Transcriptome and Metabolome Analyses Provide Insight into the Glucose-Induced Adipogenesis in Porcine Adipocytes.

Glucose is a major energy substrate for porcine adipocytes and also serves as a regulatory signal for adipogenesis and lipid metabolism. In this study, we combined transcriptome and metabolome analyses to reveal the underlying regulatory mechanisms of high glucose (HG) on adipogenesis by comparing differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) identified in porcine adipocytes. Results showed that HG (20 mmol/L) significantly increased fat accumulation in porcine adipocytes compared to low glucose (LG, 5 mmol/L). A total of 843 DEGs and 365 DAMs were identified. Functional enrichment analyses of DEGs found that multiple pathways were related to adipogenesis, lipid metabolism, and immune-inflammatory responses. PPARγ, C/EBPα, ChREBP, and FOS were identified as the key hub genes through module 3 analysis, and PPARγ acted as a central regulator by linking genes involved in lipid metabolism and immune-inflammatory responses. Gene-metabolite networks found that PPARγ-13-HODE was the most important interaction relationship. These results revealed that PPARγ could mediate the cross-talk between adipogenesis and the immune-inflammatory response during adipocyte maturation. This work provides a comprehensive view of the regulatory mechanisms of glucose on adipogenesis in porcine adipocytes.

High-quality chromosome-level genome assembly and multi-omics analysis of rosemary (Salvia rosmarinus) reveals new insights into the environmental and genome adaptation.

High-quality genome of rosemary (Salvia rosmarinus) represents a valuable resource and tool for understanding genome evolution and environmental adaptation as well as its genetic improvement. However, the existing rosemary genome did not provide insights into the relationship between antioxidant components and environmental adaptability. In this study, by employing Nanopore sequencing and Hi-C technologies, a total of 1.17 Gb (97.96%) genome sequences were mapped to 12 chromosomes with 46 121 protein-coding genes and 1265 non-coding RNA genes. Comparative genome analysis reveals that rosemary had a closely genetic relationship with Salvia splendens and Salvia miltiorrhiza, and it diverged from them approximately 33.7 million years ago (MYA), and one whole-genome duplication occurred around 28.3 MYA in rosemary genome. Among all identified rosemary genes, 1918 gene families were expanded, 35 of which are involved in the biosynthesis of antioxidant components. These expanded gene families enhance the ability of rosemary adaptation to adverse environments. Multi-omics (integrated transcriptome and metabolome) analysis showed the tissue-specific distribution of antioxidant components related to environmental adaptation. During the drought, heat and salt stress treatments, 36 genes in the biosynthesis pathways of carnosic acid, rosmarinic acid and flavonoids were up-regulated, illustrating the important role of these antioxidant components in responding to abiotic stresses by adjusting ROS homeostasis. Moreover, cooperating with the photosynthesis, substance and energy metabolism, protein and ion balance, the collaborative system maintained cell stability and improved the ability of rosemary against harsh environment. This study provides a genomic data platform for gene discovery and precision breeding in rosemary. Our results also provide new insights into the adaptive evolution of rosemary and the contribution of antioxidant components in resistance to harsh environments.

Arsenite-Induced Drug-Drug Interactions in Rats.

Arsenite is an important heavy metal. Some Chinese traditional medicines contain significant amounts of arsenite. The aim of this study was to investigate subacute exposure of arsenite on activities of cytochrome P450 enzymes and pharmacokinetic behaviors of drugs in rats. Midazolam, tolbutamide, metoprolol, omeprazole, caffeine, and chlorzoxazone, the probe substrates for cytochrome P450 (CYP) s3A, 2C6, 2D, 2C11, 1A, and 2E, were selected as probe drugs for the pharmacokinetic study. Significant decreases in areas under the curves of probe substrates were observed in rats after consecutive 30-day exposure to As at 12 mg/kg. Microsomal incubation study showed that the subacute exposure to arsenite resulted in little change in effects on the activities of P450 enzymes examined. However, everted gut sac study demonstrated that such exposure induced significant decreases in intestinal absorption of these drugs by both passive diffusion and carrier-mediated transport. In addition, in vivo study showed that the arsenite exposure decreased the rate of peristaltic propulsion. The decreases in intestinal permeability of the probe drugs and peristaltic propulsion rate most likely resulted in the observed decreases in the internal exposure of the probe drugs. Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. SIGNIFICANCE STATEMENT: Exposure to arsenite may lead to the reduction of the efficiencies of pharmaceutical agents coadministered resulting from the observed drug-drug interactions. The present study, we found that P450 enzyme probe drug exposure was reduced in arsenic-exposed animals (areas under the curve) and the intestinal absorption of the drug was reduced in the animals. Subacute arsenic exposure tends to cause damage to intestinal function, which leads to reduced drug absorption.

