Promiscuous Oxidosqualene Cyclases from Neoalsomitra integrifoliola Catalyzing the Formation of Tetracyclic, Pentacyclic, and Heterocyclic Triterpenes

Six oxidosqualene cyclases (NiOSC1-NiOSC6) from Neoalsomitra integrifoliola were characterized for the biosynthesis of diverse triterpene scaffolds, including tetracyclic and pentacyclic triterpenes from the 2,3-oxidosqualene (1) and oxacyclic triterpenes from the 2,3:22,23-dioxidosqualene (2). NiOSC1 showed high efficiency in the production of naturally rare (20R)-epimers of oxacyclic triterpenes. Mutagenesis results revealed that the NiOSC1-F731G mutant significantly increased the yields of (20R)-epimers compared to the wild type. Homology modeling and molecular docking elucidated the origin of the (20R)-configuration in the epoxide addition step.

Development of a stable genetic transformation system in Erigeron breviscapus: a case study with EbYUC2 in relation to leaf number and flowering time

MAIN CONCLUSION

A stable genetic transformation system for Erigeron breviscapus was developed. We cloned the EbYUC2 gene and genetically transformed it into Arabidopsis thaliana and E. breviscapus. The leaf number, YUC2 gene expression, and the endogenous auxin content in transgenic plants were significantly increased. Erigeron breviscapus is a prescription drug for the clinical treatment of cardiovascular and cerebrovascular diseases. The rosette leaves have the highest content of the major active compound scutellarin and are an important component in the yield of E. breviscapus. However, little is known about the genes related to the leaf number and flowering time of E. breviscapus. In our previous study, we identified three candidate genes related to the leaf number and flowering of E. breviscapus by combining resequencing data and genome-wide association study (GWAS). However, their specific functions remain to be characterized. In this study, we cloned and transformed the previously identified full-length EbYUC2 gene into Arabidopsis thaliana, developed the first stable genetic transformation system for E. breviscapus, and obtained the transgenic plants overexpressing EbYUC2. Compared with wild-type plants, the transgenic plants showed a significant increase in the number of leaves, which was correlated with the increased expression of EbYUC2. Consistently, the endogenous auxin content, particularly indole-3-acetic acid, in transgenic plants was also significantly increased. These results suggest that EbYUC2 may control the leaf number by regulating auxin biosynthesis, thereby laying a foundation for revealing the molecular mechanism governing the leaf number and flowering time of E. breviscapus.

Functional characterization of genes related to triterpene and flavonoid biosynthesis in Cyclocarya paliurus

MAIN CONCLUSION

The oxidosqualene cyclases (OSCs) generating triterpenoid skeletons in Cyclocarya paliurus were identified for the first time, and two uridine diphosphate (UDP)-glycosyltransferases (UGTs) catalyzing the glycosylation of flavonoids were characterized. Cyclocarya paliurus, a native rare dicotyledonous plant in China, contains an abundance of triterpenoid saponins and flavonoid glycosides that exhibit valuable pharmaceutical effects in preventing hypertension, hyperlipidemia, and diabetes. However, the molecular mechanism explaining the biosynthesis of triterpenoid saponin and flavonoid glycoside in C. paliurus remains unclear. In this study, the triterpene content in different tissues and the expression pattern of genes encoding the key enzymes associated with triterpenoid saponin and flavonoid glycoside biosynthesis were studied using transcriptome and metabolome analysis. The eight upstream oxidosqualene cyclases (OSCs) involved in triterpenoid saponin biosynthesis were functionally characterized, among them CpalOSC6 catalyzed 2,3;22,23-dioxidosqualene to form 3-epicabraleadiol; CpalOSC8 cyclized 2,3-oxidosqualene to generate dammarenediol-II; CpalOSC2 and CpalOSC3 produced β-amyrin and CpalOSC4 produced cycloartenol, while CpalOSC2-CpalOSC5, CpalOSC7, and CpalOSC8 all produced lanosterol. However, no catalytic product was detected for CpalOSC1. Moreover, two downstream flavonoid uridine diphosphate (UDP)-glycosyltransferases (UGTs) (CpalUGT015 and CpalUGT100) that catalyze the last step of flavonoid glycoside biosynthesis were functionally elucidated. These results uncovered the key genes involved in the biosynthesis of triterpenoid saponins and flavonoid glycosides in C. paliurus that could be applied to produce flavonoid glycosides and key triterpenoid saponins in the future via a synthetic strategy.

Biosynthetic pathway of prescription bergenin from Bergenia purpurascens and Ardisia japonica

Bergenin is a typical carbon glycoside and the primary active ingredient in antitussive drugs widely prescribed for central cough inhibition in China. The bergenin extraction industry relies on the medicinal plant species Bergenia purpurascens and Ardisia japonica as their resources. However, the bergenin biosynthetic pathway in plants remains elusive. In this study, we functionally characterized a shikimate dehydrogenase (SDH), two O-methyltransferases (OMTs), and a C-glycosyltransferase (CGT) involved in bergenin synthesis through bioinformatics analysis, heterologous expression, and enzymatic characterization. We found that BpSDH2 catalyzes the two-step dehydrogenation process of shikimic acid to form gallic acid (GA). BpOMT1 and AjOMT1 facilitate the methylation reaction at the 4-OH position of GA, resulting in the formation of 4-O-methyl gallic acid (4-O-Me-GA). AjCGT1 transfers a glucose moiety to C-2 to generate 2-Glucosyl-4-O-methyl gallic acid (2-Glucosyl-4-O-Me-GA). Bergenin production ultimately occurs in acidic conditions or via dehydration catalyzed by plant dehydratases following a ring-closure reaction. This study for the first time uncovered the biosynthetic pathway of bergenin, paving the way to rational production of bergenin in cell factories via synthetic biology strategies.

[Prevalence and influencing factors of abnormal spinal curvature in primary and secondary school students in Shandong Province in 2020]

In 2020, the prevalence of abnormal spinal curvature among 54 079 students in Shandong Province was 1.54%. The multivariate logistic regression model analysis showed that, compared with those in primary school, economically underdeveloped areas, and non-residential schools, students in middle and high schools, economically average areas, and residential schools had a higher risk of abnormal spinal curvature, with OR (95%CI) values of 2.029 (1.662-2.476), 2.746 (2.208-3.416), 2.237 (1.740-2.875) and 2.057 (1.705-2.483), respectively. Compared with those in economically underdeveloped areas, who were underweight, who had seat adjustments≤1 time per academic year, and who had physical education classes≤1 per week, students in economically developed areas, who were normal weight, overweight, and obese, who had seat adjustments≥2 times per academic year, and who had physical education classes 2-3 or≥4 per week, had a lower risk of abnormal spinal curvature, with OR (95%CI) values of 0.690 (0.521-0.915), 0.722 (0.546-0.955), 0.535 (0.389-0.735), 0.383 (0.274-0.535), 0.835 (0.711-0.980), 0.561 (0.474-0.663) and 0.491 (0.315-0.766), respectively.

Maternal Prenatal Factors and Child Adiposity in Associations with Cardiometabolic Risk Factors in Term-Born Chinese Children at the Age of 2 Years

Early growth has long-lasting associations with adult metabolic health. However, the association of adiposity with cardiometabolic risk factors in toddlers remains poorly understood. This study aimed to examine the association of maternal prenatal factors and child adiposity with child cardiometabolic risk factors among boys and girls aged 2 years. This was a birth cohort study of 549 term-born children in Shanghai, China, with follow-up data at the age of 2-years. Child anthropometric and adiposity measurements included weight, length, and skinfold thickness (triceps, subscapular, and abdominal). Child cardiometabolic risk factors included random morning plasma glucose, serum insulin, lipids, and systolic and diastolic blood pressure (SBP, DBP). At 2 years, overweight/obesity (weight-for-length z score, ZWFL > 2) was associated with 12.6 (95%CI 7.7, 17.4) mmHg higher SBP, and 7.9 (4.1, 11.8) mmHg higher DBP in boys, with similar results observed in girls. Maternal hypertensive disorders of pregnancy were associated with 3.0 (0.1, 5.8) higher SBP, 3.17 (0.90, 5.44) mmHg higher DBP, 0.24 (0.01,0.47) mmol/L higher plasma glucose, and 0.26 (0.01,0.51) mmol/L higher serum triglycerides after adjustment for child age, sex, and ZWFL. Maternal hypertensive disorders of pregnancy and child overweight/obesity were associated with higher SBP and DBP at the age of 2 years.

Mixed exposure effect of seminal metals on semen quality, mediation of total antioxidant capacity, and moderation of GSTM1/GSTT1 gene deletion in Chinese reproductive-aged men

BACKGROUND

The effects of metal exposure on semen quality and the role of oxidative damage in this process remain unclear.

METHODS

We recruited 825 Chinese male volunteers, and 12 seminal metals (Mn, Cu, Zn, Se, Ni, Cd, Pb, Co, Ag, Ba, Tl, and Fe), the total antioxidant capacity (TAC), and reduced glutathione were measured. Semen parameters and GSTM1/GSTT1-null genotypes were also detected. Bayesian kernel machine regression (BKMR) was applied to evaluate the effect of the mixed exposure to metals on semen parameters. The mediation of TAC and moderation of GSTM1/GSTT1 deletion were analyzed.

