Quantitative profiling of pseudouridylation landscape in the human transcriptome.

Pseudouridine (Ψ) is an abundant post-transcriptional RNA modification in ncRNA and mRNA. However, stoichiometric measurement of individual Ψ sites in human transcriptome remains unaddressed. Here we develop 'PRAISE', via selective chemical labeling of Ψ by bisulfite to induce nucleotide deletion signature during reverse transcription, to realize quantitative assessment of the Ψ landscape in the human transcriptome. Unlike traditional bisulfite treatment, our approach is based on quaternary base mapping and revealed an ~10% median modification level for 2,209 confident Ψ sites in HEK293T cells. By perturbing pseudouridine synthases, we obtained differential mRNA targets of PUS1, PUS7, TRUB1 and DKC1, with TRUB1 targets showing the highest modification stoichiometry. In addition, we quantified known and new Ψ sites in mitochondrial mRNA catalyzed by PUS1. Collectively, we provide a sensitive and convenient method to measure transcriptome-wide Ψ; we envision this quantitative approach would facilitate emerging efforts to elucidate the function and mechanism of mRNA pseudouridylation.

SUN1 inhibits osteogenesis and promotes adipogenesis of human adipose-derived stem cells by regulating α-tubulin and CD36 expression.

Sad and UNC84 domain 1 (SUN1) is a kind of nuclear envelope protein with established involvement in cellular processes, including nuclear motility and meiosis. SUN1 plays an intriguing role in human adipose-derived stem cells (hASCs) differentiation; however, this role remains largely undefined. This study was undertaken to investigate the role of SUN1 in hASCs differentiation, as well as its underlying mechanisms. Employing siRNAs, we selectively downregulated SUN1 and CD36 expression. Microtubules were depolymerized using nocodazole, and PPARγ was activated using rosiglitazone. Western blotting was performed to quantify SUN1, PPARγ, α-tubulin, CD36, OPN, and adiponectin protein expression levels. Alkaline phosphatase and Oil red O staining were used to assess osteogenesis and adipogenesis, respectively. Downregulated SUN1 expression increased osteogenesis and decreased adipogenesis in hASCs, concomitant with upregulated α-tubulin expression and downregulated CD36 expression, alongside reduced nuclear localization of PPARγ. Microtubule depolymerization increased CD36 expression. Rescue experiments indicated that microtubule depolymerization counteracted the downregulated SUN1-induced phenotypic changes. This study demonstrates that SUN1 influences the differentiation of hASCs towards osteogenic and adipogenic lineages, indicating its essential role in cell fate.

Analysis of the Long Non-Coding and Messenger RNA Expression Profiles in the Skin Tissue of Super Merino and Small-Tailed Han Sheep.

Wool quality and yield are two important economic livestock traits. However, there are relatively few molecular studies on lncRNA for improving sheep wool, so these require further exploration. In this study, we examined skin tissue from the upper scapula of Super Merino (SM) and Small-Tailed Han (STH) sheep during the growing period. The apparent difference was verified via histological examination. High-throughput RNA sequencing identified differentially expressed (DE) long non-coding (lncRNAs) and messenger RNAs (mRNAs). The target gene of DE lncRNA and DE genes were enrichment analyzed using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG). A Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR) was used to verify randomly selected DE lncRNAs and mRNAs. Finally, the DE, RAC2, WNT11, and FZD2 genes, which were enriched in the Wnt signaling pathway, were detected via immunohistochemistry. The results showed that a total of 20,888 lncRNAs and 31,579 mRNAs were identified in the skin tissues of the two sheep species. Among these, 56 lncRNAs and 616 mRNAs were differentially expressed. Through qRT-PCR, the trends in the randomly selected DE genes' expression were confirmed to be aligned with the RNA-seq results. GO and KEGG enrichment analysis showed that DE lncRNA target genes were enriched in GO terms as represented by epidermal and skin development and keratin filature and in KEGG terms as represented by PI3K-Akt, Ras, MAPK, and Wnt signaling pathways, which were related to hair follicle growth and development. Finally, immunohistochemistry staining results indicated that RAC2, WNT11, and FZD2 were expressed in dermal papilla (DP). The lncRNAs MSTRG.9225.1 and MSTRG.98769.1 may indirectly participate in the regulation of hair follicle growth, development, and fiber traits by regulating their respective target genes, LOC114113396(KRTAP15-1), FGF1, and IGF1. In addition, MSTRG.84658.1 may regulate the Wnt signaling pathway involved in the development of sheep hair follicles by targeting RAC2. This study provides a theoretical reference for improving sheep breeding in the future and lays a foundation for further research on the effects of MSTRG.84658.1 and the target gene RAC2 on dermal papilla cells (DPC).

