In planta imaging of pyridine nucleotides using second-generation fluorescent protein biosensors.

Redox changes of pyridine nucleotides in cellular compartments are highly dynamic and their equilibria are under the influence of various reducing and oxidizing reactions. To obtain spatiotemporal data on pyridine nucleotides in living plant cells, typical biochemical approaches require cell destruction. To date, genetically encoded fluorescent biosensors are considered to be the best option to bridge the existing technology gap, as they provide a fast, accurate, and real-time readout. However, the existing pyridine nucleotides genetically encoded fluorescent biosensors are either sensitive to pH change or slow in dissociation rate. Herein, we employed the biosensors which generate readouts that are pH stable for in planta measurement of NADH/NAD+ ratio and NADPH level. We generated transgenic Arabidopsis lines that express these biosensors in plastid stroma and cytosol of whole plants and pollen tubes under the control of CaMV 35S and LAT52 promoters, respectively. These transgenic biosensor lines allow us to monitor real-time dynamic changes in NADH/NAD+ ratio and NADPH level in the plastids and cytosol of various plant tissues, including pollen tubes, root hairs, and mesophyll cells, using a variety of fluorescent instruments. We anticipate that these valuable transgenic lines may allow improvements in plant redox biology studies.

Genome-wide identification of WRKY transcription factors in Casuarina equisetifolia and the function analysis of CeqWRKY11 in response to NaCl/NaHCO3 stresses.

BACKGROUND: Casuarina equisetifolia (C. equisetifolia) is a woody species with many excellent features. It has natural resistance against drought, salt and saline-alkali stresses. WRKY transcription factors (TFs) play significant roles in plant response to abiotic stresses, therefore, molecular characterization of WRKY gene family under abiotic stresses holds great significance for improvement of forest trees through molecular biological tools. At present, WRKY TFs from C. equisetifolia have not been thoroughly studied with respect to their role in salt and saline-alkali stresses response. The current study was conducted to bridge the same knowledge gap. RESULTS: A total of 64 WRKYs were identified in C. equisetifolia and divided into three major groups i.e. group I, II and III, consisting of 10, 42 and 12 WRKY members, respectively. The WRKY members in group II were further divided into 5 subgroups according to their homology with Arabidopsis counterparts. WRKYs belonging to the same group exhibited higher similarities in gene structure and the presence of conserved motifs. Promoter analysis data showed the presence of various response elements, especially those related to hormone signaling and abiotic stresses, such as ABRE (ABA), TGACG (MeJA), W-box ((C/T) TGAC (T/C)) and TC-rich motif. Tissue specific expression data showed that CeqWRKYs were mainly expressed in root under normal growth conditions. Furthermore, most of the CeqWRKYs were up-regulated by NaCl and NaHCO3 stresses with few of WRKYs showing early responsiveness to both stresses while few others exhibiting late response. Although the expressions of CeqWRKYs were also induced by cold stress, the response was delayed compared with other stresses. Transgenic C. equisetifolia plants overexpressing CeqWRKY11 displayed lower electrolyte leakage, higher chlorophyll content, and enhanced tolerance to both stresses. The higher expression of abiotic stress related genes, especially CeqHKT1 and CeqPOD7, in overexpression lines points to the maintenance of optimum Na+/K+ ratio, and ROS scavenging as possible key molecular mechanisms underlying salt stress tolerance. CONCLUSIONS: Our results show that CeqWRKYs might be key regulators of NaCl and NaHCO3 stresses response in C. equisetifolia. In addition, positive correlation of CeqWRKY11 expression with increased stress tolerance in C. equisetifolia encourages further research on other WRKY family members through functional genomic tools. The best candidates could be incorporated in other woody plant species for improving stress tolerance.

Progress in Pathological and Therapeutic Research of HIV-Related Neuropathic Pain.