RESULTS

Most seminal metal concentrations were correlated with each other. The BKMR models revealed a negative association between the semen volume and metal mixture, with Cd (cPIP = 0.60) and Mn (cPIP = 0.10) as the major contributors. Compared to fixing all scaled metals at their median value (50th percentiles), fixing the scaled metals at their 75th percentiles decreased the TAC by 2.17 units (95%CI: -2.60, -1.75). Mediation analysis indicated that Mn decreased the semen volume, with 27.82% of this association mediated by TAC. Both the BKMR and multi-linear models showed that seminal Ni was negatively correlated with sperm concentration, total sperm count, and progressive motility, which was modified by GSTM1/GSTT1. Furthermore, Ni and the total sperm count showed a negative association in GSTT1 and GSTM1 null males (β[95%CI]: 0.328 [-0.521, -0.136]) but not in males with GSTT1 and/or GSTM1. Although Fe and the sperm concentration and total sperm count were positively correlated, they showed inverse "U" shapes in univariate analysis.

CONCLUSION

Exposure to the 12 metals was negatively associated with semen volume, with Cd and Mn as the major contributors. TAC may mediate this process. GSTT1 and GSTM1 can modify the reduction in the total sperm count caused by seminal Ni exposure.

[Effects and clinical significance of NLRP3 inflammasome activated by IL-17A in CRSwNP]

Objective: To investigate the effects and clinical significance of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activated by interleukin (IL)-17A in chronic rhinosinusitis with nasal polyps (CRSwNP). Methods: Patients underwent nasal endoscopic surgery in the Third Affiliated Hospital of Sun Yat-sen University from January 2020 to December 2021 were collected, including 28 CRSwNP (including 19 males and 9 females, aged 19 to 67 years), 22 chronic rhinosinusitis without nasal polyps (CRSsNP) and 22 controls. qRT-PCR was used to detect the expressions of IL-17A, NLRP3, IL-1β and IL-18 in the three groups, and their correlations were analyzed. The positions of IL-17A, NLRP3 and IL-18 in nasal polys were analyzed by immunofluorescence. Western Blotting and ELISA were employed to detect the expression of NLRP3, IL-1β and IL-18 in the human nasal epithelial cells after using IL-17A stimulation or IL-17A receptor inhibitor. Immunofluorescence was used to observe the NLRP3, IL-1β, and IL-18 protein expression after IL-17A stimulating human nasal epithelial cells, and after the use of IL-17A receptor inhibitor and NLRP3 inhibitor MCC950. The correlations between NLRP3, IL-1β, IL-18 and CT scores, nasal endoscopic scores, visual analogue scale (VAS) scores, and sino-nasal outcome test (SNOT) 22 scores of CRSwNP patients were analyzed. SPSS 20.0 software was used for statistical analysis. Results: The expressions of IL-17A, NLRP3, IL-1β and IL-18 in the tissues of CRSwNP patients were significantly higher than those in CRSsNP group(P=0.018,P<0.001,P=0.005, P=0.016) and the control group(all P<0.001). IL-17A was positively correlated with the expression of NLRP3, IL-1β, and IL-18(r ralue was 0.643,0.650,0.629,respectively, all P<0.05). IL-17A, NLRP3, and IL-18 were co-localized in the epithelial propria of polyp tissue. IL-17A stimulated the expressions of NLRP3, IL-1β, and IL-18 in human nasal epithelial cells. After the use of IL-17A receptor inhibitor, the expressions of NLRP3, IL-1β, and IL-18 were significantly down-regulated. After the use of NLRP3 inhibitor MCC950, IL-17A was significantly down-regulated to promote the expression of NLRP3, IL-1β, and IL-18. The expressions of NLRP3, IL-1β and IL-18 were positively correlated with CT, nasal endoscopy, VAS, and SNOT22 scores in patients with CRSwNP. Conclusions: IL-17A promotes the release of IL-1β and IL-18 by activating the NLRP3 inflammasome and aggravates the severity of the disease in CRSwNP.

[Application of ulnar nerve diameter changes examined by HRUS in patients with cubital tunnel syndrome]

OBJECTIVE

To evaluate the value of high-resolution ultrasound the diagnosis and prognosis of cubital tunnel syndrome.

METHODS

From January 2018 to June 2019, 47 patients with cubital tunnel syndrome were treated with ulnar nerve release and anterior subcutaneous transposition. There were 41 males and 6 females, aged from 27 to 73 years old. There were 31 cases on the right, 15 cases on the left, and 1 case on both sides. The diameter of ulnar nerve was measured by high-resolution ultrasound pre-and post-operatively, and measured directly during the operation. The recovery status of the patients was evaluated by the trial standard of ulnar nerve function assessment, and the satisfaction of the patients was assessed.

RESULTS

All the 47 cases were followed up for an average of 12 months and the incisions healed well. The diameter of ulnar nerve at the compression level was (0.16±0.04) cm pre-operatively, and the diameter of ulnar nerve was (0.23±0.04) cm post-operatively. The evaluation of ulnar nerve function:excellent in 16 cases, good in 18 cases and fair in 13 cases. Twelve months post-operatively, 28 patients were satisfied, 10 patients were general and 9 patients were dissatisfied.

CONCLUSION

The preoperative examination of ulnar nerve by high-resolution ultrasound is consistent with the intuitive measurement during operation, and the result of postoperative examination of ulnar nerve by high-resolution ultrasound is consistent with follow-up results. High-resolution ultrasound is an effective auxiliary method for the diagnosis and treatment of cubital tunnel syndrome.

Cord blood fatty acid binding protein 4 and lipids in infants born small- or large-for-gestational-age

Aim

Adverse (poor or excessive) fetal growth "programs" an elevated risk of type 2 diabetes. Fatty acid binding protein 4 (FABP4) has been implicated in regulating insulin sensitivity and lipid metabolism relevant to fetal growth. We sought to determine whether FABP4 is associated with poor or excessive fetal growth and fetal lipids.

Methods

In a nested case-control study in the Shanghai Birth Cohort including 60 trios of small-for-gestational-age (SGA, an indicator of poor fetal growth), large-for-gestational-age (LGA, an indicator of excessive fetal growth) and optimal-for-gestational-age (OGA, control) infants, we measured cord blood concentrations of FABP4 and lipids [high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterols, triglycerides (TG)].

Results

Adjusting for maternal and neonatal characteristics, higher cord blood FABP4 concentrations were associated with a lower odds of SGA [OR = 0.29 (0.11-0.77) per log unit increment in FABP4, P = 0.01], but were not associated with LGA (P = 0.46). Cord blood FABP4 was positively correlated with both LDL (r = 0.29, P = 0.025) and HDL (r = 0.33, P = 0.01) in LGA infants only.

Conclusion

FABP4 was inversely associated with the risk of SGA. The study is the first to demonstrate LGA-specific positive correlations of cord blood FABP4 with HDL and LDL cholesterols, suggesting a role of FABP4 in fetal lipid metabolism in subjects with excessive fetal growth.

Site-directed mutagenesis identified the key active site residues of 2,3-oxidosqualene cyclase HcOSC6 responsible for cucurbitacins biosynthesis in Hemsleya chinensis

Hemsleya chinensis is a Chinese traditional medicinal plant, containing cucurbitacin IIa (CuIIa) and cucurbitacin IIb (CuIIb), both of which have a wide range of pharmacological effects, including antiallergic, anti-inflammatory, and anticancer properties. However, few studies have been explored on the key enzymes that are involved in cucurbitacins biosynthesis in H. chinensis. Oxidosqualene cyclase (OSC) is a vital enzyme for cyclizing 2,3-oxidosqualene and its analogues. Here, a gene encoding the oxidosqualene cyclase of H. chinensis (HcOSC6), catalyzing to produce cucurbitadienol, was used as a template of mutagenesis. With the assistance of AlphaFold2 and molecular docking, we have proposed for the first time to our knowledge the 3D structure of HcOSC6 and its binding features to 2,3-oxidosqualene. Mutagenesis experiments on HcOSC6 generated seventeen different single-point mutants, showing that single-residue changes could affect its activity. Three key amino acid residues of HcOSC6, E246, M261 and D490, were identified as a prominent role in controlling cyclization ability. Our findings not only comprehensively characterize three key residues that are potentially useful for producing cucurbitacins, but also provide insights into the significant role they could play in metabolic engineering.

Multiomics analysis of the mechanisms behind flavonoid differences between purple and green tender shoots of Camellia sinensis var. assamica

Flavonoids are rich in tea plants (Camellia sinensis), and responsible for the flavor and healthful benefits of tea beverage. The anthocyanin levels in the purple tender shoots are higher than in the general green leaves of tea plant, which provide special materials to search metabolic mechanisms of flavonoid enrichment in plant. In this work, flavonoid differences between purple and green shoots from tea cultivars "Zijuan" (ZJ) and "Yunkang10" (YK-10) were investigated through metabolomic analysis, and mechanisms for their difference were surveyed by comparative transcriptomic and proteomic analysis. Levels of 34 flavonoids were different between ZJ and YK-10 shoots. Among them, 8 and 6 were marker metabolites in ZJ and YK-10, respectively. The differentially expressed genes (DEGs), differentially expressed proteins (DEPs), and different-level metabolites (DLMs) between ZJ and YK-10 were researched, respectively; and interactions including DEG-DLM, DEP-DLM, DEG-DEP, and DEG-DEP-DLM were analyzed; the contents of 18 characteristic flavonoids in tea leaves and expressions of 34 flavonoid metabolic genes were measured to verify the omics results. Integrated above analyses, a proposed model of flavonoids biosynthesis in tea shoots were established. The differential expression of the leucoanthocyanidin reductase (LAR), anthocyanidin synthase (ANS), anthocyanidin reductase (ANR), UDPG-flavonoid glucosyltransferase (UGT) 75L12 and 94P1 at gene level, and the ANS, ANR, and UGT78A15 at protein level, were closely associated with differences in flavonoids between ZJ and YK-10 shoot. Together, this study provides new information on the flavonoid accumulation mechanism in tea plant.