Molecular characterization, antibacterial and immunoregulatory activities of liver-expressed antimicrobial peptide 2 in black rockfish, Sebastes schlegelii.

LEAP2 (liver expression antimicrobial peptide 2), is an antimicrobial peptide widely found in vertebrates and mainly expressed in liver. LEAP2 plays a vital role in host innate immunity. In teleosts, a number of LEAP2 homologs have been reported, but their in vivo effects on host defense are still limited. In this study, a LEAP2 homolog (SsLEAP2) was identified from black rockfish, Sebastes schlegelii, and its structure, expression as well as biological functions were analyzed. The results showed that the open reading frame of SsLEAP2 is 300 bp, with a 5'- untranslated region (UTR) of 375 bp and a 3' - UTR of 238 bp. The deduced amino acid sequence of SsLEAP2 shares the highest overall identity (96.97%) with LEAP2 of Sebastes umbrosus. SsLEAP2 possesses conserved LEAP2 features, including a signal peptide sequence, a prodomain and a mature peptide, in which four well-conserved cysteines formed two intrachain disulphide domain. The expression of SsLEAP2 was highest in liver and could be induced by experimental infection with Listonella anguillarum, Edwardsiealla piscicida and Rock bream iridovirus C1 (RBIV-C1). Recombinant SsLEAP2 (rSsLEAP2) purified from Escherichia coli was able to bind with various Gram-positive and Gram-negative bacteria. Further analysis showed that rSsLEAP2 could enhance the respiratory burst activity, and induce the expression of immune genes including interleukin 1-ß (IL-1ß) and serum amyloid A (SAA) in macrophages; additionally, rSsLEAP2 could also promote the proliferation and chemotactic of peripheral blood lymphocytes (PBLs). In vivo experiments indicated that overexpression of SsLEAP2 could inhibit bacterial infection, and increase the expression level of immune genes including IL-1ß, tumor necrosis factor ligand superfamily member 13B (TNF13B) and haptoglobin (HP); conversely, knock down of SsLEAP2 promoted bacterial infection and decreased the expression level of above genes. Taken together, these results suggest that SsLEAP2 is a novel LEAP2 homolog that possesses apparent antibacterial activity and immunoregulatory property, thus plays a critical role in host defense against pathogens invasion.

Biodegradation enhancement of high concentrations formaldehyde waste gas and verification of the metabolic mechanism.

The enhanced effects of formaldehyde biodegradation in a biofilm packing tower are investigated in this study. Three experimental groups were established: a blank control group, a biochar addition group, and a lanthanum addition group. The inlet gas flow rate, the inlet gas concentration, and the structural succession characteristics of the microbial community in the tower were investigated by regular sampling. The intracellular metabolites and key enzymes of the dominant functional bacteria, Pseudomonas P1 and Methylobacterium Q1, in the tower were analyzed. The results indicated that with the biochar addition, the formaldehyde purification efficiency increased significantly from 91.67-94.67 % to 94.12 96.85 %, and the bio-elimination capacity increased with an increase in the inlet gas flow rate from 2.314 to 13.988 mg L-1h-1 to 2.697-15.051 mg L-1h-1. With the addition of lanthanum, the purification efficiency increased significantly from 90.80-93.98 % to 94.36-96.78 %, and the bio-elimination capacity increased with an increase in the inlet gas concentration from 1.099-11.284 mg L-1h-1 to 1.266-11.961 mg L-1h-1. The microbial community structure in the tower changed with system operation, and the formaldehyde degrading functional bacteria formed the dominant bacteria. It was verified that P1 and Q1 metabolized high concentrations of formaldehyde by the serine cycle and the ribulose monophosphate (RuMP) cycle.

