VDR) and vitamin D1-α hydroxylase (CYP27B1)?

BACKGROUND/AIMS: To investigate how the serum 25-hydroxyvitamin D (25(OH)D) level change in patients with inflammatory bowel disease (IBD) and investigate the intestinal mucosa vitamin D receptor (VDR) and vitamin D1-α hydroxylase (CYP27B1) expressions. MATERIALS AND METHODS: A total of 105 patients with IBD were enrolled in the present study, including 49 cases with ulcerative colitis (UC) and 56 cases with Crohn's disease (CD), compared with 45 healthy controls (CON) during the same period by testing the permeability of the intestinal mucosa. The expressions of VDR and CYP27B1 in the intestinal mucosa were detected, so as the serum endotoxin, tumor necrosis factor (TNF)-α, and 25(OH)D levels. RESULTS: The lactulose and mannitol absorption ratio (LMR) and serum endotoxin and TNF-α levels were significantly higher in the IBD group than in the CON group (p<0.05). The levels of LMR, endotoxin, and TNF-α were higher in the UC group than in the CD group, but 25(OH)D was lower (p<0.05). VDR in the IBD and UC groups was down-regulated when compared with the CON group (p<0.05), but there was no significance between them (p>0.05). CYP27B1 in the IBD and CD groups was significantly up-regulated compared with the CON group (p<0.05), with no significant difference between them (p>0.05). CONCLUSION: Patients with IBD exhibit vitamin D metabolism imbalance, lower serum 25(OH)D, and lower VDR expression, but higher CYP27B1 expression in the colonic mucosa. However, VDR and CYP27B1 cannot be used to distinguish UC and CD.

Non-targeted metabolomics reveals distinct chemical compositions among different grades of Bai Mudan white tea.

So far, the chemical quality of different grades of white tea has largely remained unexplored. The objective of this study was to establish a model for quality evaluation of different grades of Bai Mudan white tea. We applied non-targeted ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry in combination with multivariate analysis and analyzed four different grades of Bai Mudan white tea. We found that the metabolite composition from the super-grade and the first-grade shared higher similarity compared to the second-grade or the third-grade white tea, and the Partial Least Square-Discriminant Analysis model showed high capability to explain the sample variation (R2Y = 0.998, Q2 = 0.95 in negative ionization modes). In total, 93 metabolites were structurally identified, wherein 21 low abundant metabolites showed distinct changes in abundance that were closely correlated with tea grade variation. These findings suggested their potential as markers to discriminate different grades of Bai Mudan white tea.

Genome-wide sequence and expressional analysis of autophagy Gene family in bread wheat (Triticum aestivum L.).

Autophagy, a highly conserved intracellular degradation system, is regarded to be responsible for self-defense and protect cells from abiotic stress. Extensive studies have demonstrated that autophagy plays a crucial role in regulating plant growth and development as well as in response to diverse stresses. However, little is known about autophagy-associated genes (ATGs) in wheat, especially those involved in the regulatory network of stress processes. In this study, a total of 108 putative wheat ATGs (TaATG) were obtained based on a genome-wide search approach. Phylogenetic analysis classified them into 13 subfamilies, of which the TaAtg16 subfamily consisted of 29 members, ranking it the largest subfamily. The conserved motif compositions as well as their exon-intron structures were systematically analyzed and strongly supported the classification. The homoeologous genes tended to have similar gene features during wheat polyploidization. Furthermore, a total of 114 putative cis-elements were found, and those related to hormone, stress, and light responsiveness were abundantly presented in the promoter regions. Co-expression network analysis revealed that orthologous VAMP727 was the hub node of the whole network, and complex interactions were also found. Finally, the expression profiles of TaATGs among different tissues and under abiotic stresses were investigated to identify tissue-specific or stress-responsive candidates, and then 14 were validated by wet-lab analysis. Results showed that the TaAtg8 subfamily played a crucial role in tissue autophagy and stress defense, which could be considered as processes that are candidates for further functional study. This was the first study to comprehensively investigate the ATG family in wheat, which ultimately provided important clues for further functional analysis and also took a step toward uncovering the evolutionary mechanism of ATG genes in wheat and beyond.

Expression of microRNA let-7a positively correlates with hepatitis B virus replication in hepatocellular carcinoma tissues.