HIV-related neuropathic pain (HRNP) is a neurodegeneration that gradually develops during the long-term course of acquired immune deficiency syndrome (AIDS) and manifests as abnormal sock/sleeve-like symmetrical pain and nociceptive hyperalgesia in the extremities, which seriously reduces patient quality of life. To date, the pathogenesis of HRNP is not completely clear. There is a lack of effective clinical treatment for HRNP and it is becoming a challenge and hot spot for medical research. In this study, we conducted a systematic review of the progress of HRNP research in recent years including (1) the etiology, classification and clinical symptoms of HRNP, (2) the establishment of HRNP pathological models, (3) the pathological mechanisms underlying HRNP from three aspects: molecules, signaling pathways and cells, (4) the therapeutic strategies for HRNP, and (5) the limitations of recent HRNP research and the future research directions and prospects of HRNP. This detailed review provides new and systematic insight into the pathological mechanism of HRNP, which establishes a theoretical basis for the future exploitation of novel target drugs. HIV infection, antiretroviral therapy and opioid abuse contribute to the etiology of HRNP with symmetrical pain in both hands and feet, allodynia and hyperalgesia. The pathogenesis involves changes in cytokine expression, activation of signaling pathways and neuronal cell states. The therapy for HRNP should be patient-centered, integrating pharmacologic and nonpharmacologic treatments into multimodal intervention.

Comparison of pulsed-field gel electrophoresis and a novel amplified intergenic locus polymorphism method for molecular typing of Campylobacter jejuni.

Campylobacter is regarded as the leading cause of zoonotic diseases and Campylobacter jejuni (C. jejuni) is one of the predominant pathogenic species. To track C. jejuni infections, various genotyping methods have been used. In this study, amplified intergenic locus polymorphism (AILP) was used to type C. jejuni for the first time. To confirm its feasibility, pulsed-field gel electrophoresis (PFGE) was performed as a control, and the results obtained by the AILP and PFGE methods were compared. Fifty-one isolates were resolved into 34 and 29 different genotypes with Simpson's indices of 0.976 and 0.967 using the AILP and PFGE methods, respectively. The adjusted Rand coefficient of the two approaches was as high as 0.845. In summary, the data showed that the two genotyping methods were similar for discriminating isolates and were both appropriate methods to distinguish whether two isolates were indistinguishable, but the AILP was faster and less costly than PFGE. Therefore, the AILP is a reliable, rapid, and highly discriminative method to genotype C. jejuni collected from poultry meat, which is helpful to effectively monitor C. jejuni.

MOF-Derived In2O3 Microrod-Decorated MgIn2S4 Nanosheets: Z-Scheme Heterojunction for Efficient Photocatalytic Degradation of Tetracycline.

The construction of Z-scheme heterostructures using matching band semiconductors is an effective strategy for producing highly efficient photocatalysts. In this study, MgIn2S4(MIS) was grown in situ on In2O3 microrods created with an In-based MOF material (In-MIL-68) as a template to successfully establish a unique MIS-In2O3 heterojunction with a well-matched Z-scheme interface charge transfer channel. Tetracycline (TC) as a typical antibiotic was chosen as the target pollutant to evaluate the photocatalytic activity. After 120 min of visible light irradiation, the MIS-In2O3-(10:1) material had the greatest photocatalytic degradation activity of tetracycline with 96.55%, which was 2.39 and 4.26 times that of MIS and In2O3, respectively. The improved photocatalytic activity is attributed to the in situ growth of MIS on In2O3, forming a Z-scheme heterojunction at the interface, which not only increases the specific surface area, exposes the abundant active site, and improves light utilization but also facilitates the migration and separation of photogenic carriers. The photocatalytic degradation products of TC were detected by liquid chromatography-mass spectrometry (LC-MS), and a preliminary degradation pathway was proposed. Radical capture experiments and ESR analysis confirmed that the main active species were holes (h+), superoxide radicals (•O2-), and superoxide and hydroxyl radicals (•OH). Finally, combined with band position analysis, this study proposes a direct Z-scheme heterojunction mechanism to improve the photocatalytic degradation of tetracycline in MIS under visible light.

Rapid Genotyping of Campylobacter coli Strains from Poultry Meat by PFGE, Sau-PCR, and fla-DGGE.