[Pseudo-targeted metabolomics for differential components of Rhei Radix et Rhizoma from three plant species].

Rhei Radix et Rhizoma is common traditional Chinese medicine with multiple original plants. The content and proportion of the active components in Rhei Radix et Rhizoma from different plant species were compared to accurately evaluate the medicine qua-lity and provide a theoretical basis for precise use of this medicine in clinical practice. In this study, fresh Rhei Radix et Rhizoma samples were collected from the four-year-old plants of Rheum palmatum, R. tanguticum, and R. officinale. The relative content of 220 anthraquinones, anthrones, and tannins in the samples were determined by pseudo-targeted metabolomics, and the differential components were screened by multivariate statistical methods. The principal component analysis classified the samples into three clusters according to the original plants. The orthogonal partial least squares-discriminant analysis(OPLS-DA) screened out 117 differential components, including 8 free anthraquinones, 18 anthraquinone glycosides, 80 anthrones, and 11 tannins. Twenty-eight components had the highest content in R. tanguticum, mainly including sennosides, anthraquinone glycosides, and procyanidins. Thirty-five components showed the highest content in R. officinale, mainly including free anthraquinones and catechines. Fifty-four components showed the highest content in R. palmatum, mainly including dianthrones, while the structures of most of them cannot be determined temporarily. The content distribution of differential components in the three original plants indicates that R. tanguticum has the strongest effect of purging, while R. officinale has the strongest effect of clearing heat and purging fire, and both have stronger effects of resolvong stasis and dredging meridians than R. palmatum.

Regulation of the integrin αVß3- actin filaments axis in early osteogenic differentiation of human mesenchymal stem cells under cyclic tensile stress.

BACKGROUND: Integrins are closely related to mechanical conduction and play a crucial role in the osteogenesis of human mesenchymal stem cells. Here we wondered whether tensile stress could influence cell differentiation through integrin αVß3. METHODS: We inhibited the function of integrin αVß3 of human mesenchymal stem cells by treating with c(RGDyk). Using cytochalasin D and verteporfin to inhibit polymerization of microfilament and function of nuclear Yes-associated protein (YAP), respectively. For each application, mesenchymal stem cells were loaded by cyclic tensile stress of 10% at 0.5 Hz for 2 h daily. Mesenchymal stem cells were harvested on day 7 post-treatment. Western blotting and quantitative RT-PCR were used to detect the expression of alkaline phosphatase (ALP), RUNX2, ß-actin, integrin αVß3, talin-1, vinculin, FAK, and nuclear YAP. Immunofluorescence staining detected vinculin, actin filaments, and YAP nuclear localization. RESULTS: Cyclic tensile stress could increase the expression of ALP and RUNX2. Inhibition of integrin αVß3 activation led to rearrangement of actin filaments and downregulated the expression of ALP, RUNX2 and promoted YAP nuclear localization. When microfilament polymerization was inhibited, ALP, RUNX2, and nuclear YAP nuclear localization decreased. Inhibition of YAP nuclear localization could reduce the expression of ALP and RUNX2. CONCLUSIONS: Cyclic tensile stress promotes early osteogenesis of human mesenchymal stem cells via the integrin αVß3-actin filaments axis. YAP nuclear localization participates in this process of human mesenchymal stem cells. Video Abstract.

Identification, expression pattern and functional characterization of IFN-γ involved in activating JAK-STAT pathway in Sebastes schlegeli.