Let-7a miRNA is downregulated in various cancers. However, in hepatocellular carcinoma (HCC) patients infected with hepatitis B virus (HBV), the relationship between let-7a and HBV replication has not been fully elucidated. Liver specimens were collected from 23 HCC patients with chronically active HBV. The serum levels of the HBV antigens hepatitis B surface antigen (HBsAg) and hepatitis B virus e antigen (HBeAg), and the HBV antibodies, anti-HBs, anti-HBe and anti-hepatitis B core antigen (anti-HBc) were measured using the microparticle enzyme immunoassay. Let-7a levels and HBV DNA copy numbers were measured by quantitative real-time PCR (qRT-PCR) and analyzed statistically. A let-7a specific antisense oligonucleotide was introduced to the HBV-producing cell line HepG2.2.15 and a change in HBV DNA copy numbers was assessed by qRT-PCR. HCC patients with highly active HBV replication (>106 DNA copies/mL) showed higher levels of serum HBsAg and anti-HBc than patients with less active HBV replication (<103 DNA copies/mL). The level of let-7a was lower in malignant tissues than in adjacent normal tissues. However, patients with highly active HBV replication demonstrated a significantly higher level of let-7a in hepatocarcinoma tissue than patients with less active HBV replication ( P < 0.05). A higher level of let-7a was observed in the HBV-producing cell line HepG2.2.15 than in HepG2 cells ( P < 0.05), and let-7a down-regulation by antisense oligonucleotides led to a reduction in HBV DNA copy numbers ( P < 0.05), indicating a correlation between the let-7a level and HBV replication. Down-regulation of let-7a reduces HBV replication and could prevent the development of HCC, suggesting it could be an effective therapeutic treatment for HBV infection. Impact statement Although interferon and nucleic acid analogues effectively suppress HBV replication in HBV patients, there is no treatment which eradicates the virus. Moreover, the therapeutic effect can be reduced by virus mutations or drug resistance. Let-7a is a miRNA initially found in the nematode as a master regulator of developmental processes, but also exists in humans. It has been reported that the transcription of let-7a was much lower in HCC than in normal liver tissues and specific miRNA could directly promote virus replication. Therefore we hypothesized that transcription of let-7a promotes HBV replication, which might compromise the therapeutic effects of antivirus treatments. In our present study, we demonstrated a correlation between let-7a transcription and HBV replication in surgical specimens obtained from patients with HCC, as well as in HCC cell lines. Our finding might be the base for a new approach to improve HBV infection treatments in the future.

Watt-level mid-infrared radiation via self-seeded difference-frequency generation from a pre-chirp managed femtosecond Yb-fiber amplifier.

We obtained over 1 W average power at ∼3550 nm wavelength via self-seeded difference-frequency generation (DFG) through a 5 cm long periodically poled MgO-doped lithium niobate crystal. The pump and signal sources are derived from the identical pre-chirp managed femtosecond Yb-fiber amplifier with sub-100-fs pulse duration and 84 MHz repetition rate for simple synchronization. This result is believed to be among the highest-average-power, femtosecond mid-infrared radiation obtained via DFG.

De novo Assembly and Characterization of the Transcriptome of Broomcorn Millet (Panicum miliaceum L.) for Gene Discovery and Marker Development.

Broomcorn millet (Panicum miliaceum L.) is one of the world's oldest cultivated cereals, which is well-adapted to extreme environments such as drought, heat, and salinity with an efficient C4 carbon fixation. Discovery and identification of genes involved in these processes will provide valuable information to improve the crop for meeting the challenge of global climate change. However, the lack of genetic resources and genomic information make gene discovery and molecular mechanism studies very difficult. Here, we sequenced and assembled the transcriptome of broomcorn millet using Illumina sequencing technology. After sequencing, a total of 45,406,730 and 51,160,820 clean paired-end reads were obtained for two genotypes Yumi No. 2 and Yumi No. 3. These reads were mixed and then assembled into 113,643 unigenes, with the length ranging from 351 to 15,691 bp, of which 62,543 contings could be assigned to 315 gene ontology (GO) categories. Cluster of orthologous groups and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses assigned could map 15,514 unigenes into 202 KEGG pathways and 51,020 unigenes to 25 COG categories, respectively. Furthermore, 35,216 simple sequence repeats (SSRs) were identified in 27,055 unigene sequences, of which trinucleotides were the most abundant repeat unit, accounting for 66.72% of SSRs. In addition, 292 differentially expressed genes were identified between the two genotypes, which were significantly enriched in 88 GO terms and 12 KEGG pathways. Finally, the expression patterns of four selected transcripts were validated through quantitative reverse transcription polymerase chain reaction analysis. Our study for the first time sequenced and assembled the transcriptome of broomcorn millet, which not only provided a rich sequence resource for gene discovery and marker development in this important crop, but will also facilitate the further investigation of the molecular mechanism of its favored agronomic traits and beyond.