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FORMOSAT-7/COSMIC-2 radio occultation (RO) measurements show promise for observing the deep troposphere and for providing critical information on the Earth's planetary boundary layer (PBL). However, refractivity retrieved in the low troposphere can have severe biases under certain thermodynamic conditions. This research examines the characteristics of the deep tropospheric biases and presents methods for estimating the region-dependent refractivity bias using statistical regression models. The results show that the biases have characteristics that vary over land and oceans. With substantial correlation between local spectral width (LSW) and bias, the LSW-based bias estimation model can explain the general pattern of the refractivity bias but with deficiencies in measuring the bias in the ducting regions and in certain areas over land. The estimation model involving the relationship with temperature and specific humidity (TQ) can capture the large biases associated with ducting. Finally, a minimum variance estimation that combines the LSW and TQ provides the most accurate estimation of the refractivity bias.

Abstract We consider the fidelity of the vector meson dominance (VMD) assumption as an instrument for relating the electromagnetic vector-meson production reaction $$e + p \rightarrow e^\prime + V + p$$ e + p → e ′ + V + p to the purely hadronic process $$V + p \rightarrow V+p$$ V + p → V + p . Analyses of the photon vacuum polarisation and the photon-quark vertex reveal that such a VMD Ansatz might be reasonable for light vector-mesons. However, when the vector-mesons are described by momentum-dependent bound-state amplitudes, VMD fails for heavy vector-mesons: it cannot be used reliably to estimate either a photon-to-vector-meson transition strength or the momentum dependence of those integrands that would arise in calculations of the different reaction amplitudes. Consequently, for processes involving heavy mesons, the veracity of both cross-section estimates and conclusions based on the VMD assumption should be reviewed, e.g., those relating to hidden-charm pentaquark production and the origin of the proton mass.

Trigger factor (TF) is a highly conserved multi-domain molecular chaperone that exerts its chaperone activity at the ribosomal tunnel exit from which newly synthesized nascent chains emerge. TF also displays promiscuous substrate binding for a large number of cytosolic proteins independent of ribosome binding. We asked how TF recognizes a variety of substrates while existing in a monomer–dimer equilibrium. Paramagnetic nuclear magnetic resonance (NMR) and electron spin resonance (ESR) spectroscopy were used to show that dimeric TF displays a high degree of structural polymorphism in solution. A series of peptides has been generated to quantify their TF binding affinities in relation with their sequence compositions. The results confirmed a previous predication that TF preferentially binds to peptide fragments that are rich in aromatic and positively charged amino acids. NMR paramagnetic relaxation enhancement analysis showed that TF utilizes multiple binding sites, located in the chaperone domain and part of the prolyl trans–cis isomerization domain, to interact with these peptides. Dimerization of TF effectively sequesters most of the substrate binding sites, which are expected to become accessible upon binding to the ribosome as a monomer. As TF lacks ATPase activity, which is commonly used to trigger conformational changes within molecular chaperones in action, the ribosome-binding-associated disassembly and conformational rearrangements may be the underlying regulatory mechanism of its chaperone activity.

In Holsteins, emerging evidence suggests that long non-coding RNAs (lncRNAs) are actively involved in the regulation of mammary gland development. However, the lncRNA expression pattern in the early growth stage of Holstein mammary gland remains little known. In this study, we comprehensively analyzed 11 mammary gland tissue RNA-Seq datasets derived from Holstein heifer calves (ca. 8 weeks old) retrieved from the Sequence Read Archive database. We identified a total of 588 lncRNAs in the intergenic region. By comparing the sequences with NONCODEv5 database, 241 novel lncRNAs were detected in the mammary gland. Prediction of cis-regulated target gene revealed that 364 out of 588 lncRNAs potentially targeted 417 protein-coding genes. Furthermore, Gene Ontology enrichment determined that potential target genes were mainly involved in the terms associated with energy metabolism and cell differentiation, such as cellular respiration, respiratory electron transport chain, electron transport chain, and regulation of cell differentiation, which were closely related to mammary gland development. This study provides potential candidate lncRNAs in regulating mammary gland development in the early growth stage of Holsteins, as well as a better general understanding of Holstein mammary gland development.