IFN-γ (interferon gamma) is a critical cytokine in the immune system involved both directly and indirectly in antiviral activity, stimulation of bactericidal activity, antigen presentation and activation of macrophages via the Janus kinase/signal transducer and activator of transcription (JAK-STAT) pathway. The IFN-γ function is best described in cell defense against intracellular pathogens in mammals, but IFN-γ cytokine-induced metabolic change and its role in anti-infection remain unknown in teleost fish. In this study, a novel IFN-γ (SsIFN-γ) was identified from black rockfish (Sebastes schlegeli) by rapid amplification of cDNA ends (RACE). The open reading frame (ORF) of SsIFN-γ encoded a putative protein of 215 amino acids and shares 60.2%-93.5% overall sequence identities with other teleost IFN-γ. SsIFN-γ was distributed ubiquitously in all the detected tissues and immune cells, which was highly expressed in the spleen, gills, head kidney by quantitative real-time PCR. The mRNA expression of SsIFN-γ was significantly upregulated in the spleen, head kidney, head kidney (HK) macrophages and peripheral blood lymphocytes (PBLs) during pathogen infection. Meanwhile, the recombinant protein (rSsIFN-γ) exhibited an immunomodulatory function to enhance respiratory burst activity and nitric oxide response of HK macrophages. Furthermore, rSsIFN-γ could effectively upregulate the expression of macrophage proinflammatory cytokine, the expression of JAK-STAT signaling pathway related genes and interferon-related downstream genes in the head kidney and spleen. Luciferase assays showed ISRE and GAS activity were obviously enhanced after rSsIFN-γ treatment. These results indicated that SsIFN-γ possessed apparent immunoregulatory properties and played a role in fighting pathogen infection which will be helpful to further understanding of the immunologic mechanism of teleosts IFN-γ in innate immunity.

NKHs27, a sevenband grouper NK-Lysin peptide that possesses immunoregulatory and antimicrobial activity.

As an effective and broad-spectrum antimicrobial peptide, NK-Lysin is attracted more and more attention at present. However, the functions and action mechanism of NK-Lysin peptides are still not comprehensive enough at present. In this study, a sevenband grouper (Hyporthodus septemfasciatus) NK-Lysin peptide, NKHs27, was identified and synthesized, and its biological functions were studied. The results indicated that NKHs27 shares 44.44%∼88.89% overall sequence identities with other teleost NK-Lysin peptides. The following antibacterial activity assay exhibited that NKHs27 was active against both Gram-negative and Gram-positive bacteria, including Staphylococcus aureus, Listonella anguillarum, Vibrio parahaemolyticus and Vibrio vulnificus. Additionally, NKHs27 showed a synergistic effect when it was combined with rifampicin or erythromycin. In the process of interaction with the L. anguillarum cells, NKHs27 changed the cell membrane permeability and retained its morphological integrity, then penetrated into the cytoplasm to act on genomic DNA or total RNA. Then, in vitro studies showed that NKHs27 could enhance the respiratory burst ability of macrophages and upregulate immune-related genes expression in it. Moreover, NKHs27 incubation improved the proliferation of peripheral blood leukocytes significantly. Finally, in vivo studies showed that administration of NKHs27 prior to bacterial infection significantly reduced pathogen dissemination and replication in tissues. In summary, these results provide new insights into the function of NK-Lysin peptides in teleost and support that NKHs27, as a novel broad-spectrum antibacterial peptide, has potential applications in aquaculture against pathogenic infections.

Naringenin facilitates M2 macrophage polarization after myocardial ischemia-reperfusion by promoting nuclear translocation of transcription factor EB and inhibiting the NLRP3 inflammasome pathway.

Myocardial ischemia-reperfusion injury (MIRI) remains an unsolved puzzle in medical circles. Naringenin (NAR) is a flavonoid with cardioprotective potential. The purpose of this article was to discuss the protective mechanism of NAR in MIRI by regulating macrophage polarization. The MIRI mouse model was established and perfused with NAR before surgery. In the in vitro experiment, macrophages RAW264.7 were treated with lipopolysaccharide to induce M1 polarization after pretreatment with NAR. Rescue experiments were carried out to validate the functions of transcription factor EB (TFEB), the NLR pyrin domain containing 3 (NLRP3) inflammasome, and autophagy in macrophage polarization. NAR reduced histopathological injury and infarction of myocardial tissues in MIRI mice, inhibited M1 polarization and promoted M2 polarization of macrophages, diminished levels of pro-inflammatory factors, and augmented levels of anti-inflammatory factors. NAR facilitated TFEB nuclear translocation and inhibited the NLRP3 inflammasome pathway. Silencing TFEB or Nigericin partly nullified the effect of NAR on macrophage polarization. NAR increased autophagosome formation, autophagy flux, and autophagy level. Autophagy inhibitor 3-methyladenine partly invalidated the inhibition of NAR on the NLRP3 inflammasome pathway. In animal experiments, NAR protected MIRI mice through the TFEB-autophagy-NLRP3 inflammasome pathway. Collectively, NAR inhibited NLRP3 inflammasome activation and facilitated M2 macrophage polarization by stimulating TFEB nuclear translocation, thus protecting against MIRI.