The genotyping of Campylobacter coli was done using three methods, pulsed-field gel electrophoresis (PFGE), Sau-polymerase chain reaction (Sau-PCR), and denaturing gradient gel electrophoresis assay of flagellin gene (fla-DGGE) and the characteristics of these assays were compared. The results showed that a total of 53 strains of C. coli were isolated from chicken and duck samples in three markets. All isolates were clustered into 31, 33, and 15 different patterns with Simpson's index of diversity (SID) values of 0.972, 0.974, and 0.919, respectively. Sau-PCR assay was simpler, more rapid, and had higher discriminatory power than PFGE assay. Fla-DGGE assay could detect and illustrate the number of contamination types of C. jejuni and C. coli without cultivation, which saved more time and cost than Sau-PCR and PFGE assays. Therefore, Sau-PCR and fla-DGGE assays are both rapid, economical, and easy to perform, which have the potential to be promising and accessible for primary laboratories in genotyping C. coli strains.

Detecting the transverse spin density of light via electromagnetically induced transparency.

For light that is transversely confined, its field vector spins in a plane not orthogonal to the propagation direction, leading to the presence of transverse spin, which plays a fundamental role in the field of chiral quantum optics. Here, we theoretically propose a scheme to detect the transverse spin density (TSD) of light by utilizing a multilevel atomic medium. The scheme is based on the electromagnetically induced transparency effect, which enables the TSD-dependent modulation of the susceptibility of the atomic medium by using a coupling field whose TSD is to be detected. The modulated susceptibility results in a spin-dependent absorption for a probe beam passing through the atomic medium. We show that there exists a corresponding relationship between the TSD distribution of the coupling field and the polarization distribution of the transmitted probe beam through a theoretical study of two typical cases, in which the coupling field is provided by a tightly focused field and a two-beam interference field, respectively. Based on this relationship, the key features of the TSD of the coupling field, such as the spatial distribution, the symmetry property, and the spin-momentum locking, can be inferred from the transmitted probe beam. Benefiting from the fast response of the atomic medium to the variation of the coupling field, the present scheme is capable of detecting the TSD in real time, offering new possibilities for developing transverse-spin-based techniques.

Experimental realization of efficient nondegenerate four-wave mixing in cesium atoms.

Nondegenerate four-wave mixing (FWM) in diamond-type atomic systems has important applications in a wide range of fields, including quantum entanglement generation, frequency conversion, and optical information processing. Although the efficient self-seeded nondegenerate FWM with amplified spontaneous emission (ASE) has been realized extensively, the seeded nondegenerate FWM without ASE is inefficient in reported experiments so far. Here we present the experimental realization of the seeded nondegenerate FWM in cesium atoms with a significantly improved efficiency. Specifically, with two pump lasers at 852 and 921 nm and a seed laser at 895 nm, a continuous-wave laser at 876 nm is efficiently generated via FWM in a cesium vapor cell with a power up to 1.2 mW, three orders of magnitude larger than what has been achieved in previous experiments. The improvement of the efficiency benefits from the exact satisfaction of the phase-matching condition realized by an elaborately designed setup. Our results may find applications in the generation of squeezing and entanglement of light via nondegenerate FWM.

Propagation of Gaussian vortex beams in electromagnetically induced transparency media.

Electromagnetically induced transparency (EIT) is an important phenomenon in quantum optics, and has a wide range of applications in the fields of quantum information processing and quantum precision metrology. Recently, with the rapid progress of the generation and detection of structured light, the EIT with structured light has attracted enormous interests and offers new and novel functionalities and applications. Here, we theoretically study the propagation and evolution of Gaussian vortex beams, a typical type of structured light, in an EIT medium with Λ-type three-level atoms. Based on the generalized Huygens-Fresnel principle, we derive the analytical expressions of fully and partially coherent Gaussian vortex beams propagating in the EIT medium, and study the evolution of the intensity and phase distributions of the beams and their dependencies on parameters such topological charge, coherence length, Rabi frequency, etc. It is shown that both the fully and partially coherent Gaussian vortex beams undergo focusing and diverging periodically during propagation. The phase singularity of the fully coherent beam keeps unchanged, while the phase singularity of the partially coherent beam experiences splitting and recombination periodically. In addition, new phase singularities with opposite topological charge are generated in the latter case. Our results not only advance the study of the interaction between structured light and coherent media, but also pave the avenue for manipulating structured light via EIT.