Arctium lappa and A. tomentosum are known medicinal plants in China. The complete chloroplast genomes from A. lappa and A. tomentosum were sequenced using Illumina sequencing technology. The total genome sizes of the complete chloroplast genomes of A. lappa and A. tomentosum were 152 767 bp and 152 688 bp, respectively, and contained a pair of inverted repeats of the same length (15,181 bp). The small single-copies were 18 584 bp and 18 582 bp, and the large single-copies were 83 821 bp and 83 744 bp, respectively. We identified and annotated 134 and 126 genes from A. lappa and A. tomentosum including, respectively, 90 and 89 protein-coding genes, 36 and 29 tRNAs, and eight rRNAs. A. lappa was found to have 10 tRNAs different from those in A. tomentosum, and A. tomentosum had three tRNAs different from those in A. lappa. There were only two types of simple sequence repeats of two species, mononucleotide and dinucleotide, and the sequences were A and T rich. In addition, the two ways of phylogenetic analysis show that the position of A. lappa and A. tomentosum is consistent within Asteraceae.

Phosphoglycerate mutase (PGAM2) catalyzes the conversion of 3-phosphoglycerate into 2-phosphoglycerate and releases energy during glycolysis in muscle tissues. PGAM2 has been considered as a candidate gene to influence growth, development, and carcass traits in livestock. The aim of this study was to investigate the association between polymorphisms of PGAM2 and growth traits in rabbits. Three single nucleotide polymorphisms (SNPs) were identified by direct sequencing in 20 random individuals from three breeds, including c.-10C>T, c.195C>T, and c.414+17C>T. The c.195C>T was genotyped by PCR-RFLP in a total of 222 rabbits of three breeds (Tianfu black, 53 animals; Ira, 91 animals; Champagne, 78 animals). The average allele frequency among the breeds was 0.52 for allele T and 0.48 for C. The heterozygosity and effective number of alleles were 0.4992 and 1.996, respectively. The association results revealed the CT genotype of c.195C>T was associated significantly (P < 0.05) with greater body weight at 84 days of age (BW84) and with average daily weight gain (ADG). However, association of the genotypes with other production traits was not observed. The results of this study suggested PGAM2 is one of the candidate genes affecting BW84 and ADG in the rabbit.

This paper mainly studies the influence of process parameters on the forming quality during the spinning process of 6061 aluminum alloy wheel forging blanks. The four parameters of spinning temperature, spindle speed, wheel feed and wall thickness reduction rate are selected for research, and the quality of the surface of the hub and the influence on the size of the hub are judged. Simufact software is used to simulate the influence of various process parameters on the forming quality of the hub. The results provide a certain reference for the reasonable selection of process parameters during the spinning forming process of 6061 aluminum alloy hub.

The influence of electron cyclotron wave (ECW) injection with different deposition positions and injection powers on the evolution of peeling–ballooning (P–B) modes is studied with the BOUT++ code, in which the energy deposition and current drive of the ECW are calculated using a ray tracing code. It is shown that the changes in the profiles of plasma pressure, current density, and resistivity induced by ECW injection can significantly influence the linear property and the nonlinear evolution of P–B modes. For the linear simulation, the ECW deposited at the top of the pedestal makes the high toroidal mode number (n) P–B modes more unstable; however, it stabilizes the medium-n to high-n P–B modes when the ECW is deposited at the middle of the pedestal, and the ECW deposited at the bottom of the pedestal decreases the growth rate of P–B modes with medium-n. Further investigation shows that the injected ECW influences the characteristic of linear P–B modes by changing the diamagnetic effect, magnetic shear, pressure gradient, current density, resistivity, and so on. It is known from the nonlinear simulation that the energy loss caused by the edge localized mode (ELM) with ECW injection deposited at the top of the pedestal is nearly the same as that in the case without ECW injection, while the ECW deposited at the middle and bottom of the pedestal is helpful to decrease ELM energy loss. According to the analyses of the time evolution of the P–B mode toroidal spectrum, the physical mechanism of the decrease in ELM energy loss in the simulation is that ECW injection suppresses the most unstable toroidal harmonic of the P–B mode. On the other hand, the influence of ECW injection on P–B modes becomes more obvious when the power of the injected ECW increases. Moreover, the influence of current driven by the ECW on P–B modes is studied separately in this paper, which plays a different role from the bootstrap current.