A Mid-Infrared Quantum Cascade Laser Ultra-Sensitive Trace Formaldehyde Detection System Based on Improved Dual-Incidence Multipass Gas Cell.

Formaldehyde (HCHO) is a tracer of volatile organic compounds (VOCs), and its concentration has gradually decreased with the reduction in VOC emissions in recent years, which puts forward higher requirements for the detection of trace HCHO. Therefore, a quantum cascade laser (QCL) with a central excitation wavelength of 5.68 µm was applied to detect the trace HCHO under an effective absorption optical pathlength of 67 m. An improved, dual-incidence multi-pass cell, with a simple structure and easy adjustment, was designed to further improve the absorption optical pathlength of the gas. The instrument detection sensitivity of 28 pptv (1σ) was achieved within a 40 s response time. The experimental results show that the developed HCHO detection system is almost unaffected by the cross interference of common atmospheric gases and the change of ambient humidity. Additionally, the instrument was successfully deployed in a field campaign, and it delivered results that correlated well with those of a commercial instrument based on continuous wave cavity ring-down spectroscopy (R2 = 0.967), which indicates that the instrument has a good ability to monitor ambient trace HCHO in unattended continuous operation for long periods of time.

Three-dimensional reconstruction of a leaking gas cloud based on two scanning FTIR remote-sensing imaging systems.

Remote sensing imaging technology is one of the most powerful tools for gas leak monitoring in chemical industrial parks. In the case of leaks, it is necessary to quickly and accurately obtain detailed information of the gas cloud (volume, distribution, diffusion situation and location). This paper proposes a 3-D quantitative reconstruction method for gas clouds. Two scanning Fourier transform infrared (FTIR) remote-sensing imaging systems were used to perform telemetry experiments in a monitored space with a total volume of 314.9 m3, and the released gases were SF6 and CH4. One scanning FTIR remote-sensing imaging system can only measure a 2-D concentration-path-length product (CL) image of a 3-D gas cloud, where each pixel has attitude information of elevation and azimuth. Geometric methods are applied to locate the monitored space and construct a 3-D grid (longitude, latitude, altitude). The optical path length (OPL) sparse matrix of each layer is generated, and the concentration distribution of each layer is reconstructed by the simultaneous algebraic reconstruction technique (SART). The reconstructed results of each layer are stacked into a 3-D gas cloud and displayed on the 3-D Earth software at a set threshold. Three-dimensional leaking gas clouds (CH4, SF6) with geometric information and concentration distribution has been generated through the above processes from measurement, localization to reconstruction and display. On the premise that the gas cloud is completely covered by the field of view of each scanning system, the localization and quantification of the gas cloud is available. Then weighted concentration centers can be calculated from these gas clouds to approximate the leak source. The proposed method effectively extends the online leak monitoring application of the scanning FTIR remote-sensing imaging system.

Antimicrobial and immunoregulatory activities of the derived peptide of a natural killer lysin from black rockfish (Sebastes schlegelii).