[The expression profile and potential regulatory mechanism of ACE2 in chronic rhinosinusitis with nasal polyps]

Objective: To preliminarily analyze the expression of angiotensin-converting enzyme 2 (ACE2) and to investigate its potential regulatory mechanism in chronic rhinosinusitis with nasal polyps (CRSwNP). Methods: Patients underwent nasal endoscopic surgery in the Third Affiliated Hospital of Sun Yat-sen University from February 2020 to May 2021 were selected, including 17 males and 6 females, aging from 23 to 66 years old. Expression of ACE2 was evaluated via immunohistochemical staining in controls with non-chronic rhinosinusitis, non-eosinophilic CRSwNP (non-ECRSwNP), and eosinophilic CRSwNP (ECRSwNP) tissue, respectively. Correlations between ACE2 and the indicated Th1/Th2-related cytokines (IFN-γ, IL-4, IL-5, IL-13, IL-25, IL-33, TSLP and periostin) were analyzed based on GSE72713 dataset. Protein-protein interaction (PPI) network was constructed via string database, immune infiltration of GSE72713 dataset was evaluated using cibersort algorithm. ACE2 was comprehensively analyzed by microRNA regulatory network, gene set enrichment analysis (GSEA) and pharmacological analysis. Statistical analysis was performed using GraphPad 7.0 and SPSS 20.0 software. Results: ACE2 was up-regulated in non-ECRSwNP compared with ECRSwNP. Microarray analysis showed that ACE2 was positively correlated with IFN-γ while inversely correlated with IL-5, IL-13 and periostin significantly. Analysis of immune infiltration suggested that ACE2 expression correlated positively with the number of M1 macrophage while negatively with M2 macrophage. GSEA demonstrated that interferon-related signaling pathways were up-regulated in non-ECRSwNP, and miRNA-200B/miRNA-200C/miRNA-429 pathways targeting ACE2 were enriched in ECRSwNP. Results of pharmacological analysis indicated that ampicillin was able to promote the expression of ACE2 whereas acetaminophen could down regulated the expression of ACE2. Conclusion: Expression pattern of ACE2 is varied in non-ECRSwNP and ECRSwNP, which may be related to the different infiltration of indicated cytokines and different regulatory pathways of miRNA.

Identifying the dose response relationship between seminal metal at low levels and semen quality using restricted cubic spline function

Environmental exposure to metals, including essential and nonessential elements, may be related to semen quality. Our goal was to explore the continuous relationship between seminal metals and sperm parameters. A restricted cubic spline (RCS) was applied to automatic selection criteria to ascertain the optimal smoothing degree. We recruited 841 male volunteers from Henan Province, China. Eighteen seminal metals, namely Al, Cr, Mn, Cu, Zn, Se, As, Ni, Cd, Pb, Co, V, Rb, Ag, Ba, TI, Fe, and Li, and 21 semen parameters were detected. Seminal malondialdehyde (MDA) was also detected to express oxidative stress. We revealed a non-linear relationship of the vanadium and chromium exposure to semen parameters. There were inverse 'U' shapes found between seminal Cr and sperm concentrations, total sperm count, and semen quality. The best semen quality was observed when the seminal Cr concentration was 5.05 ppb, and an increase or decrease in chromium concentration led to decreased semen quality. The V concentration was associated with reduced sperm concentration, total sperm count, normal morphology, and progressive motility at high doses (V > 0.58 ppb). Seminal MDA had a strong adverse association with sperm motility parameters, such as curve line velocity (VCL) (P < 0.001), straight line velocity (VSL) (P = 0.004), velocity of average path (VAP) (P < 0.001), and lateral head movement (ALH) (P = 0.001), whereas it was adversely associated with seminal Zn (β [95% confidence interval (CI)], -0.28(-0.41-0.16), P < 0.001) after adjusting for confounding factors. Our findings represent the curves of the dose-response relationship between seminal Cr, seminal V, and semen quality, in which seminal MDA was a good indicator of sperm movement. These models provide new insight into the dose-relationship between metal exposure and semen quality, and further investigation is needed to validate this.

[Liver manifestation of circulatory disorders]

The liver is abundant in blood supply and receives 25% of the cardiac output via the hepatic artery and portal vein. Circulatory disorders may cause hepatic injury, resulting in congestive hepatopathy(CH) and ischemic hepatitis(IH). Hepatic congestion arising from increased hepatic venous pressure and decreased cardiac output is the common pathophysiological basis of both CH and IH. In addition, extensive arteriovenous shunts affect portal pressure and cardiac function, leading to alterations of hepatic blood supply. The current review summarizes the pathophysiology, clinical manifestations and therapeutic interventions of the above diseases, in order to provide reference for clinical practice.

[Expression of CD8+Treg cells in chronic rhinosinusitis and its correlation with eosinophilic infiltration]

Objective: To detect the percentages of CD8⁺Treg cells in the nasal mucosa and peripheral blood of chronic rhinosinusitis (CRS) and to explore their correlation with eosinophilic infiltration. Methods: Thirty-three chronic rhinosinusitis with polyp (CRSwNP), 26 chronic rhinosinusitis without polyp (CRSsNP) and 27 control patients who were collected with the nose mucosal tissue and peripheral blood in the Third Affiliated Hospital of Sun Yat-sen University from March 2017 to October 2018 were selected, including 59 males and 27 females, aging from 18 to 72 years. Hematoxylin and eosin (HE) staining was used to observe the number of eosinophils in the nasal tissues and to classify the CRS into eosinophilic CRS (ECRS) and non-eosinophilic CRS (Non-ECRS). Flow cytometry was used to detect the percentages of CD4⁺ and CD8⁺T cells in lymphocytes of nasal mucosa and peripheral blood. The percentages of CD8⁺Foxp3⁺Treg cells, CD8⁺Foxp3^-IL-10⁺Treg cells, CD8⁺IFN-γ⁺T cells (Tc1), CD8⁺IL-4⁺T cells (Tc2) and CD8⁺IL-17A⁺T cells (Tc17) in lymphocytes of nasal mucosa and peripheral blood were also tested. Besides, the percentages of Foxp3⁺TGF-β⁺Treg cells and Foxp3⁺IL-10⁺Treg cells in CD8⁺T cells were determined. All data were represented by M (IQR). GraphPad 7.0 and SPSS 16.0 were used for illustration and statistical analysis. Results: The percentage of CD8⁺T cells (37.75%(17.35%)) was higher than that of CD4⁺T cells (4.72%(4.29%)) in nasal mucosa (Z=-5.70, P<0.001), while lower (23.60%(9.33%)) than that of CD4⁺T cells (44.05% (10.93%)) in peripheral blood (t=9.72, P<0.001). CRSwNP patients possessed the highest Tc2 (1.82% (1.22%)) and Tc17 (1.93% (2.32%)) percentages than CRSsNP (Tc2: 0.84% (0.79%); Tc17: 0.54% (1.04%)) and control (Tc2: 1.09% (0.92%); Tc17: 0.47% (0.51%), both P<0.05) patients. While, CRSwNP patients possessed the lowest CD8⁺Foxp3⁺Treg cells percentage (0.10% (0.32%)) than CRSsNP (0.43% (1.45%)) and control (0.48% (0.83%), Z value was -2.24, -2.22, respectively, P value was 0.025, 0.027, respectively). The percentages of Foxp3⁺TGF-β⁺Treg cells and Foxp3⁺IL-10⁺Treg cells of CD8⁺T cells in nasal mucosa in CRSwNP were also lower than controls (Z value was 1.46, 0.49, respectively, both P=0.001). Moreover, the percentage of CD8⁺Foxp3^-IL-10⁺Treg cells of CD8⁺T cells was decreased in nasal mucosa of CRSwNP patients (0.14% (0.28%)) when compared with that of CRSsNP (0.89% (0.81%), Z=0.61, P=0.03). ECRS patients had the lower percentages of CD8⁺Foxp3⁺Treg cells (0.07% (0.44%)) and CD8⁺Foxp3^-IL-10⁺Treg cells (0.13% (0.21%)) than Non-ECRS patients (CD8⁺Foxp3⁺Treg cells: 0.53% (0.75%); CD8⁺Foxp3^-IL-10⁺Treg cells: 0.29% (0.76%), t value was 2.14, 2.78, respectively, both P<0.05). The percentage of CD8⁺Foxp3⁺Treg cells and the ratio of CD8⁺Foxp3^-IL-10⁺T per CD8⁺T cells were negatively correlated with the percentage of eosinophils in CRS patients(R² value was 0.56, 0.78, respectively, both P<0.001). There was no significant difference in the distribution of CD8⁺Fxop3⁺Treg cells and CD8⁺Fxop3^-IL-10⁺Treg cells in peripheral blood among different groups. Conclusion: The percentages of CD8⁺Treg cells decrease in CRSwNP patients, especially in ECRS patients, which are opposite to that of Tc2 and Tc17, and negatively correlate with the eosinophils percentage. This indicates that the decrease in the ratio of CD8⁺Treg cell may be associated with the immune-imbalance and eosinophilic infiltration in nasal mucosa of CRS patients.