The temperature effect on the mechanical behavior of the HfNbTaTiZr high entropy alloy (HEA) was investigated at 77–673 K. The decrease of the yield strength with increasing the temperature was mechanistically analyzed by considering contributions from various strengthening mechanisms. An anomalous dependence of strain hardening on temperature was observed and was justified to be caused by dynamic strain aging (DSA) as an extra strengthening mechanism at elevated temperatures. A model was constructed to split the overall strain hardening into forest hardening and DSA hardening, both of which were theoretically quantified at all temperatures considered.

[This corrects the article DOI: 10.1371/journal.ppat.1009404.].

Broadly neutralizing antibodies (bNAbs) directed to HIV-1 have shown promise at suppressing viremia in animal models. However, the use of bNAbs for the central nervous system (CNS) infection is confounded by poor penetration of the blood brain barrier (BBB). Typically, antibody concentrations in the CNS are extremely low; with levels in cerebrospinal fluid (CSF) only 0.1% of blood concentrations. Using a novel nanotechnology platform, which we term nanocapsules, we show effective transportation of the human bNAb PGT121 across the BBB in infant rhesus macaques upon systemic administration up to 1.6% of plasma concentration. We demonstrate that a single dose of PGT121 encased in nanocapsules when delivered at 48h post-infection delays early acute infection with SHIVSF162P3 in infants, with one of four animals demonstrating viral clearance. Importantly, the nanocapsule delivery of PGT121 improves suppression of SHIV infection in the CNS relative to controls.

Due to the durability and persistence of reservoirs of HIV-1-infected cells, combination antiretroviral therapy (ART) is insufficient in eradicating infection. Achieving HIV-1 cure or sustained remission without ART treatment will require the enhanced and persistent effective antiviral immune responses. Chimeric Antigen Receptor (CAR) T-cells have emerged as a powerful immunotherapy and show promise in treating HIV-1 infection. Persistence, trafficking, and maintenance of function remain to be a challenge in many of these approaches, which are based on peripheral T cell modification. To overcome many of these issues, we have previously demonstrated successful long-term engraftment and production of anti-HIV CAR T cells in modified hematopoietic stem cells (HSCs) in vivo. Here we report the development and in vivo testing of second generation CD4-based CARs (CD4CAR) against HIV-1 infection using a HSCs-based approach. We found that a modified, truncated CD4-based CAR (D1D2CAR) allows better CAR-T cell differentiation from gene modified HSCs, and maintains similar CTL activity as compared to the full length CD4-based CAR. In addition, D1D2CAR does not mediate HIV infection or stimulation mediated by IL-16, suggesting lower risk of off-target effects. Interestingly, stimulatory domains of 4-1BB but not CD28 allowed successful hematopoietic differentiation and improved anti-viral function of CAR T cells from CAR modified HSCs. Addition of 4-1BB to CD4 based CARs led to faster suppression of viremia during early untreated HIV-1 infection. D1D2CAR 4-1BB mice had faster viral suppression in combination with ART and better persistence of CAR T cells during ART. In summary, our data indicate that the D1D2CAR-41BB is a superior CAR, showing better HSC differentiation, viral suppression and persistence, and less deleterious functions compared to the original CD4CAR, and should continue to be pursued as a candidate for clinical study.

Tumor metastasis into the central nervous system (CNS) and lymph nodes (LNs) is a major obstacle for effective therapies. Therapeutic monoclonal antibodies (mAb) have revolutionized tumor treatment; however, their efficacy for treating metastatic tumors-particularly, CNS and LN metastases-is poor due to inefficient penetration into the CNS and LNs following intravenous injection. We recently reported an effective delivery of mAb to the CNS by encapsulating the anti-CD20 mAb rituximab (RTX) within a thin shell of polymer that contains the analogs of choline and acetylcholine receptors. This encapsulated RTX, denoted as n-RTX, eliminated lymphoma cells systemically in a xenografted humanized mouse model using an immunodeficient mouse as a recipient of human hematopoietic stem/progenitor cells and fetal thymus more effectively than native RTX; importantly, n-RTX showed notable anti-tumor effect on CNS metastases which is unable to show by native RTX. As an important step toward future clinical translation of this technology, we further analyzed the properties of n-RTX in immunocompetent animals, rats, and non-human primates (NHPs). Our results show that a single intravenous injection of n-RTX resulted in 10-fold greater levels in the CNS and 2-3-fold greater levels in the LNs of RTX, respectively, than the injection of native RTX in both rats and NHPs. In addition, we demonstrate the enhanced delivery and efficient B-cell depletion in lymphoid organs of NHPs with n-RTX. Moreover, detailed hematological analysis and liver enzyme activity tests indicate n-RTX treatment is safe in NHPs. As this nanocapsule platform can be universally applied to other therapeutic mAbs, it holds great promise for extending mAb therapy to poorly accessible body compartments.