The effects of terrain factors on the drainage area threshold: comparison of principal component analysis and correlation analysis.

How and to which extent terrain factors affecting the drainage area threshold (DAT) are disputable. This paper uses principal component analysis (PCA) and correlation analysis to study the influence degree of terrain factors on DAT. Firstly, 22 watersheds, locating in the severe soil erosion region (SSER) of Loess Plateau of China, are picked out as the example areas. The purpose of the mean change point method (MCP) to detect the relationship between DAT and gully density (GD) is to get a reasonable DAT. Secondly, nine terrain factors are calculated, and their statistical values are compared and put in the matrix to clear the different effects on DAT. Finally, the effects of statistical eigenvalues of terrain factors on DAT are compared with PCA and the correlation analysis. According to the PCA, the nine terrain factors are summarized into three principal components, which are slope, height variation, and relief factor. By calculating the score weighted by each factor coefficient matrix and eigenvalue, the result states that slope (S), terrain curvatures (K), and surface roughness (SR) are the factors that have great influence on DAT. Meanwhile, the results of correlation analysis indicate that S, SR, and K have exerted a great influence on the DAT, and the significance level was above 0.05. Both the results of PCA and correlation analysis make clear that the slope is the most direct and influential factor affecting DAT, while other factors are more or less related to slope directly and indirectly. The result implies that the vertical variation of terrain has a strong correlation with the slope, and also has a great influence on DAT. This research not only would be of great significance to recognize the mechanism of gully development, but also able to provide a scientific reference for soil and water conservation in the Loess Plateau.

Over 12 Years Single Institutional Experience Performing Percutaneous Hepatic Perfusion for Unresectable Liver Metastases.

Patients with unresectable hepatic metastases, from uveal or ocular melanoma, are challenging to treat with an overall poor prognosis. Although over the past decade significant advances in systemic therapies have been made, metastatic disease to the liver, especially from uveal melanoma, continues to be a poor prognosis. Percutaneous hepatic perfusion (PHP) is a safe, viable treatment option for these patients. PHP utilizes high dose chemotherapy delivered directly to the liver while minimizing systemic exposure and can be repeated up to 6 times. Isolation of the hepatic vasculature with a double-balloon catheter allows for high concentration cytotoxic therapy to be administered with minimal systemic adverse effects. A detailed description of the multidisciplinary treatment protocol used at an institution with over 12 years of experience is discussed and recommendations are given. A dedicated team of a surgical or medical oncology, interventional radiology, anesthesiology and a perfusionist allows PHP to be repeatedly performed as a safe treatment strategy for unresectable hepatic metastases.

Experimental Observation of Momentum-Space Chiral Edge Currents in Room-Temperature Atoms.

Chiral edge currents play an important role in characterizing topological matter. In atoms, they have been observed at such a low temperature that the atomic motion can be measured. Here we report the first experimental observation of chiral edge currents in atoms at room temperature. Staggered magnetic fluxes are induced by the spatial phase difference between two standing-wave light fields, which couple atoms to form a momentum-space zigzag superradiance lattice. The chiral edge currents are measured by comparing the directional superradiant emissions of two timed Dicke states in the lattice. Our results pave the way for simulating topological physics in hot atoms.

Improvement of reliability in multi-interferometer-based counterfactual deterministic communication with dissipation compensation.

The direct counterfactual quantum communication (DCQC) is a surprising phenomenon that quantum information can be transmitted without using any carriers of physical particles. The nested interferometers are promising devices for realizing DCQC as long as the number of interferometers goes to be infinity. Considering the inevitable loss or dissipation in practical experimental interferometers, we analyze the dependence of reliability on the number of interferometers, and show that the reliability of direct communication is being rapidly degraded with the large number of interferometers. Furthermore, we simulate and test this counterfactual deterministic communication protocol with a finite number of interferometers, and demonstrate the improvement of the reliability using dissipation compensation in interferometers.

Evidence for the association between IgG-antimitochondrial antibody and biochemical response to ursodeoxycholic acid treatment in primary biliary cholangitis.