[Identification and expression profiling of R2R3-MYB transcription factors in Erigeron breviscapus]

R2 R3-MYB transcription factors are ubiquitous in plants, playing a role in the regulation of plant growth, development, and secondary metabolism. In this paper, the R2 R3-MYB transcription factors were identified by bioinformatics analysis of the genomic data of Erigeron breviscapus, and their gene sequences, structures, physical and chemical properties were analyzed. The functions of R2 R3-MYB transcription factors were predicted by cluster analysis. Meanwhile, the expression patterns of R2 R3-MYB transcription factors in response to hormone treatments were analyzed. A total of 108 R2 R3-MYB transcription factors, named EbMYB1-EbMYB108, were identified from the genome of E. breviscapus. Most of the R2 R3-MYB genes carried 2-4 exons. The phylogenetic tree of MYBs in E. breviscapus and Arabidopsis thaliala was constructed, which classified 234 MYBs into 30 subfamilies. The MYBs in the five MYB subfamilies of A.thaliala were clustered into independent clades, and those in E. breviscapus were clustered into four clades. The transcriptome data showed that MYB genes were differentially expressed in different tissues of E. breviscapus and in response to the treatments with exogenous hormones such as ABA, SA, and GA for different time. The transcription of 13 R2 R3-MYB genes did not change significantly, and the expression patterns of some genes were up-regulated or down-regulated with the extension of hormone treatment time. This study provides a theoretical basis for revealing the mechanisms of R2 R3-MYB transcription factors in regulating the growth and development, stress(hormone) response, and active ingredient accumulation in E. breviscapus.

[Effects of myocardial fibrosis on ischemic preconditioning against myocardial ischemia-reperfusion injury in type 2 diabetic rats]

Objective: To assess whether myocardial fibrosis affects the protective efficiency of ischemic preconditioning (IPC) against myocardial ischemia/reperfusion injury (MIRI) in type 2 diabetic rats. Methods: Type 2 diabetic rat model was established. Fifty-four normal and 54 diabetic spragus-dawley (SD) rats were equally divided into 6 groups (n=18) using the random number table method: (1) Control group (C group); (2) Ischemia reperfusion injury (IRI) control group (IRI group); (3) IPC group; (4) Diabetic control group (DC group); (5) Diabetic IRI group (DIRI group); (6) Diabetic IPC group (DIPC group). After the reperfusion, blood samples were obtained for measuring serum concentrations of creatine kinase-MB (CK-MB) and cardiac troponin I (cTnI) using enzyme-linked immunosorbent assay (ELISA). The myocardial infarction size (IS) was assessed by double staining method with Evan's blue and Triphenyl tetrazolium chloride (TTC), and the myocardial collagen volume fraction (CVF) and perivascular collagen area (PVCA) were assessed by Masson staining. Results: A stable and effective rat model with long-term diabetes was established in the current study. Compared with the normal rat groups, the CVF and PVCA significantly increased (all P<0.05) in the diabetic rat groups. The levels of CK-MB, cTnI and IS in the IPC group were (6.6±0.8) ng/ml, (0.5±0.1) ng/ml and (25.1±4.7) %, which showed significant decrease compared with (12.3±1.1) ng/ml, (1.2±0.3) ng/ml and (52.3±8.1) % in IRI group (all P<0.05). Among the diabetic rat groups, the CK-MB and cTnI levels in DIPC group were (11.5±0.9) and (1.1±0.1) ng/ml, apparently lower than the levels of (16.6±2.2) and (1.4±0.3) ng/ml in the DIRI group (both P<0.05). Compared with the IPC group, the IS, CK-MB and cTnI levels significantly increased in the DIPC group (all P<0.05). Conclusion: Myocardial fibrosis exists in rats with long-term type 2 diabetes, which weakens the protective effect of IPC on diabetes MIRI.

Expression levels of caspase-3 and gasdermin E and their involvement in the occurrence and prognosis of lung cancer

Background

Pyroptosis plays a dual role in the development of cancer and malignancy; as such, it may potentially be a new target for cancer treatment. However, the inflammatory response to pyroptosis may have adverse effects on the body. The roles of gasdermin E (GSDME), caspases, and related proteins associated with pyroptosis in cancer remain controversial.

Aim

The goal of this study was to determine whether the expression levels of caspase‐3 and GSDME affect the clinical stage, pathological grade, or survival prognosis of patients with lung cancer.

Methods

We examined the protein levels of GSDME, caspase‐3, caspase‐8, and caspase‐9 in lung tissue samples from 100 patients with lung cancer by using immunohistochemistry.

Results

We found that GSDME, caspase‐3, and caspase‐8 were more highly expressed in tumor tissues than in adjacent normal tissues. Moreover, we found that GSDME could serve as a prognostic factor as there was a positive correlation between its expression level and the postoperative survival rate of patients with lung cancer.

Conclusions

GSDME may be an independent factor affecting the prognosis of patients with lung cancer. However, the role of GSDME and its related proteins in cancer requires further research.

[miR-18a enhances the radiosensitivity of nasopharyngeal carcinoma cells through inducing autophagy]

Objective: To explore the impacts of miR-18a overexpression or depression on the radiosensitivities of nasopharyngeal carcinoma cell line CNE1 and CNE2 and underlying mechanisms. Methods: CNE1 and CNE2 were transfected with miR-18a mimics, inhibitor and the corresponding control vectors. qRT-PCR and western blot were used to determine the ataxia telangiectasia mutated (ATM) expressions in CNE1 and CNE2. CNE1 and CNE2 with stably expressing miR-18a and miR-18a siRNA were constructed. Methyl thiazolyl tetrazolium (MTT) assay was used to detect the impacts of the miR-18a overexpression or depression combined with irradiation on the cell growth. Flow cytometry was used to detect the cell apoptosis and cell cycle. Colony formation assay was used to evaluate the raodiosensitivities of cells. Acridine orange (AO) staining and western blot were used respectively to test the autophagy and the expressions of related proteins. Independent samples t test was used to compare the mean value between groups by using SPSS 16.0. Results: ATM mRNA was decreased significantly in CNE1 and CNE2 cells transfected with 100 or 200 nmol/L miR-18a mimics for 48 hours (CNE1: RQ=0.174±0.139 and 0.003±0.001, t=9.939 and 19 470.783;CNE2: RQ=0.024±0.008 and 0.019±0.012, t=270.230 and 137.746, respectively, all P<0.001). ATM proteins were also decreased after transfected with 100 or 200 nmol/L miR-18a mimics for 72 hours. While in the cells transfected with 100 and 200 nmol/L miR-18a inhibitor for 48 hours, the expressions of ATM mRNA were upregulated significantly (CNE1: RQ=9.419±2.495 and 2.500±1.063, t=-4.427 and -41.241; CNE2: RQ=7.210±0.171 and 115.875±15.805, t=-62.789 and -12.589, all P<0.05), and the expressions of ATM proteins increased after transfected for 72 hours. The growth of cells with miR-18a overexpression plus 4 Gy irradiation were obviously inhibited compared to that of cells with the 4Gy irradiation alone; while the growth of miR-18a-inhibited cells increased compared to that of cells with 4 Gy irradiation alone (all P<0.05). CNE1 transfected with 100 nmol/L miR-18a mimics plus 4 Gy irradiation showed the higher apoptosis rate than the cells with 4 Gy irradiation alone ((22.9±2.1)% vs. (16.3±1.0)%, t=-4.870, P<0.01). Compared to the cells with 4 Gy irradiation alone, miR-18a-overexpressed cells plus 4 Gy irradiation decreased their percentages in G1 phases ((20.2±3.0)% vs. (29.8±4.4)%, t=3.119) and G2/M phases ((21.5±0.9)% vs. (33.4±3.1)%, t=6.410, P<0.05 for both), and increased their percentages in S phases ((56.7±4.9)% vs. (36.8±6.4)%, t=-4.246, P<0.05), and these cells possessed less colony number after exposure to different doses of irradiation, more autophagy-lysosome number, and more expressions of LC3 proteins (all P<0.05). There were no significant differences in the expressions of p62 expressions between different groups of cells. Conclusion: Overexpression of miR-18a can enhance the radiosensitivities of NPC cells by targeting ATM to abrogate G1/S, G2/M arrest and to induce autophagy and apoptosis.

Gene-Environment Interactions Between Environmental Response Genes Polymorphisms and Mitochondrial DNA Copy Numbers Among Benzene Workers

OBJECTIVE

To determine the effect of mitochondrial DNA copy number (mtDNAcn) as a biomarker of benzene exposure.

METHODS

A total of 294 benzene-exposed workers and 102 controls were recruited. Biomarkers of mtDNAcn, cytokinesis-block micronucleus (MN) frequency, and peripheral blood white blood cells (WBC) were detected. Eighteen polymorphism sites in DNA damage repair and metabolic genes were analyzed.

RESULTS

Benzene exposure increased mtDNAcn and indicated a dose-response relationship (P < 0.001). mtDNAcn was negatively correlated with WBC count and DNA methylation and positively correlated with MN frequency. The AG type in rs1695 interacted with benzene exposure to aggravate mtDNAcn (β = 0.006, 95% CI: 0, 0.012, P = 0.050). rs13181, rs1695, rs1800975, and GSTM1 null were associated with benzene-induced mtDNAcn. Rs1695 interacted with benzene to increase mitochondrial damage.

CONCLUSIONS

Benzene exposure increases mtDNAcn levels in benzene-exposed workers.