Natural killer lysin (NK-lysin) is a small molecule antimicrobial peptide secreted by natural killer cells and T lymphocytes. In this study, we characterized a cDNA sequence encoding an NK-lysin homologue (SsNKL1) from black rockfish, Sebastes schlegelii. The open reading frame (ORF) of SsNKL1 encodes a putative protein of 149 amino acids and shares 44%-87% overall sequence identities with other teleost NK-lysins. SsNKL1 possesses conserved NK-lysin family features, including a signal sequence and a surfactant-associated protein B (SapB) domain, sequence analysis revealed that SsNKL1 is most closely related to false kelpfish (Sebastiscus marmoratus) NK-lysin (with 87% sequence identity). SsNKL1 transcripts were detected in all the tested tissues, with the highest level in the kidney, followed by the spleen and gills. Upon Listonella anguillarum infection, the mRNA expression of SsNKL1 in the black rockfish was significantly up-regulated in the liver and kidney. The derived peptide SsNKLP27 from SsNKL1 was synthesized, and its biological function was studied. SsNKLP27 showed direct antibacterial activity against Gram-negative and Gram-positive bacteria, including Staphylococcus aureus, Bacillus subtilis, L. anguillarum, Vibrio parahaemolyticus, Vibrio alginolyticus and Vibrio vulnificus. SsNKLP27 treatment facilitated the bactericidal process of erythromycin by enhancing the permeability of the outer membrane. In the process of interaction with the target bacterial cells, SsNKLP27 changed the permeability and retained the morphological integrity of the cell membrane, then penetrated into the cytoplasm, and induced the degradation of genomic DNA and total RNA. In vivo studies showed that administration of SsNKLP27 before bacterial and viral infection significantly reduced the transmission and replication of pathogens in tissues. In vitro analysis showed that SsNKLP27 could enhance the respiratory burst ability and regulate the expression of some immune-related genes of macrophages. In summary, these results provided new insights into the function of NK-lysins in teleost fish and support that SsNKLP27 is a new broad-spectrum antimicrobial peptide that has a potential application prospect in aquaculture against pathogenic infection.

Nitric oxide detection using principal component analysis spectral structure matching to the UV derivative spectrum.

Ultraviolet (UV) spectroscopy is widely applied in real-time environmental monitoring, especially in diesel vehicle nitrogen monoxide (NO) emissions. However, in field experiments, UV absorption spectrum may exist for different degrees of drifts. Spectral jitters may exist for various reasons such as optical power variation, electrical signal drift, and the refractive index jitters of the optical path for an extended period of time, which causes the detection system to be calibrated. And the pulse xenon lamps as the UV source are characterized by specific emission lines that interfere in spectral analysis directly. For these problems, we proposed the spectral structure matching method based on principal component analysis (PCA), which was compared with the conventional polynomial fitting method to observe feasibility and variability. Further, the UV derivative spectrum was applied to the system appropriately, due to the variation of the absorption peak, and was only related to the target gas by using the above method. We validated our method experimentally by performing the NO UV detection system with the calibration and the comparison test. The results suggested that the calibration relative error was less than 9% and the measurement relative error was less than 6% for this wide range by the proposed processes, which optimized the interference of spectral structures and fluctuation to the system and therefore provided better monitoring. This study may provide an alternative spectral analysis method that is unaffected on the specific emission lines of lamps and is not limited to the spectral region and the target gas.

Drivers of improved PM2.5 air quality in China from 2013 to 2017.

From 2013 to 2017, with the implementation of the toughest-ever clean air policy in China, significant declines in fine particle (PM2.5) concentrations occurred nationwide. Here we estimate the drivers of the improved PM2.5 air quality and the associated health benefits in China from 2013 to 2017 based on a measure-specific integrated evaluation approach, which combines a bottom-up emission inventory, a chemical transport model, and epidemiological exposure-response functions. The estimated national population-weighted annual mean PM2.5 concentrations decreased from 61.8 (95%CI: 53.3-70.0) to 42.0 µg/m3 (95% CI: 35.7-48.6) in 5 y, with dominant contributions from anthropogenic emission abatements. Although interannual meteorological variations could significantly alter PM2.5 concentrations, the corresponding effects on the 5-y trends were relatively small. The measure-by-measure evaluation indicated that strengthening industrial emission standards (power plants and emission-intensive industrial sectors), upgrades on industrial boilers, phasing out outdated industrial capacities, and promoting clean fuels in the residential sector were major effective measures in reducing PM2.5 pollution and health burdens. These measures were estimated to contribute to 6.6- (95% CI: 5.9-7.1), 4.4- (95% CI: 3.8-4.9), 2.8- (95% CI: 2.5-3.0), and 2.2- (95% CI: 2.0-2.5) µg/m3 declines in the national PM2.5 concentration in 2017, respectively, and further reduced PM2.5-attributable excess deaths by 0.37 million (95% CI: 0.35-0.39), or 92% of the total avoided deaths. Our study confirms the effectiveness of China's recent clean air actions, and the measure-by-measure evaluation provides insights into future clean air policy making in China and in other developing and polluting countries.