Identification of an Epoxide Metabolite of Amitriptyline In Vitro and In Vivo.

Amitriptyline (ATL), a tricyclic antidepressant, has been reported to cause various adverse effects, particularly hepatotoxicity. The mechanisms of ATL-induced hepatotoxicity remain unknown. The study was performed to identify the olefin epoxidation metabolite of ATL and determine the possible toxicity mechanism. Two glutathione (GSH) conjugates (M1 and M2) and two N-acetylcysteine (NAC) conjugates (M3 and M4) were detected in rat liver microsomal incubations supplemented with GSH and NAC, respectively. Moreover, M1/M2 and M3/M4 were respectively found in ATL-treated rat primary hepatocytes and in bile and urine of rats given ATL. Recombinant P450 enzyme incubations demonstrated that CYP3A4 was the primary enzyme involved in the olefin epoxidation of ATL. Treatment of hepatocytes with ATL resulted in significant cell death. Inhibition of CYP3A attenuated the susceptibility to the observed cytotoxicity of ATL. The metabolic activation of ATL most likely participates in the cytotoxicity of ATL.

H. pylori infection and osteoporosis: a large-scale observational and mendelian randomization study.

PURPOSE: There is controversy concerning the relationship between Helicobacter pylori (H. pylori) infection and osteoporosis. This study is to examine the causal relationship between H. pylori infection and osteoporosis and to analyze the potential mechanism underlying the relationship. METHODS: The clinical data of H. pylori infection and bone mineral density from patients or physical examiner with good general condition in our hospital between September 2019 and September 2020 were retrospectively collected. The relationship between H. pylori infection and osteoporosis was compared and analyzed, using logistic regression to examine the potential mechanism underlying the association. To investigate the causal effects of H. pylori infection and osteoporosis, we conducted a two-sample bidirectional Mendelian randomization (MR) analysis. RESULTS: A total of 470 patients were positive for H. pylori, with a detection rate of 52.22%. It was found that age, SBP, FPG, DBP, ALB, LDL-C, hs-CRP, and OC were positively correlated with osteoporosis, while negative correlations were observed with BMI, LYM, ALB, TP, TG, HDL-C, SCr, UA, and VitD. After stratified analysis of sex and age, it was found that there was a significant correlation between H. pylori infection and osteoporosis. The levels of SBP, ALP, FPG, LDL-C, hs-CRP, and OC in both H. pylori-positive group and osteoporosis group were higher than those in the H. pylori-negative group while the levels of BMI, ALB, TP, HDL-C, SCr, UA, and VitD in the positive group were significantly lower than those in the negative group. Logistic regression analyses with gender and age showed that ALB, FPG, HDL-C, and VitD were common risk factors for osteoporosis and H. pylori infection. In the MR analysis, the IVW results found a positive effect of H. pylori infection on osteoporosis (OR = 1.0017, 95% CI: 1.0002-1.0033, P = 0.0217). Regarding the reverse direction analysis, there was insufficient evidence to prove the causal effects of osteoporosis on H. pylori infection. CONCLUSION: Our study provides evidence for causal effects of H. pylori infection on osteoporosis. H. pylori may affect osteoporosis through serum albumin, high-density lipoprotein, fasting blood glucose and vitamin D.