Identification of two UDP-glycosyltransferases involved in the main oleanane-type ginsenosides in Panax japonicus var. major

Two UDP-glycosyltransferases from Panax japonicus var. major were identified, and the biosynthetic pathways of three oleanane-type ginsenosides (chikusetsusaponin IVa, ginsenoside Ro, zingibroside R₁) were elucidated. Chikusetsusaponin IVa and ginsenoside Ro are primary active components formed by stepwise glycosylation of oleanolic acid in five medicinal plants of the genus Panax. However, the key UDP-glycosyltransferases (UGTs) in the biosynthetic pathway of chikusetsusaponin IVa and ginsenoside Ro are still unclear. In this study, two UGTs (PjmUGT1 and PjmUGT2) from Panax japonicus var. major involved in the biosynthesis of chikusetsusaponin IVa and ginsenoside Ro were identified based on bioinformatics analysis, heterologous expression and enzyme assays. The results show that PjmUGT1 can transfer a glucose moiety to the C-28 carboxyl groups of oleanolic acid 3-O-β-D-glucuronide and zingibroside R₁ to form chikusetsusaponin IVa and ginsenoside Ro, respectively. Meanwhile, PjmUGT2 can transfer a glucose moiety to oleanolic acid 3-O-β-D-glucuronide and chikusetsusaponin IVa to form zingibroside R₁ and ginsenoside Ro. This work uncovered the biosynthetic mechanism of chikusetsusaponin IVa and ginsenoside Ro, providing the rational production of valuable saponins through synthetic biology strategy.

[The expression of Notch pathway in nasal polyps and its correlation with the decreased Treg percentage and eosinophil infiltration]

Objective: To investigate the correlation between Notch pathway expression in nasal polyps and Treg percentage and Eos infiltration. Methods: Patients with chronic sinusitis and simple nasal septum deviation who received nasal endoscopic surgery in the Third Affiliated Hospital of Sun Yat-Sen University between November 2012 and August 2018 were selected and enrolled in CRS group and control group respectively. Nasal mucosa tissues were collected from 30 CRSsNP patients (14 males and 16 females aged from 18 to 63), 58 CRSwNP patients (38 males and 20 females aged from 18 to 65) and 29 patients (19 males and 10 females aged from 20 to 57), who underwent nasal endoscopic surgery for correction of simple nasal septum deviation. Hematoxylin-eosin(HE) staining was used to observe the infiltration of eosinophilic granulocytes in the tissues and to classify chronic sinusitis with polyps (CRSwNP) into eosinophilic chronic rhinosinusitis with nasal polyps (Eos-CRSwNP)and non-eosinophilic chronic rhinosinusitis with nasal polyps (Eos-CRSwNP). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of Notch pathway receptors (Notch-l, 2, 3, 4) and their ligands (Jagded-l, Jagded-2, Delta-l, Delta-3and Delta-4) in the nasal mucosa of each group, as well as the expression of Th2 cytokines (IL-4, IL-5, IL-13), eosinophilic cationic protein (ECP)and the key transcription factor Foxp3 in Treg cells. Finally, flow cytometry was used to detect CD4+CD25+Foxp3+ Treg cells in nasal mucosa of each group. Results: Compared with controls, the expression of Th2 cytokines (IL-4, IL-5, IL-13) in CRSsNP and non-Eos-CRSwNP patients was the highest in Eos-CRSwNP (F=16.930,9.197,9.116, all P<0.05). Foxp3 had the lowest expression in Eos-CRSwNP patients and was lower than non-Eos-CRSwNP patients (F=2.780,P<0.05), and was negatively correlated with ECP (r=-0.326,P<0.05). Compared with controls, Eos-CRSwNP patients in CRSsNP patients and non-Eos-CRSwNP patients exhibited a significantly lower frequency of CD4+CD25+Foxp3+Treg cells (F=13.140, all P<0.01). The expression of Notch-l and Jagged-l in Eos-CRSwNP was significantly higher than that of the controls, CRSsNP patients and non-Eos-CRSwNP patients (F=5.953/F=6.380, P<0.05). In the nasal polyp group, the expression of Notch-l and Jagged-l showed significantly negative correlation with Foxp3 (r=-0.611/-0.346, all P<0.05), and positive correlation with Th2 cytokines (IL-4, IL-5, IL-13) and ECP, respectively (r=0.781/0.459,0.621/0.601,0.605/0.490,0.464/0.668, all P<0.05). There was no significant difference in the expression of receptor and ligand of the other Notch pathway among the groups. Conclusion: Abnormal activation of Notch-l/Jagged-l pathway may be involved in decreasing Treg ratio in Eos-CRSwNP, thereby promoting Th2 inflammatory response and Eosinophil infiltration.

Sex Dimorphic Associations of Gestational Diabetes Mellitus With Cord Plasma Fatty Acid Binding Protein 4 and Estradiol

Fatty acid binding protein 4 (FABP4) has been associated with insulin resistance. Gestational diabetes mellitus (GDM) impairs fetal insulin sensitivity. Female newborns are more insulin resistant than male newborns. We sought to evaluate the association between GDM and cord blood FABP4, and explore potential sex dimorphic associations and the roles of sex hormones. This was a nested case-control study in the Shanghai Birth Cohort, including 153 pairs of newborns in GDM vs. euglycemic pregnancies matched by infant sex and gestational age at delivery. Cord plasma FABP4, leptin, total and high-molecular-weight adiponectin, testosterone and estradiol concentrations were measured. Adjusting for maternal and neonatal characteristics, cord plasma FABP4 (Mean ± SD: 27.0 ± 19.6 vs. 18.8 ± 9.6 ng/mL, P=0.045) and estradiol (52.0 ± 28.6 vs. 44.2 ± 26.6, ng/mL, P=0.005) concentrations were higher comparing GDM vs. euglycemic pregnancies in males, but similar in females (all P>0.5). Mediation analyses showed that the positive association between GDM and cord plasma FABP4 in males could be partly mediated by estradiol (P=0.03), but not by testosterone (P=0.72). Cord plasma FABP4 was positively correlated with total adiponectin in females (r=0.17, P=0.053), but the correlation was in the opposite direction in males (r=-0.11, P=0.16) (test for difference in r, P=0.02). Cord plasma FABP4 was not correlated with leptin in both sexes. The study is the first to demonstrate sex-dimorphic associations between GDM and cord plasma FABP4 or estradiol, and between FABP4 and adiponectin in newborns. GDM may affect fetal circulating FABP4 and estradiol levels in males only.

Fibroblast Growth Factor 19 in Gestational Diabetes Mellitus and Fetal Growth

Fibroblast growth factor 19 (FGF19) has been implicated in glucose homeostasis. Gestational diabetes mellitus (GDM) enhances fetal insulin secretion and fetal growth. Girls weigh less and are more insulin resistant than boys at birth. We sought to assess whether FGF19 is associated with GDM and fetal growth and explore potential sex dimorphic associations. This was a nested case-control study in the Shanghai Birth Cohort, including 153 pairs of newborns of GDM versus euglycemic mothers matched by infant's sex and gestational age at birth. Cord plasma FGF19, insulin, C-peptide, proinsulin, IGF-I and IGF-II concentrations were measured. Cord plasma FGF19 concentrations were similar in GDM versus euglycemic pregnancies (mean ± SD: 43.5 ± 28.2 versus 44.5 ± 30.2 pg/mL, P=0.38). FGF19 was not correlated with IGF-I or IGF-II. FGF19 concentrations were positively correlated with birth weight (r=0.23, P=0.01) and length (r=0.21, P=0.02) z scores, C-peptide (r=0.27, P=0.002) and proinsulin (r=0.27, P=0.002) concentrations in females. Each SD increment in cord plasma FGF19 was associated with a 0.25 (0.07-0.43) increase in birth weight z score in females. In contrast, FGF19 was not correlated with birth weight or length in males. These sex dimorphic associations remained after adjusting for maternal and neonatal characteristics. The study is the first to demonstrate that GDM does not matter for cord blood FGF19 concentrations. The female specific positive correlation between FGF19 and birth weight is suggestive of a sex-dimorphic role of FGF19 in fetal growth. The observations call for more studies to validate the novel findings and elucidate the underlying mechanisms.

Construction of a recombinant vaccinia virus expressing Babesia gibsoni thrombospondin-related anonymous protein and evaluation of its immunogenicity in mice

Previously, we have identified a gene encoding thrombospondin-related anonymous protein of Babesia gibsoni (BgTRAP), and have shown that the antisera raised against recombinant BgTRAP expressed in Escherichia coli inhibited the growth of parasites. In the present study, a recombinant vaccinia virus expressing the BgTRAP (VV/BgTRAP) was constructed. A specific band with a molecular mass of 80 kDa, which is similar to that of native BgTRAP on the merozoites of B. gibsoni, was detected in the supernatant of VV/ BgTRAP-infected RK13 cells. Mice inoculated with VV/BgTRAP produced a specific antiBgTRAP response. The antiserum against VV/BgTRAP showed reactivity against the native BgTRAP on parasites. These results indicated that the recombinant vaccinia virus expressing BgTRAP might be a vaccine candidate against canine B. gibsoni infection.

[Evaluation of clinical application of transjugular liver biopsy in 61 cases]

Objective: To evaluate the effectiveness and safety of transjugular liver biopsy (TJLB) in clinical applications. Methods: Clinical data of patients who underwent TJLB in the Beijing Friendship Hospital Affiliated to Capital Medical University from November 2017 to March 2019 were retrospectively reviewed. Clinical characteristics, indications and biopsy complications and the samples quality were analyzed. Results: Among 61 cases who underwent TJLB, 32 were males and 29 were females, aged 16 to 79 years. There were 43 cases (70.5%) with abnormal coagulation function, among which the prothrombin time activity percentage (39%) and platelet count (24×10(9)/L ) were lowest. 38 cases (62.3%) had perihepatic fluid. One case was obese, and had a body mass index of 31kg/m2. 56 cases (91.8%) were successfully biopsied. 51 cases (83.6%) liver tissue samples were assessed with pathological diagnosis. Five cases (8.2%) had serious complications. 14 cases (23.0%) had mild complications, and no patients died. Conclusion: TJLB is a safe and feasible method for patients who have contraindications to percutaneous liver biopsy.