Analysis of factors influencing cervical lymph node metastasis of papillary thyroid carcinoma at each lateral level.

OBJECTIVE: To analyze the clinicopathological characteristics of patients with papillary thyroid carcinoma (PTC) and its influence on the distribution of lymph node metastasis at each lateral level of the neck to guide precise treatment of the lateral area. METHODS: The clinicopathological data of patients with PTC initially diagnosed and treated at our hospital from February 2014 to September 2021 were collected; the metastatic status of each lateral level was recorded, and correlations were analyzed. RESULTS: A total of 203 patients were enrolled in this study. There were 67 males and 136 females, with an average age of 41.1 years. In the lateral cervical area, lymph node metastasis was found at level IIa in 81 patients (39.9%); level III, 171 patients (84.2%); level IV, 122 patients (60%); and level Vb, 18 patients (8.9%). Correlation analysis showed that age (r = 0.198, P < 0.01) and sex (r = 0.196, P < 0.01) were weakly correlated with the number of positive lymph nodes in the central region. The tumor size (r = 0.164, P < 0.05) was weakly correlated with lymph node metastasis at level IV. The presence of multiple tumor foci was weakly correlated with lymph node metastasis at level IIa (r = 0.163, P < 0.05) and Vb (r = 0.143, P < 0.05). The tumor location (r = - 0.168, P < 0.05) was weakly correlated with lymph node metastasis at level III. The number of positive lymph nodes in the central region (r = 0.189, P < 0.01) was weakly correlated with lymph node metastasis at level IV. Binary logistic regression analysis showed that the risk of metastasis of multifocal tumors was higher than that of unifocal tumors by 1.958 times at level IIa (P = 0.021, OR = 1.958) and 2.929 times at level Vb (P = 0.049, OR = 2.929). The higher the tumor was located, the higher the risk of metastasis at level III (P = 0.014, OR = 0.563). Every additional positive lymph node in the central region increased the risk of metastasis at level IV by 1.126 times (P = 0.009, OR = 1.126). CONCLUSIONS: For patients with pathological evidence of lateral metastasis, standard dissection of level IIa through Vb is recommended; selective dissection requires careful consideration. Patients with multifocal tumors have a high risk of metastasis at levels IIa and Vb, which requires special attention during the operation.

Distribution and transport characteristics of fine particulate matter in beijing with mobile lidar measurements from 2015 to 2018.

Accurately quantifying the concentration and transport flux of atmospheric fine particulate matter (PM2.5) is vital when attempting to thoroughly identify the pollution formation mechanism. In this study, the mobile lidar measurements in Beijing on heavily polluted days in December from 2015 to 2018 are presented. The lidar was mounted on a vehicle, which could perform measurements along designated routes. On the basis of mobile lidar measurements along closed circuits of the 6th Ring Road around Beijing, the spatial distribution and transport flux of PM2.5 in Beijing were determined with information of wind field. In the spatial distribution, both the concentration and transport of PM2.5 were revealed to be more significant in the southern section of Beijing. The regional transport layer at heights < 1.3 km plays an important role in pollution formation. The maximum transport flux reached 1600 µg/(m2*sec) on 11 December 2016. With the aerosol boundary layer height determined from the image edge detection (IED) method, the inter-annual variations of the aerosol boundary layer height (ABLH) were also analysed. The ABLH decreased from 0.73 to 0.46 km during the same heavy pollution period from 2015 to 2018. Increasingly adverse aerosol boundary layer (ABL) meteorological factors, including lower ABLH, light winds, temperature inversions, and accumulated moisture, have become necessary for pollution formation in Beijing.

Nocturnal atmospheric chemistry of NO3 and N2O5 over Changzhou in the Yangtze River Delta in China.