Recent Advances in Mass Spectrometry-Based Spatially Resolved Molecular Imaging of Drug Disposition and Metabolomics.

Mass spectrometric imaging is a nontargeted, tag-free, high-throughput, and highly responsive analytical approach. The highly accurate molecular visualization detection technology enables qualitative and quantitative analyses of biologic tissues or cells scanned by mass spectrometry in situ, extracting known and unknown multiple compounds, and simultaneously assessing relative contents of targeting molecules by monitoring their molecular ions and pinpointing the spatial locations of those molecules distributed. Five mass spectrometric imaging techniques and their characteristics are introduced in the review, including matrix-assisted laser desorption ionization mass spectrometry, secondary ion mass spectrometry, desorption electrospray ionization mass spectrometry, laser ablation electrospray ionization mass spectrometry, and laser ablation inductively coupled plasma mass spectrometry. The mass spectrometry-based techniques provide the possibility for spatial metabolomics with the capability of high throughput and precision detection. The approaches have been widely employed to spatially image not only metabolome of endogenous amino acids, peptides, proteins, neurotransmitters, and lipids but also the disposition of exogenous chemicals, such as pharmaceutical agents, environmental pollutants, toxicants, natural products, and heavy metals. The techniques also provide us with spatial distribution imaging of analytes in single cells, tissue microregions, organs, and whole animals. SIGNIFICANCE STATEMENT: The review article includes an overview of five commonly used mass spectrometers for spatial imaging and describes the advantages and disadvantages of each. Examples of the technology applications cover drug disposition, diseases, and omics. Technical aspects of relative and absolute quantification by mass spectrometric imaging and challenges for future new applications are discussed as well. The reviewed knowledge may benefit the development of new drugs and provide a better understanding of biochemical processes related to physiology and diseases.

Characterization and fine mapping analysis of a major stable QTL qKnps-4A for kernel number per spike in wheat.

KEY MESSAGE: A major stable QTL for kernel number per spike was narrowed down to a 2.19-Mb region containing two potential candidate genes, and its effects on yield-related traits were characterized. Kernel number per spike (KNPS) in wheat is a key yield component. Dissection and characterization of major stable quantitative trait loci (QTLs) for KNPS would be of considerable value for the genetic improvement of yield potential using molecular breeding technology. We had previously reported a major stable QTL controlling KNPS, qKnps-4A. In the current study, primary fine-mapping analysis, based on the primary mapping population, located qKnps-4A to an interval of approximately 6.8-Mb from 649.0 to 655.8 Mb on chromosome 4A refering to 'Kenong 9204' genome. Further fine-mapping analysis based on a secondary mapping population narrowed qKnps-4A to an approximately 2.19-Mb interval from 653.72 to 655.91 Mb. Transcriptome sequencing, gene function annotation analysis and homologous gene related reports showed that TraesKN4A01HG38570 and TraesKN4A01HG38590 were most likely to be candidate genes of qKnps-4A. Phenotypic analysis based on paired near-isogenic lines in the target region showed that qKnps-4A increased KNPS mainly by increasing the number of central florets per spike. We also evaluated the effects of qKnps-4A on other yield-related traits. Moreover, we dissected the QTL cluster of qKnps-4A and qTkw-4A and proved that the phenotypic effects were probably due to close linkage of two or more genes rather than pleiotropic effects of a single gene. This study provides molecular marker resource for wheat molecular breeding designed to improve yield potential, and lay the foundation for gene functional analysis of qKnps-4A.

Biphenylene network as sodium ion battery anode material.

Sodium ion batteries possess several advantages for large-scale energy storage, such as low cost and enhanced safety. However, graphite or other anode materials are not satisfactory because the large radius of Na+ hinders their embedding and removal in the charge and discharge processes. Recently, a biphenylene network (BPN), a two-dimensional (2D) carbon allotrope, has been synthesized. In this paper, we reveal the potential possibility of BPN as a Na storage material. The theoretical results indicate the advantages of BPN as a sodium battery anode. The maximum specific capacity (413 mA h g-1) is larger than that of the graphite-Li system (372 mA h g-1). With low Na+ diffusion barrier (<0.6 eV) and small volume expansion in the charging process (∼26%), BPN presents superiority to the graphite-Na system. Our findings show new insights into Na storage in BPN and provide guidance for the use of a BPN anode in sodium ion batteries.