[Expression and cellular provenance of interleukin 17A in non-eosinophilic chronic rhinosinusitis with nasal polyps]

Objective: To investigate the expression and cellular provenance of interleukin 17A (IL-17A) in non-eosinophilic chronic rhinosinusitis with nasal polyps (nECRSwNP), and to analyze the possible reasons for its different expression. Methods: Samples were collected from 14 patients with eosinophilic chronic rhinosinusitis with nasal polyps (ECRSwNP) and 28 patients with nECRSwNP, who underwent functional endoscopic sinus surgery in the Third Affiliated Hospital of Sun Yat-sen University from January 2017 to May 2018, including 33 males and 9 females, with the age ranging from 18 to 65 years old. Enzyme linked immune sorbent assay (ELISA) and flow cytometry were used to investigate the expression and cellular origins of IL-17A in the nasal tissue of ECRSwNP and nECRSwNP groups. Then the difference of quantity and differentiation ability of the major cells producing IL-17A between ECRSwNP and nECRSwNP groups were analyzed by flow cytometry. Finally, the expressions of IL-6, transforming growth factor-β(TGF-β), and IL-23, which were considered as the important factors in promoting Th17/Tc17 differentiation in CRSwNP and their correlation with IL-17A, were analyzed by ELISA. Statistical analysis was performed using IBM SPSS 20. Results: The IL-17A protein levels and IL-17A(+)lymphocyte percentages were higher in nECRSwNP group compared with that of the ECRSwNP group (158.56 (167.76) pg/ml (M(QR)) vs. 9.42 (11.33) pg/ml, 10.21%±1.54% (x±s) vs. 3.93%±0.80%, Z=2.95, t=3.62, all P<0.01). Tc17 cells (CD8(+)T cells producing IL-17A) and Th17 cells (CD4(+)T cells producing IL-17A) were major IL-17A producers in both ECRSwNP and nECRSwNP group. Further analysis revealed that there was no significant difference in quantity of CD8(+)and CD4(+)T cells between ECRSwNP and nECRSwNP group, but the differentiation ability about CD8(+)and CD4(+)T cells differentiating into Tc17 and Th17 in nECRSwNP group was stronger than that in ECRSwNP. The high expressions of IL-6 and TGF-β, which were considered as the important factors in promoting Th17/Tc17 differentiation were also found in nECRSwNP group compared with ECRSwNP (56.07 (234.25) pg/ml vs. 8.27 (12.51) pg/ml, (5.44±0.34) pg/ml vs. (4.17±0.22) pg/ml, Z=2.426, t=2.29, all P<0.05). But the difference in expression of IL-23 was not significant difference between the two groups. Moreover, the expression of IL-17A showed significantly positive correlation with IL-6 (r=0.615, P=0.009). No positive correlation between IL-17A and TGF-β or IL-23 was observed. Conclusions: The expression of IL-17A in nasal mucosa of nECRSwNP patients is significantly higher than that of ECRSwNP, which is due to the increase of expression and differentiation of Tc17/Th17 cells. IL-17A shows positive correlation with IL-6 in CRSwNP, which is the important factor in promoting Th17/Tc17 differentiation.

Promoter hypermethylation in CSF3R induces peripheral neutrophil reduction in benzene-exposure poisoning

Benzene is a global pollutant and has been established to cause leukemia. To better understand the role of DNA methylation in benzene toxicity, peripheral blood mononuclear cells were collected from six benzene-poisoning patients and six matched controls for genome-wide DNA methylation screening by Illumina Infinium Methylation 450 BeadChip. The Gene Chip Human Gene 2.0 ST Array (Affymetrix) was used to analyze global mRNA expression. Compared with the corresponding sites of controls, 442 sites in patients were hypermethylated, corresponding to 253 genes, and 237 sites were hypomethylated, corresponding to 130 genes. The promoter methylation and mRNA expression of CSF3R, CREB5, and F2R were selected for verification by bisulfite sequencing and real-time PCR in a larger data set with 21 cases and 23 controls. The results indicated that promoter methylation of CSF3R (p = .005) and F2R (p = .015) was significantly higher in cases than in controls. Correlation analysis showed that the promoter methylation of CSF3R (p < .001) and F2R (p < .001) was highly correlated with its mRNA expression. In the poisoning cases, neutrophil percentage was significantly different among the high, middle, and low CSF3R-methylation groups (p = .002). In particular, the neutrophil percentage in the high CSF3R-methylation group (48.10 ± 9.63%) was significantly lower than that in the low CSF3R-methylation group (59.30 ± 6.26%) (p = .012). The correlation coefficient between promoter methylation in CSF3R and the neutrophil percentage was -0.445 (p = .020) in cases and - 0.398 (p = .060) in controls. These results imply that hypermethylation occurs in the CSF3R promoter due to benzene exposure and is significantly associated with a reduction in neutrophils.

Maternal prenatal urinary bisphenol A level and child cardio-metabolic risk factors: A prospective cohort study

Exposure to endocrine disrupting chemicals during the first 1000 days of life may have long-lasting adverse effects on cardio-metabolic risk in later life. This study aimed to examine the associations between maternal prenatal Bisphenol A (BPA) exposure and child cardio-metabolic risk factors at age 2 years in a prospective cohort. During 2012-2013, 218 pregnant women were enrolled at late pregnancy from Shanghai, China. Urinary BPA concentration was measured in prenatal and child 2-year spot urine samples, and classified into high, medium and low tertiles. Child adiposity anthropometric measurements, random morning plasma glucose, serum insulin, and lipids (high-density lipoprotein, low-density lipoprotein, cholesterol, triglyceride), systolic (SBP) and diastolic blood pressure (DBP) were measured. Linear regression was used to evaluate the associations between prenatal BPA and each of the cardio-metabolic risk factors in boys and girls, respectively, adjusting for pertinent prenatal, perinatal and postnatal factors. BPA was detectable (>0.1 μg/L) in 98.2% of mothers prenatally and 99.4% of children at age 2 years. Compared to those with low prenatal BPA, mean SBP was 7.0 (95%CI: 2.9-11.2) mmHg higher, and DBP was 4.4 (95%CI: 1.2-7.5) mmHg higher in girls with high prenatal BPA levels, but these associations were not found in boys. In boys, medium maternal prenatal BPA level was associated with 0.36 (95% CI: 0.04-0.68) mmol/L higher plasma glucose. No associations were found between prenatal BPA and child BMI, skinfold thicknesses, serum lipids, or insulin in either girls or boys. There were no associations between concurrent child urinary BPA and cardio-metabolic risk factors. These results support that BPA exposure during prenatal period, susceptible time for fetal development, may be associated with increase in child BP and plasma glucose in a sex-specific manner. Further independent cohort studies are needed to confirm the findings.

Interaction effects of environmental response gene polymorphisms and benzene exposure on telomere length in shoe-making workers

Benzene is a globally occurring environmental and occupational pollutant that causes leukemia. To better understand telomere length (TL) as a function of benzene toxicity, we recruited 294 shoe-making workers and 102 controls from Wenzhou, China in 2011. Biomarkers of TL, cytokinesis-block micronucleus (MN) frequency, and white blood cells (WBC) were measured. In total, 18 polymorphic sites in environmental response genes, including metabolic and DNA repair genes, were analyzed. Results indicate that benzene exposure led to a longer TL at a threshold of 32 mg/m³-year of cumulative exposure dose (CED). Furthermore, the TL was longer in members of the damaged group, when evaluated for MN frequency (P < 0.001) and reduced WBC (P < 0.001), than in those of the normal group. Workers carrying genotype TT (β = 0.32, P = 0.042) in rs3212986 of ERCC1 and genotype TC (β = 0.24, P = 0.082) in rs1051740 of mEH exon3 were associated with a longer TL as compared to the wild-type group. TA (β = -0.53, P < 0.001) in rs6413432 of CYP2E1 was associated with a shorter TL. Benzene exposure interacted with the TA type in rs6413432 (β = 0.003, 95% CI: 0, 0.006, P = 0.042) and the CC type in rs1051740 (β = 0.007, 95% CI: 0.001, 0.013, P = 0.015) after adjusting for confounding factors. Our results indicate that benzene induces an increase in TL at a threshold of CED ≥32mg/m³-year. Rs1051740, rs3212986, and rs6413432 were found to be involved in benzene-induced telomere growth; in particular, rs1051740 and rs6413432 interacted with the benzene exposure, resulting in an extended TL.

Sex dimorphism in the associations of gestational diabetes with cord blood adiponectin and retinol-binding protein 4

INTRODUCTION

Gestational diabetes (GD) is associated with impaired insulin sensitivity in newborns. Adiponectin and retinol-binding protein 4 (RBP-4) are involved in regulating insulin sensitivity. Females are more likely to develop diabetes at young ages than males. We tested the hypothesis that GD may affect RBP-4 and adiponectin levels in early life, and there may be sex-dimorphic associations.

RESEARCH DESIGN AND METHODS

In a nested case-control study of 153 matched pairs of neonates of mothers with GD and euglycemic pregnancies in the Shanghai Birth Cohort, we evaluated cord plasma leptin, high molecular weight (HMW) and total adiponectin and RBP-4 concentrations.