Comprehensive observations of the nocturnal atmospheric oxidation of NO3 and N2O5 were conducted at a suburban site in Changzhou in the YRD using cavity ring-down spectroscopy (CRDS) from 27 May to 24 June, 2019. High concentrations of NO3 precursors were observed, and the nocturnal production rate of NO3 was determined to be 1.7 ± 1.2 ppbv/hr. However, the nighttime NO3 and N2O5 concentrations were relatively low, with maximum values of 17.7 and 304.7 pptv, respectively, illustrating the rapid loss of NO3 and N2O5. It was found that NO3 dominated the nighttime atmospheric oxidation, accounting for 50.7%, while O3 and OH only contributed 34.1% and 15.2%, respectively. For the reactions of NO3 with volatile organic compounds (VOCs), styrene was found to account for 60.3%, highlighting its dominant role in the NO3 reactivity. In general, the contributions of the reactions between NO3 and VOCs and the N2O5 uptake to NO3 loss were found to be about 39.5% and 60.5%, respectively, indicating that N2O5 uptake also played an important role in the loss of NO3 and N2O5, especially under the high humidity conditions in China. The formation of nitrate at night mainly originated from N2O5 uptake, and the maximum production rate of NO3- reached 6.5 ppbv/hr. The average NOx consumption rate via NO3 and N2O5 chemistry was found to be 0.4 ppbv/h, accounting for 47.9% of the total NOx removal. The predominant roles of NO3 and N2O5 in nitrate formation and NOx removal in the YRD region was highlighted in this study.

Measurement of HONO flux using the aerodynamic gradient method over an agricultural field in the Huaihe River Basin, China.

To investigate nitrous acid (HONO) levels and potential HONO sources above crop rotation fields. The HONO fluxes were measured by the aerodynamic gradient (AG) method from 14 December 2019 to 2 January 2020 over an agricultural field in the Huaihe River Basin. The ambient HONO levels were measured at two different heights (0.15 and 1.5 m), showing a typical diurnal cycle with low daytime levels and high nighttime levels. The upward HONO fluxes were mostly observed during the day, whereas deposition dominated at night. The diurnal variation of HONO flux followed solar radiation, with a noontime maximum of 0.2 nmol/(m2∙sec). The average upward HONO flux of 0.06 ± 0.17 nmol/(m2∙sec) indicated that the agricultural field was a net source for atmospheric HONO. The higher HONO/NO2 ratio and NO2-to-HONO conversion rate close to the surface suggested that nocturnal HONO was formed and released near the ground. The unknown HONO source was derived from the daytime HONO budget analysis, with an average strength of 0.31 ppbV/hr at noontime. The surface HONO flux, which was highly correlated with the photolysis frequency J(NO2) (R2 = 0.925) and the product of J(NO2) × NO2 (R2 = 0.840), accounted for ∼23% of unknown daytime HONO source. The significant correlation between HONO fluxes and J(NO2) suggests a light-driven HONO formation mechanism responsible for the surface HONO flux during daytime.

PAX7 promotes CD49f-positive dairy goat spermatogonial stem cells' self-renewal.

Spermatogenesis is a complex process that originates from and depends on the spermatogonial stem cells (SSCs). The number of SSCs is rare, which makes the separation and enrichment of SSCs difficult and inefficient. The transcription factor PAX7 maintains fertility in normal spermatogenesis in mice. However, for large animals, much less is known about the SSCs' self-renewal regulation, especially in dairy goats. We isolated and enriched the CD49f-positive and negative dairy goat testicular cells by magnetic-activated cell sorting strategies. The RNA- sequencing and experimental data revealed that cells with a high CD49f and PAX7 expression are undifferentiated spermatogonia in goat testis. Our findings indicated that ZBTB16 (PLZF), PAX7, LIN28A, BMPR1B, FGFR1, and FOXO1 were expressed higher in CD49f-positive cells as compared to negative cells and goat fibroblasts cells. The expression and distribution of PAX7 in dairy goat also have been detected, which gradually decreased in testis tissue along with the increasing age. When the PAX7 gene was overexpressed in dairy goat immortal mGSCs-I-SB germ cell lines, the expression of PLZF, GFRα1, ID4, and OCT4 was upregulated. Together, our data demonstrated that there is a subset of spermatogonial stem cells with a high expression of PAX7 among the CD49f+ spermatogonia, and PAX7 can maintain the self-renewal of CD49f-positive SSCs.