Based on the magnetic field configuration of the Chinese First Quasi-axisymmetric Stellarator (CFQS) device, three types of orbits such as the passing orbit, blocked trapped orbit, and localized trapped orbit are simulated using the Boris algorithm. Also, the orbital topology, orbit transition, and loss characteristics of these particles under different initial conditions are studied in this paper. It is found that there exists a transition from blocked trapped orbits to localized trapped orbits due to small continuous helical ripples. This phenomenon is analyzed as follows: we define the angle between the particle drift velocity (v→D) and the radial direction (ρ^) as β. If the blocked-localized transition appears in the region where β>90○, the localized particles will return to the blocked particles and be constrained. However, if the blocked-localized transition happens in the region where β

Interfacial properties between metal back contacts and solar cell absorbers play important roles in determining efficiencies, but studies of such properties in CZTS and CZTSe based solar cells are quite lacking from theoretical aspects. To fill such a blank and explore insights for improving energy conversion efficiencies, we have studied interfacial properties in CZTS and CZTSe solar cells. The natural band offsets between CZTX and the spontaneously formed MoX2 layer (X = S, Se) are obtained using our recently developed intermediate-phase method. We find that the band alignment between CZTS and MoS2 is actually harmful while the band alignment between CZTSe and MoSe2 is beneficial for carrier extractions. We further propose to engineer the back contact interface to improve CZTS solar cell efficiency by depositing a thin layer of Se on the Mo back contact prior to the CZTS deposition, thus avoiding the formation of the undesirable MoS2 layer.

A novel approach for positron injection and acceleration in the laser driven plasma wakefield is proposed. One ring-shaped beam and one coaxially propagating Gaussian beam drive wakefields in a preformed plasma volume filled with both electrons and positrons. The laser’s ponderomotive force as well as the charge separation force in the front bucket of the first bubble are utilized to provide the transverse momenta of injected positrons and those positrons can be trapped by the focusing field and then accelerated by the wakefield. Theoretical analysis of the process is presented and verified by particle-in-cell simulations. The simulations show that relatively high-charge, quasimonoenergetic positron beams can be obtained.

In a recent clone-tracking experiment, millions of uniquely tagged hematopoietic stem cells (HSCs) and progenitor cells were autologously transplanted into rhesus macaques and peripheral blood containing thousands of tags were sampled and sequenced over 14 years to quantify the abundance of hundreds to thousands of tags or "clones." Two major puzzles of the data have been observed: consistent differences and massive temporal fluctuations of clone populations. The large sample-to-sample variability can lead clones to occasionally go "extinct" but "resurrect" themselves in subsequent samples. Although heterogeneity in HSC differentiation rates, potentially due to tagging, and random sampling of the animals' blood and cellular demographic stochasticity might be invoked to explain these features, we show that random sampling cannot explain the magnitude of the temporal fluctuations. Moreover, we show through simpler neutral mechanistic and statistical models of hematopoiesis of tagged cells that a broad distribution in clone sizes can arise from stochastic HSC self-renewal instead of tag-induced heterogeneity. The very large clone population fluctuations that often lead to extinctions and resurrections can be naturally explained by a generation-limited proliferation constraint on the progenitor cells. This constraint leads to bursty cell population dynamics underlying the large temporal fluctuations. We analyzed experimental clone abundance data using a new statistic that counts clonal disappearances and provided least-squares estimates of two key model parameters in our model, the total HSC differentiation rate and the maximum number of progenitor-cell divisions.

[This corrects the article DOI: 10.1371/journal.ppat.1006753.].