Nonlinear Vibration Control Experimental System Design of a Flexible Arm Using Interactive Actuations from Shape Memory Alloy.

The flexible arm easily vibrates due to its thin structural characteristics, which affect the operation accuracy, so reducing the vibration of the flexible arm is a significant issue. Smart materials are very widely used in the research topic of vibration suppression. Considering the hysteresis characteristic of the smart materials, based on previous simulation research, this paper proposes an experimental system design of nonlinear vibration control by using the interactive actuation from shape memory alloy (SMA) for a flexible arm. The experiment system was an interactive actuator-sensor-controller combination. The vibration suppression strategy was integrated with an operator-based vibration controller, a designed integral compensator and the designed n-times feedback loop. In detail, a nonlinear vibration controller based on operator theory was designed to guarantee the robust stability of the flexible arm. An integral compensator based on an estimation mechanism was designed to optimally reduce the displacement of the flexible arm. Obtaining the desired tracking performance of the flexible arm was a further step, by increasing the n-times feedback loop. From the three experimental cases, when the vibration controller was integrated with the designed integral compensator, the vibration displacement of the flexible arm was much reduced compared to that without the integral compensator. Increasing the number of n-times feedback loops improves the tracking performance. The desired vibration control performance can be satisfied when n tends to infinity. The conventional PD controller stabilizes the vibration displacement after the 7th vibration waveform, while the vibration displacement approaches zero after the 4th vibration waveform using the proposed vibration control method, which is proved to be faster and more effective in controlling the flexible arm's vibration. The experimental cases verify the effectiveness of the proposed interactive actuation vibration control approach. It is observed from the experimental results that the vibration displacement of the flexible arm becomes almost zero within less time and with lower input power, compared with a traditional controller.

A Survey of Helicobacter pylori Antibiotic-Resistant Genotypes and Strain Lineages by Whole-Genome Sequencing in China.

Antibiotic resistance is the most important factor leading to failed Helicobacter pylori eradication therapy, and personalized treatment based on antibiotic susceptibility is becoming increasingly important. To strengthen the understanding of antibiotic genotypic resistance of H. pylori and identify new antibiotic resistance loci, in this study, we identified phenotypic resistance information for 60 clinical isolates and compared the concordance of phenotypic and genotypic resistance using whole-genome sequencing (WGS). Clarithromycin and levofloxacin genotypic resistance was in almost perfect concordance with phenotypic resistance, with kappa coefficients of 0.867 and 0.833, respectively. All strains with the R16H/C mutation and truncation in rdxA were metronidazole resistant, with 100% specificity. For other genes of concern, at least one phenotypically sensitive strain had a previous mutation related to antibiotic resistance. Moreover, we found that the A1378G mutation of HP0399 and the A149G mutation of FabH might contribute to tetracycline resistance and multidrug resistance, respectively. Overall, the inference of resistance to clarithromycin and levofloxacin from genotypic resistance is reliable, and WGS has been very helpful in discovering novel H. pylori resistance loci. In addition, WGS has also enhanced our study of strain lineages, providing new ways to understand resistance information and mechanisms.

Large-scale analysis of protein crotonylation reveals its diverse functions in Pinellia ternata.