RESULTS

Comparing GD versus euglycemic pregnancies adjusted for maternal and neonatal characteristics in female newborns, cord plasma total adiponectin (mean±SD: 30.8±14.3 vs 37.1±16.1 µg/mL, p=0.048) and HMW adiponectin (14.6±7.7 vs 19.3±8.3 µg/mL, p=0.004) concentrations were lower, while RBP-4 concentrations were higher (21.7±5.4 vs 20.0±4.8 µg/mL, p=0.007). In contrast, there were no differences in male newborns (all p>0.2). RBP-4 concentrations were higher in female versus male newborns (21.7±5.4 vs 18.8±4.5 µg/mL, p<0.001) in GD pregnancies only. HMW adiponectin concentrations were significantly higher in female versus male newborns in euglycemic pregnancies only (19.3±8.3 vs 16.1±7.4 µg/mL, p=0.014).

CONCLUSIONS

GD was associated with lower cord plasma HMW adiponectin and higher RBP-4 concentrations in female newborns only. The study is the first to reveal a sex-dimorphic early life impact of GD on metabolic health biomarkers in the offspring. GD may alter the normal presence (HMW adiponectin) or absence (RBP-4) of sex dimorphism in some insulin sensitivity regulation-relevant adipokines in early life.

Dataset on the effect of Benzene exposure on genetic damage, hematotoxicity, telomere length and polymorphisms in metabolic and DNA repair genes

In this paper, we present an occupational dataset to evaluate benzene exposure on the effective biomarkers of genetic damage, indicated as cytokinesis-block micronucleus (MN) frequency, hematotoxicity, indicated as white blood cells (WBC) counts, and molecular marker of telomere length (TL). And we further to eliminate the mechanism of benzene induced damage. Then evaluate the effects of sites polymorphism in environmental response genes, including 18 sites in metabolic and DNA repair genes, and the interaction between gene polymorphism and benzene exposure. This dataset is supplementary to the submitted research by [1] focused on the biomarkers TL, and a detailed description of the subjects sampling, biomarkers detection, data analysis and discussion are discussed in detail.

Defect Dynamic Model of the Synergistic Effect in Neutron- and γ-Ray-Irradiated Silicon NPN Transistors

A defect dynamic model is proposed for the positive synergistic effect of neutron- and γ-ray-irradiated silicon NPN transistors. The model considers a γ-ray-induced transformation and annihilation of the neutron-induced divacancy defects in the p-type base region of the transistor. The derived model of the base current predicts a growth function of the γ-ray dose that approaches exponentially an asymptotic value, which depends linearly on the neutron-induced initial displacement damage (DD) and a linear decay function of the dose whose slope depends quadratically on the initial DD. Variable fluence and dose neutron-γ-ray irradiation experiments are carried out, and we find all of the novel dose and fluence dependence predicted by the proposed model are confirmed by the measured data. Our work, hence, identifies that the defect evolution under γ-ray irradiation, rather than the widely believed interface Coulomb interaction, is the dominating mechanism of the synergistic effect. Our work also paves the way for the modification of displacement defects in silicon by γ-ray irradiation.

Rational Interface Engineering for Efficient Flexible Perovskite Light-Emitting Diodes

Although perovskite light-emitting diodes (PeLEDs) are promising for next-generation displays and lighting, their efficiency is still considerably below that of conventional inorganic and organic counterparts. Significant efforts in various aspects of the electroluminescence process are required to achieve high-performance PeLEDs. Here, we present an improved flexible PeLED structure based on the rational interface engineering for energy-efficient photon generation and enhanced light outcoupling. The interface-stimulated crystallization and defect passivation of the perovskite emitter are synergistically realized by tuning the underlying interlayer, leading to the suppression of trap-mediated nonradiative recombination losses. Besides approaching highly emissive perovskite layers, the outcoupling of trapped light is also enhanced by combining the silver nanowires-based electrode with quasi-random nanopatterns on flexible plastic substrate. Upon the collective optimization of the device structure, a record external quantum efficiency of 24.5% is achieved for flexible PeLEDs based on green-emitting CsPbBr₃ perovskite.

Management of Delayed Fluorophor-Sensitized Exciton Harvesting for Stable and Efficient All-Fluorescent White Organic Light-Emitting Diodes

White organic light-emitting diodes (WOLEDs) using thermally activated delayed fluorescence (TADF)-based single emissive layer (SEL) have attracted enormous attention because of their simple device structure and full exciton utilization potential for high efficiency. However, WOLEDs made of an all-TADF SEL usually exhibit serious efficiency roll-off and poor color stability due to serious exciton-annihilation and unbalanced radiative decays of different TADF emitters. Herein, a new strategy is proposed to manipulate the TADF-sensitized fluorescence process by combining dual-host systems of high triplet energy with a conventional fluorescent emitter of complementary color. The multiple energy-funneling paths are modulated and short-range Dexter energy transfer is largely suppressed due to the steric effect of peripheral tert-butyl group in the blue TADF sensitizer. The resulting all-fluorescent WOLEDs achieve an unprecedentedly high external quantum efficiency of 21.8% with balanced white emission of Commission Internationale de l'Eclairage coordinate of (0.292, 0.343), accompanied with good color stability, reduced efficiency roll-off, and prolonged operational lifetime. These findings demonstrate the validity of this strategy for precisely allocating the exciton harvesting in SEL WOLEDs.

Low-level lead exposure is associated with aberrant sperm quality and reproductive hormone levels in Chinese male individuals: Results from the MARHCS study low-level lead exposure is associated with aberrant sperm quality

Studies in animals suggest an adverse effect of high-level lead exposure on male reproductive outcomes. However, evidence of the effects of low-level lead exposure is inconsistent. The purpose of our study was to explore the relationship between low-level lead exposure from daily environmental contaminants and semen quality in a community population without occupational exposure. We recruited 751 students in the Male Reproductive Health in Chongqing College Students (MARHCS) study and 190 community males from Bishan, Chongqing. Eight urinary metals (Pb, Cd, As, Cu, Zn, Ni, Mn, and Cr), semen quality, and serum sex hormones were detected. Even if the blood lead concentration was below the US lead poisoning standard for children (100 μg/L), a significant dose-response relationship was found between lead exposure and a decrease in semen quality. Multilinear regression showed that urinary Pb was negatively associated with sperm concentration, total sperm count, progressive motility and total sperm motility (regression coefficient: -0.074, -0.103, -0.024, and -0.014, respectively; p: <0.001, <0.001, 0.007, and <0.001, respectively), accompanied by decreased serum follicle-stimulating hormone, serum testosterone and the testosterone/luteinizing hormone ratio (β coefficient: -0.090, -0.082, and -0.020, respectively; p: 0.002, <0.001, and 0.021, respectively). Logistic regression also indicated that the risk of having abnormal semen quality was higher in the high Pb group (OR: 2.501, 95% CI: 1.411, 4.435, p = 0.002) than in the low Pb group after adjusting for confounders, with a dose-response relationship in the trend test (p = 0.007). Our results revealed an inverse association between Pb exposure at low levels and semen quality.

Fetuin-A and fetal growth in gestational diabetes mellitus

OBJECTIVE

Fetuin-A is a glycoprotein produced by hepatocytes and has been associated with insulin resistance and bone growth in postnatal life. Gestational diabetes mellitus (GDM) is a condition characterized by insulin resistance. It is unclear whether GDM may affect cord blood fetuin-A levels and whether fetuin-A is associated with fetal growth.

RESEARCH DESIGN AND METHODS

In a nested case-control study of 153 matched pairs of neonates of mothers with GDM and euglycemic pregnancies in the Shanghai Birth Cohort, we evaluated cord blood fetuin-A in association with GDM and fetal growth.

RESULTS

Comparing the newborns of GDM versus euglycemic mothers, cord blood fetuin-A concentrations were similar (mean±SD: 783.6±320.0 vs 754.8±281.9 µg/mL, p=0.53), while insulin-like growth factor (IGF)-I (76.6±27.8 ng/mL vs 68.1±25.1 ng/mL, p=0.008) and IGF-II (195.3±32.5 ng/mL vs 187.5±30.8 ng/mL, p=0.042) concentrations were higher. Cord blood fetuin-A was not correlated with insulin, IGF-I or IGF-II. Cord blood fetuin-A was negatively correlated with birth weight (r=-0.19, p=0.025) and birth length (r=-0.24, p=0.005) z scores in GDM pregnancies, while there were no significant correlations in euglycemic pregnancies (tests for interaction: p=0.014 for birth length, p=0.013 for birth length). Adjusting for maternal and neonatal characteristics, the differential associations remained.

CONCLUSIONS

GDM was not associated with cord blood fetuin-A levels. Fetuin-A was negatively associated with fetal growth in GDM but not in euglycemic pregnancies. This novel observation suggests a GDM-conditional negative correlation of fetuin-A with fetal growth.

Fetuin-A in Infants Born Small- or Large-for-Gestational-Age

Fetuin-A is a multifunctional glycoprotein that has been implicated in insulin resistance and bone metabolism. We assessed whether fetuin-A is associated with poor or excessive fetal growth. In the Shanghai Birth Cohort, we conducted a nested case-control study of 60 trios of small-for-gestational-age (SGA, birth weight <10th percentile), optimal-for-gestational-age (OGA, 25-75th, the reference) and large-for-gestational-age (LGA, >90th percentile) infants matched by sex and gestational age. Cord plasma concentrations of fetuin-A and fetal growth factors [insulin, proinsulin, insulin-like growth factor (IGF)-I and IGF-II] were measured. Cord plasma fetuin-A concentrations were higher in SGA (809.4 ± 306.9 μg/ml, P = 0.026) and LGA (924.2 ± 375.9 μg/ml, P < 0.001) relative to OGA (680.7 ± 262.1 μg/ml) newborns, and were not correlated to insulin, proinsulin, IGF-I and IGF-II (all P > 0.2). Higher fetuin-A concentrations were associated with increased risks of SGA [OR = 1.67 (1.08-2.58) per SD increment, P = 0.024] and LGA [OR = 2.36 (1.53-3.66), P < 0.001]. Adjusting for maternal and neonatal characteristics and fetal growth factors, the elevated risk changed little for LGA [adjusted OR = 2.28 (1.29-4.01), P = 0.005], but became non-significant for SGA (P = 0.202). Our study is the first to demonstrate that fetuin-A may be involved in excessive fetal growth. This association is independent of fetal growth factors.