BACKGROUND AND AIM: Antimitochondrial antibody (AMA) is considered the serological hallmark of primary biliary cholangitis (PBC), while data regarding the profile of AMA during ursodeoxycholic acid (UDCA) treatment are scarce. Here, we assessed the influence of UDCA treatment on titers of AMA and factors relevant to its production. METHODS: Serum IgA-AMA, IgM-AMA, IgG-AMA, B cell-activating factor of the tumor necrosis factor family (BAFF), and the frequency of circulating plasmablasts were detected in PBC patients, including those who received UDCA therapy for 24 weeks, healthy controls, chronic hepatitis B patients, and autoimmune hepatitis patients. Consecutive liver sections from controls and PBC patients were stained by immunohistochemistry for detection of intrahepatic CD38+ , IgA+ , IgM+ , and IgG+ cells. RESULTS: Significant decrease in titers of IgG-AMA was found only confined to PBC patients with biochemical response to UDCA treatment (P = 0.005), and similar pattern was also observed at week 24 in quantifying circulating plasmablasts (P = 0.025) and serum BAFF (P = 0.013). Notably, positive correlation between serum BAFF levels and titers of IgG-AMA, and the frequency of circulating plasmablasts were observed in PBC patients (r = 0.464, P = 0.034 and r = 0.700, P < 0.001, respectively). Additionally, in situ staining revealed significant accumulation of CD38+ and IgG+ cells within the portal tracts of PBC liver. CONCLUSIONS: Decreased titers of serum IgG-AMA are associated with biochemical response to UDCA treatment, implicating the potentiality of this hallmark in therapeutic response evaluation and the beneficial effect of UDCA on humoral immunity in PBC patients.

Single-frequency tunable 447.3 nm laser by frequency doubling of tapered amplified diode laser at cesium D1 line.

A continuous single-frequency tunable blue laser at 447.3 nm is developed by external-cavity frequency doubling of a tapered amplifier-boosted continuous-wave diode laser at cesium (Cs) D1 line. A maximum blue power of 178 mW with 50.8% conversion efficiency is obtained. It can be continuously tuned over a range around 1.6 GHz as the diode laser frequency is scanned across the F=4→F'=3 transition of 133Cs D1 line. The generated tunable and stable blue laser source has potential applications in constructing quantum light-atom interfaces in quantum networks.

Positional cloning uncovers mutations in PLCE1 responsible for a nephrotic syndrome variant that may be reversible.

Nephrotic syndrome, a malfunction of the kidney glomerular filter, leads to proteinuria, edema and, in steroid-resistant nephrotic syndrome, end-stage kidney disease. Using positional cloning, we identified mutations in the phospholipase C epsilon gene (PLCE1) as causing early-onset nephrotic syndrome with end-stage kidney disease. Kidney histology of affected individuals showed diffuse mesangial sclerosis (DMS). Using immunofluorescence, we found PLCepsilon1 expression in developing and mature glomerular podocytes and showed that DMS represents an arrest of normal glomerular development. We identified IQ motif-containing GTPase-activating protein 1 as a new interaction partner of PLCepsilon1. Two siblings with a missense mutation in an exon encoding the PLCepsilon1 catalytic domain showed histology characteristic of focal segmental glomerulosclerosis. Notably, two other affected individuals responded to therapy, making this the first report of a molecular cause of nephrotic syndrome that may resolve after therapy. These findings, together with the zebrafish model of human nephrotic syndrome generated by plce1 knockdown, open new inroads into pathophysiology and treatment mechanisms of nephrotic syndrome.

Design, synthesis, and anti-tumor activity of novel betulinic acid derivatives.

Seventeen new derivatives of betulinic acid (BA) with potential anti-tumor activity have been synthesized. In order to improve the bioactivity of BA, we connected BA and nitric oxide donors together via different linkers. The results of the biological activity of these derivatives showed that four compounds exhibited obvious cytotoxicity against human hepatocellular carcinoma cells in vitro.

Correlation between NGS panel-based mutation results and clinical information in colorectal cancer patients.