BACKGROUND: Pinellia ternata is an important traditional medicine in China, and its growth is regulated by the transcriptome or proteome. Lysine crotonylation, a newly identified and important type of posttranslational modification, plays a key role in many aspects of cell metabolism. However, little is known about its functions in Pinellia ternata. RESULTS: In this study, we generated a global crotonylome analysis of Pinellia ternata and examined its overlap with lysine succinylation. A total of 2106 crotonylated sites matched on 1006 proteins overlapping in three independent tests were identified, and we found three specific amino acids surrounding crotonylation sites in Pinellia ternata: KcrF, K***Y**Kcr and Kcr****R. Gene Ontology (GO) and KEGG pathway enrichment analyses showed that two crucial alkaloid biosynthesis-related enzymes and many stress-related proteins were also highly crotonylated. Furthermore, several enzymes participating in carbohydrate metabolism pathways were found to exhibit both lysine crotonylation and succinylation modifications. CONCLUSIONS: These results indicate that lysine crotonylation performs important functions in many biological processes in Pinellia ternata, especially in the biosynthesis of alkaloids, and some metabolic pathways are simultaneously regulated by lysine crotonylation and succinylation.

Selective CO2 reduction on topological Chern magnet TbMn6Sn6.

As a new type of topological magnet, TbMn6Sn6 has a planar Mn kagome lattice with out-of-plane magnetic moments. Previous studies have found spin-polarized Chern gapped Dirac fermions in TbMn6Sn6, which are advantageous to topological catalysis. In this study, we theoretically demonstrate that the TbMn6Sn6 (001) surface is favorable for CO2 reduction. The stability of different surface types is investigated, and then the reaction paths of CO2 reduction on the surfaces are revealed to prove that the product is selective. This work reveals the effect of magnetic topological materials on CO2 reduction.

CO2 reduction on single-atom Ir catalysts with chemical functionalization.

As promising catalytic systems, single-atom catalysts (SACs) demonstrate improved catalytic performance for electrochemical reactions. However, the pinning of metal atoms on surfaces usually depends on the adsorption on defects. In this study, defect-free functionalization by attaching IrX3 (X = F or Cl) complexes on the MoS2 monolayer is theoretically demonstrated. The ligand-based method offers a damage-free route for stabilizing SACs on 2D materials. We demonstrate the CO2 reduction process on MoS2-IrX3 with a small change in free energy and a low onset potential. The d6 shell of Ir acts as a molecular joint with universal orbital orientations, which benefits the adsorption of different reaction intermediates. This study shows the superiority of defect-free functionalization of 2D materials using SAC-ligand complexes.

Circular RNA circVMA21 ameliorates lipopolysaccharide (LPS)-induced acute kidney injury by targeting the miR-199a-5p/NRP1 axis in sepsis.

BACKGROUND: Sepsis is a serious and elusive syndrome caused by infection, with high mortality worldwide. Circular RNAs vacuolar ATPase assembly factor (circVMA21) has been reported to be related to the inflammatory damages in sepsis. This study is designed to explore the role and mechanism of circVMA21 in the lipopolysaccharide (LPS)-induced cell injury in sepsis. METHODS: Cell viability and apoptosis were detected by CCK-8, and flow cytometry assays. CircVMA21, microRNA-199a-5p (miR-199a-5p), and Neuropilin-1 (NRP1) level were determined by RT-qPCR. Protein levels of Bcl-2, Bax, cleaved-caspase 3, and NRP1 were examined by Western blot assay. IL-1ß, IL-6, and TNF-α were detected using ELISA. Superoxide Dismutase (SOD) and glutathione (GSH) were measured by the special kits. The binding relationship between miR-199a-5p and circVMA21 or NRP1 was predicted by Starbase 3.0 and then verified by a dual-luciferase reporter and RIP assays. RESULTS: CircVMA21 and NRP1 were decreased, and miR-199a-5p was increased in LPS-induced THP-1 cells. Moreover, circVMA21 overexpression could repress LPS-mediated cell viability, apoptosis, inflammation, and oxidative stress in THP-1 cells. The mechanical analysis suggested that circVMA21 regulated NRP1 expression through sponging miR-199a-5p. CONCLUSION: CircVMA21 upregulation could attenuate LPS-triggered THP-1 cell injury through modulating the miR-199a-5p/NRP1 axis, hinting an underlying therapeutic strategy for sepsis patients.

Genetic dissection of an allotetraploid interspecific CSSLs guides interspecific genetics and breeding in cotton.