Statistical Analysis of the Heart and Lung Mass in Forensic Anatomical Cases and Its Forensic Significance

Abstract

Objective To investigate the differences of heart mass and lung mass in forensic autopsy cases and to explore their application value in forensic identification. Methods The data from 1 614 autopsy cases accepted by center of Medico-legal Investigation of China Medical University between 2007 to 2016 were collected. The correlation of heart and lung mass with age, height, body weight, and body mass index （BMI）, as well as differences in different causes of death were analyzed by GraphPad Prism 6.0 software. Results The heart mass and lung mass of males were higher than those of females （P<0.05）. The heart mass of males and females was positively correlated with age, height, body weight and body mass index （BMI） （P<0.05）. The heart mass of patients dying from sudden cardiac death （SCD） was significantly higher than those dying from other causes of death. The lung mass of patients dying from drowning and delayed treatment was higher than those dying from other causes of death （P<0.05）. Conclusion In forensic practice, measurement of the heart mass and lung mass has certain significance for differential diagnosis and diagnosis of different causes of death.

Illumina-based transcriptomic analysis on recalcitrant seeds of Panax notoginseng for the dormancy release during the after-ripening process

Panax notoginseng (Burk) F.H. Chen is an economically and medicinally important plant of the family Araliacease, with seed dormancy being a key factor limiting the extended cultivation of P. notoginseng. The seeds belong to the morphophysiological dormancy (MPD) group, and it has also been described as the recalcitrant seed. To date, the molecular mechanism of dormancy release in the recalcitrant seed of P. notoginseng is unknown. In the present study, the transcript profiles of seeds from different after-ripening stages (0, 20, 40 and 60 days) were investigated using Illumina Hiseq 2500 technology. 91 979 946 clean reads were generated, and 81 575 unigenes were annotated in at least one database. In addition, the differentially expressed genes (DEGs) were identified by the pairwise comparisons. We screened out 2483 DEGs by the three key groups of 20 days vs 0 d, 40 d vs 0 d and 60 d vs 0 d. The DEGs were analyzed by gene ontology enrichment and Kyoto Encyclopedia of Genes and Genomes pathway annotation. Meanwhile, we obtained 78 DEGs related to seeds dormancy release at different after-ripening stages of P. notoginseng, of which 15 DEGs were associated with abscisic acid and gibberellin. 26 DEGs that encode late embryogenesis abundant protein and antioxidant enzyme were correlated with desiccation tolerance in seeds. In summary, the results obtained here showed that PECTINESTERASE-2-LIKE, GA-INSENSITIVE, ENT-KAURENE SYNTHASE, PROTEIN PHOSPHATASE 2C, GIBBERELLIN 2-BETA-DIOXYGENASE, SUPEROXIDE DISMUTASE, L-ASCORBATE PEROXIDASE, CATALASE, LATE EMBRYOGENESIS ABUNDANT PROTEIN DC3 and DEHYDRIN 9 were potentially involved in dormancy release and desiccation sensitivity of P. notoginseng seeds. The data might provide a basis for researches on MPD.

Comparative transcriptome and metabolome analyses provide new insights into the molecular mechanisms underlying taproot thickening in Panax notoginseng

BACKGROUND

Taproot thickening is a complex biological process that is dependent on the coordinated expression of genes controlled by both environmental and developmental factors. Panax notoginseng is an important Chinese medicinal herb that is characterized by an enlarged taproot as the main organ of saponin accumulation. However, the molecular mechanisms of taproot enlargement are poorly understood.

RESULTS

A total of 29,957 differentially expressed genes (DEGs) were identified during the thickening process in the taproots of P. notoginseng. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment revealed that DEGs associated with "plant hormone signal transduction," "starch and sucrose metabolism," and "phenylpropanoid biosynthesis" were predominantly enriched. Further analysis identified some critical genes (e.g., RNase-like major storage protein, DA1-related protein, and Starch branching enzyme I) and metabolites (e.g., sucrose, glucose, fructose, malate, and arginine) that potentially control taproot thickening. Several aspects including hormone crosstalk, transcriptional regulation, homeostatic regulation between sugar and starch, and cell wall metabolism, were identified as important for the thickening process in the taproot of P. notoginseng.

CONCLUSION

The results provide a molecular regulatory network of taproot thickening in P. notoginseng and facilitate the further characterization of the genes responsible for taproot formation in root medicinal plants or crops.

Expression of CD63 in Lung Tissue of Guinea Pigs Dying of Anaphylactic Shock

Abstract

Objective To study the protein expression of cluster of differentiation 63 （CD63） in lung tissues of guinea pigs that died of anaphylactic shock and discuss the diagnostic value of CD63 for death from anaphylactic shock. Methods Twenty guinea pigs were randomly divided into control group, anaphylactic shock immediate death group, cold storage group （4 ℃ for 48 h） and frozen group （-20 ℃ for 7 d）. The animal model of guinea pigs that died of anaphylactic shock was established with human mixed serum injection. The expression changes of CD63 protein and CD63 mRNA in lung tissues were detected by hematoxylin-eosin （HE） staining, immunohistochemical staining, Western blotting, enzyme-linked immunosorbent assay （ELISA） and real-time RT-PCR. Results HE staining results showed congestion, and edema of lung tissues, and eosinophil infiltration in the anaphylactic shock groups. Western blotting analysis results showed that the expression of CD63 protein in the lung tissues of guinea pigs that died of anaphylactic shock was significantly higher than that in the control group （P<0.05）. Comparison between the anaphylactic shock groups was made, and the differences had no statistical significance. The results of immunohistochemical staining and real-time RT-PCR were consistent with that of Western blotting. ELISA results showed that CD63 protein expression in the immediate death group was higher than that in the control group （P<0.05）. Conclusion The expression of CD63 protein and CD63 mRNA in the lung tissues of guinea pigs that died of anaphylactic shock is significantly enhanced. Animal carcasses which were put in cold storage for 48 h and frozen for 7 d do not affect the examination of the above indicators. CD63 protein is expected to become an auxiliary diagnostic indicator of death from anaphylactic shock.

[Trend of mortality and decomposition on malignant tumors in Shandong province, 1970-2013]

Objective: To describe the mortality trend of major malignant tumors in Shandong province, from 1970 to 2013. Methods: Data related to cancer mortality were obtained from the Shandong Death Registration System and three nationwide retrospective cause-of-death surveys. Trends of overall mortality and major causes of death were described using the indicators as: mortality rates and age-standardized mortality rates, through comparing the three large-scale mortality surveys in Shandong province. Difference decomposing method was applied to estimate the contribution of demographic and non-demographic factors for the change of mortality. Results: From 1970 to 2013, the crude mortality rate of malignant tumors in Shandong was increasing. The age standard mortality rate was increasing and then decreasing. The composition of cancer deaths in the all-cause-deaths was seen increasing and then decreasing as well. Both demographic and non-demographic factors contributed to the increase of crude cancer mortality rate. With the gradual increase of the proportion of population, its role exceeded the non-demographic factors. The age-standardized mortality rate of malignant tumors in 2011-2013 was lower than that in 2004-2005. Lung cancer mortality rose from the fifth to the first place, with an increase of 6.81 times from 1970-1974 to 2011-2013. Ranking of gastric cancer mortality dropped from first to the third place, with esophageal cancer dropped from second to the fourth. After adjusted by China's standard population in 1964, the mortality rate of lung cancer was still rapidly increasing, but the age-standardized mortality rates of esophageal cancer was gradually decreasing. The crude and age-standardized mortality rates of cervical cancer showed a rapid downward trend, reduced 87.00% and 93.00% respectively from 1970-1974 to 2011-2013. Conclusions: Malignant tumors were still major threats to the residents of Shandong province. The changing trend of different malignant tumors presented an inconsistent nature which called for different intervention strategies be carried out, accordingly.

Quantum Criticality of the Ising-like Screw Chain Antiferromagnet SrCo_{2}V_{2}O_{8} in a Transverse Magnetic Field

The quantum criticality of an Ising-like screw chain antiferromagnet SrCo_{2}V_{2}O_{8}, with a transverse magnetic field applied along the crystalline a axis, is investigated by ultralow temperature NMR measurements. The Néel temperature is rapidly and continuously suppressed by the field, giving rise to a quantum critical point (QCP) at H_{C_{1}}≈7.03  T. Surprisingly, a second QCP at H_{C_{2}}≈7.7  T featured with gapless excitations is resolved from both the double-peak structure of the field-dependent spin-lattice relaxation rate 1/^{51}T_{1} at low temperatures and the weakly temperature-dependent 1/^{51}T_{1} at this field. Our data, combined with numerical calculations, suggest that the induced effective staggered transverse field significantly lowers the critical fields, and leads to an exposed QCP at H_{C_{2}}, which belongs to the one-dimensional transverse-field Ising universality.