Early mutation identification guides patients with colorectal cancer (CRC) toward targeted therapies. In the present study, 414 patients with CRC were enrolled, and amplicon-based targeted next-generation sequencing (NGS) was then performed to detect genomic alterations within the 73 cancer-related genes in the OncoAim panel. The overall mutation rate was 91.5 % (379/414). Gene mutations were detected in 38/73 genes tested. The most frequently mutated genes were TP53 (60.9 %), KRAS (46.6 %), APC (30.4 %), PIK3CA (15.9 %), FBXW7 (8.2 %), SMAD4 (6.8 %), BRAF (6.5 %), and NRAS (3.9 %). Compared with the wild type, TP53 mutations were associated with low microsatellite instability/microsatellite stability (MSI-L/MSS) (P = 0.007), tumor location (P = 0.043), and histological grade (P = 0.0009); KRAS mutations were associated with female gender (P = 0.026), distant metastasis (P = 0.023), TNM stage (P = 0.013), and histological grade (P = 0.004); APC mutations were associated with patients <64 years of age at diagnosis (P = 0.04); PIK3CA mutations were associated with tumor location (P = 4.97e-06) and female gender (P = 0.018); SMAD4 mutations were associated with tumor location (P = 0.033); BRAF mutations were associated with high MSI (MSI-H; P = 6.968e-07), tumor location (P = 1.58e-06), and histological grade (P = 0.04). Mutations in 164 individuals were found to be pathogenic or likely pathogenic. A total of 26 patients harbored MSI-H tumors and they all had at least one detected gene mutation. Mutated genes were enriched in signaling pathways associated with CRC. The present findings have important implications for improving the personalized treatment of patients with CRC in China.

Degradation of Steel Rebar Tensile Properties Affected by Longitudinal Non-Uniform Corrosion.

Rebar corrosion is the primary cause of the durability degradation of reinforced concrete (RC) structures, where non-uniform corrosion is the typical pattern in engineering. This study experimentally and numerically investigated the tensile degradation properties of non-uniform corroded rebars. Corrosion morphology was accurately determined by three-dimensional (3D) laser scanning techniques, studying the characteristics of longitudinal non-uniform corrosion. The results showed that the non-uniformity of corrosion increased with an increase in corrosion levels. From tensile tests, the differences in nominal stress-strain curves among rebars with similar average corrosion levels indicated that corrosion non-uniformity has appreciable effects on the tensile behavior of rebars. The residual load-bearing capacity of corroded rebars was dominated by the reduced critical cross-section, while residual ductility was associated with the cross-section loss throughout the entire length of rebars. The degradation relations of nominal yield and ultimate strength, ultimate strain, and elongation after fracture were better correlated to the maximum cross-section loss than to the average volume loss. Additionally, numerical calculation based on the cross-sectional areas of corroded rebars was conducted to evaluate the tensile behavior of non-uniform corroded rebars. Equivalent distribution models simulating the longitudinal non-uniform corrosion were proposed, on the basis of probability characteristics of cross-sectional areas, for practical application of the numerical method.

Movement of Lipid Droplets in the Arabidopsis Pollen Tube Is Dependent on the Actomyosin System.

The growth of pollen tubes, which depends on actin filaments, is pivotal for plant reproduction. Pharmacological experiments showed that while oryzalin and brefeldin A treatments had no significant effect on the lipid droplets (LDs) trafficking, while 2,3-butanedione monoxime (BDM), latrunculin B, SMIFH2, and cytochalasin D treatments slowed down LDs trafficking, in such a manner that only residual wobbling was observed, suggesting that trafficking of LDs in pollen tube is related to F-actin. While the trafficking of LDs in the wild-type pollen tubes and in myo11-2, myo11b1-1, myo11c1-1, and myo11c2-1 single mutants and myo11a1-1/myo11a2-1 double mutant were normal, their trafficking slowed down in a myosin-XI double knockout (myo11c1-1/myo11c2-1) mutant. These observations suggest that Myo11C1 and Myo11C2 motors are involved in LDs movement in pollen tubes, and they share functional redundancy. Hence, LDs movement in Arabidopsis pollen tubes relies on the actomyosin system.