BACKGROUND: The low genetic diversity of Upland cotton limits the potential for genetic improvement. Making full use of the genetic resources of Sea-island cotton will facilitate genetic improvement of widely cultivated Upland cotton varieties. The chromosome segments substitution lines (CSSLs) provide an ideal strategy for mapping quantitative trait loci (QTL) in interspecific hybridization. RESULTS: In this study, a CSSL population was developed by PCR-based markers assisted selection (MAS), derived from the crossing and backcrossing of Gossypium hirsutum (Gh) and G. barbadense (Gb), firstly. Then, by whole genome re-sequencing, 11,653,661 high-quality single nucleotide polymorphisms (SNPs) were identified which ultimately constructed 1211 recombination chromosome introgression segments from Gb. The sequencing-based physical map provided more accurate introgressions than the PCR-based markers. By exploiting CSSLs with mutant morphological traits, the genes responding for leaf shape and fuzz-less mutation in the Gb were identified. Based on a high-resolution recombination bin map to uncover genetic loci determining the phenotypic variance between Gh and Gb, 64 QTLs were identified for 14 agronomic traits with an interval length of 158 kb to 27 Mb. Surprisingly, multiple alleles of Gb showed extremely high value in enhancing cottonseed oil content (SOC). CONCLUSIONS: This study provides guidance for studying interspecific inheritance, especially breeding researchers, for future studies using the traditional PCR-based molecular markers and high-throughput re-sequencing technology in the study of CSSLs. Available resources include candidate position for controlling cotton quality and quantitative traits, and excellent breeding materials. Collectively, our results provide insights into the genetic effects of Gb alleles on the Gh, and provide guidance for the utilization of Gb alleles in interspecific breeding.

Orexin A associates with inflammation by interacting with OX1R/OX2R receptor and activating prepro-Orexin in cancer tissues of gastric cancer patients.

OBJECTIVE: Gastric cancer (GC) has been become the second leading cause for cancer-associated death. This study aimed to investigate Orexin A levels and associated receptors in tumor tissues of GC patients. PATIENTS AND METHODS: Forty-six consecutive gastric cancer patients (GC, n=46) and 13 chronic atrophic gastritis patients (CAG, n=13) were recruited. Meanwhile, 18 health individuals visiting Medical Examination Department were involved as control (N group, n=18). ELISA was used to examine Orexin A concentration. Immunohistochemistry assay was used to examine OX1R and OX2R. HE staining was applied to evaluate inflammation. qRT-PCR was employed to detect OX1R, OX2R, prepro-Orexin mRNAs. Serum Helicobacter pylori (H. pylori) infection was measured. RESULTS: Orexin A expression in GC patients was significantly up-regulated compared to N group and CAG group (p<0.05). Orexin A expression was increased in CAG group compared to N group (p<0.05). Gastric cancer tissues exhibited significantly obvious inflammation compared to N group and CAG group (p<0.05). OX1R and OX2R expressions were significantly down-regulated in GC group compared to N group and CAG group (p<0.05). OX1R and OX2R were lower significantly in GC group compared to CAG group (p<0.05). Prepro-Orexin was significantly depleted in tumor tissues of GC group compared to N group and CAG group (p<0.05). Orexin A expression was un-associated with gender, age and differential grades (p>0.05). CAG and GC patients demonstrated higher H. pylori infection rates. CONCLUSION: Orexin A was associated with inflammation by interacting with OX1R/OX2R receptor and activating prepro-Orexin in tumor tissues of gastric cancer patients.

The Therapeutic Effect of ICAM-1-Overexpressing Mesenchymal Stem Cells on Acute Graft-Versus-Host Disease.

BACKGROUND/AIMS: Mesenchymal stem cells (MSCs) do not readily migrate to appropriate sites, and this creates a major obstacle for their use in the treatment of graft-versus-host disease (GVHD). Intercellular adhesion molecule-1 (ICAM-1) can guide the homing of various immune cells to the proper anatomical location within secondary lymphoid organs (SLOs), which are the major niches for generating immune responses or tolerance. MSCs rarely migrate to SLOs after intravenous infusion, and are constitutively low expression of ICAM-1. So in our previous work, ICAM-1 was engineered into a murine MSC line C3H10T1/2 by retrovirus transfection system (ICAM-1MSCs). Here, we hypothesized that ICAM-1highMSCs may significantly improve their immunomodulatory effect. METHODS: We used different co-culture methods combined with real-time PCR and flow cytometry to evaluate ICAM-1highMSCs immunomodulatory effect on dendritic cells (DCs) and T cells in vitro and in vivo. MSCs were labeled with carboxyfluorescein diacetate succinimidylester (CFSE) to detect its distribution in mouse model. RESULTS: Our in vitro analyses revealed ICAM-1 MSCs could suppress DCs maturation according to co-culture methods and suppress the T cell immune response according to the mixed lymphocyte response (MLR) and lymphoblast transformation test (LTT) tests. We found that infusion of ICAM-1highMSCs potently prolonged the survival of GVHD mouse model. The infused ICAM-1highMSCs migrate to SLOs in vivo, and suppressed DCs maturation, suppressed CD4+ T cell differentiation to Th1 cells, and increased the ratios of Treg cells. CONCLUSIONS: Taken together, these data demonstrate that ICAM-1highMSCs had an enhanced immunosuppressive effect on DCs and T cells, which may help explain the protective effect in a GVHD model. This exciting therapeutic strategy may improve the clinical efficacy of MSC-based therapy for GVHD.

Phase control of highly efficient four-wave mixing in a six-level tripod atomic system.

We investigate theoretically an enhancement of four-wave mixing (FWM) process in phase-dependent double electromagnetically induced transparency (EIT) six-level atomic media. It is shown, owing to the multiphoton destructive interference, that the conversion efficiency of FWM can be enhanced by manipulating the relative phase of the applied fields in this ultraslow propagation regime. Moreover, we also find that the conversion efficiency is amplified with the presence of the microwave field in comparison with the previous six-level scheme [Phys. Rev. A76, 043809 (2007)PLRAAN1050-294710.1103/PhysRevA.76.043809].

Multiple spontaneously generated coherence and phase control of optical bistability and multistability in a tripod four-level atomic medium.

Optical bistability (OB) and optical multistability (OM) behaviors induced by multiple spontaneously generated coherence (SGC) are investigated theoretically in a tripod four-level atomic scheme. It is found that OB or OM is sensitive to the SGC effects, and the thresholds of OB can be controlled via changing the strength of multiple SGC or the relative phases of the applied fields. In addition, we can switch OB to OM by adjusting the twofold relative phases of the applied fields or vice versa.

Subhaplogroup D4b1 enhances the risk of cervical cancer initiation: A case-control study in southern China.

AIM: To investigate whether mitochondrial DNA (mtDNA) background (haplogroup) is associated with cervical cancer in patients in southern China. METHODS: A case-control study of 150 patients with cervical cancer and 217 geographically matched controls was conducted in Wenzhou, a southern Chinese city in the Zhejiang province. DNA from peripheral blood was extracted and sequenced. Sequences were aligned to the mtDNA revised Cambridge Reference Sequence (GenBank number NC_012920) to determine mtDNA single nucleotide polymorphisms (SNPs) and haplogroups. RESULTS: We found that both M and N haplogroups and their diagnostic SNPs (A10398G and C10400T) are not associated with the risk of cervical cancer. However, individuals with haplogroup D4b1/D4b1*, an M subhaplogroup, exhibited an increased risk of cervical cancer (odds ratio [OR] = 1.034; 95% confidence interval [CI] 1.004, 1.066; P = 0.011/OR =1.027; 95% CI 1.001, 1.055; P = 0.027). Individuals with SNPs C10181T/A10136G (OR =1.034; 95% CI 1.004, 1.066; P = 0.011/OR =1.027; 95% CI 1.001, 1.055; P = 0.027) were more susceptible to cervical cancer than individuals without. Furthermore, we determined that mtDNA background is not associated with the progression of cervical cancer. CONCLUSIONS: Our results indicate that mtDNA haplogroups play a role in cervical cancer initiation.