Chimeric Antigen Receptor (CAR) T-cells have emerged as a powerful immunotherapy for various forms of cancer and show promise in treating HIV-1 infection. However, significant limitations are persistence and whether peripheral T cell-based products can respond to malignant or infected cells that may reappear months or years after treatment remains unclear. Hematopoietic Stem/Progenitor Cells (HSPCs) are capable of long-term engraftment and have the potential to overcome these limitations. Here, we report the use of a protective CD4 chimeric antigen receptor (C46CD4CAR) to redirect HSPC-derived T-cells against simian/human immunodeficiency virus (SHIV) infection in pigtail macaques. CAR-containing cells persisted for more than 2 years without any measurable toxicity and were capable of multilineage engraftment. Combination antiretroviral therapy (cART) treatment followed by cART withdrawal resulted in lower viral rebound in CAR animals relative to controls, and demonstrated an immune memory-like response. We found CAR-expressing cells in multiple lymphoid tissues, decreased tissue-associated SHIV RNA levels, and substantially higher CD4/CD8 ratios in the gut as compared to controls. These results show that HSPC-derived CAR T-cells are capable of long-term engraftment and immune surveillance. This study demonstrates for the first time the safety and feasibility of HSPC-based CAR therapy in a large animal preclinical model.

Cellular retinol-binding protein II (CRBP II) belongs to the family of cellular retinol-binding proteins and plays a major role in absorption, transport, and metabolism of vitamin A. In addition, because vitamin A is correlated with reproductive performance, we measured CRBP II mRNA abundance in erlang mountainous chickens by real-time PCR using the relative quantification method. The expression of CRBP II showed a tissue-specific pattern and egg production rate-dependent changes. The expression was very high (p

Native chickens hold a significant share of the market in China. In response to the huge demand from the market, the productivity of Chinese native chickens needs to be improved. Cross breeding is an effective method to increase productivity, although it might affect meat quality. In this study, two pure lines (SD02 and SD03) of Erlang mountainous chickens were hybridized with a yellow feather and faster growing line (SD01). The effect of hybridization on carcass and meat quality (physiochemical and textural traits) was measured in the F1 population at d 91 of age. The hybrids exhibited higher body weight and dressed weight, and amount of semi-eviscerated, eviscerated, breast muscle and abdominal fat (p

Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This "shock" approach is then followed by "kill" of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells.

Cellular behaviour is controlled by numerous processes, including intracellular signalling pathways that are triggered by the binding of ligands with cell surface receptors. Multivalent ligands have multiple copies of a recognition element that binds to receptors and influences downstream signals. Nanoparticle-ligand complexes may form multivalent structures to crosslink receptors with high avidity and specificity. After conjugation onto gold nanoparticles, galectin-1 (Au-Gal1) bound with higher affinity to Jurkat cells to promote CD45 clustering and inhibition of its phosphatase activity, resulting in enhancement of apoptosis via caspase-dependent pathways. Au-Gal1 injected intra-articularly into rats with collagen-induced arthritis (CIA) promoted apoptosis of CD4+ T cells and reduced pro-inflammatory cytokine levels in the ankle joints as well as ameliorated clinical symptoms of arthritis. These observed therapeutic effects indicate that the multivalent structure of nanoparticle-ligands can regulate the distribution of cell surface receptors and subsequent intracellular signalling, and this may provide new insights into nanoparticle applications.

We described earlier a dual-combination anti-HIV type 1 (HIV-1) lentiviral vector (LVsh5/C46) that downregulates CCR5 expression of transduced cells via RNAi and inhibits HIV-1 fusion via cell surface expression of cell membrane-anchored C46 antiviral peptide. This combinatorial approach has two points of inhibition for R5-tropic HIV-1 and is also active against X4-tropic HIV-1. Here, we utilize the humanized bone marrow, liver, thymus (BLT) mouse model to characterize the in vivo efficacy of LVsh5/C46 (Cal-1) vector to engineer cellular resistance to HIV-1 pathogenesis. Human CD34+ hematopoietic stem/progenitor cells (HSPC) either nonmodified or transduced with LVsh5/C46 vector were transplanted to generate control and treatment groups, respectively. Control and experimental groups displayed similar engraftment and multilineage hematopoietic differentiation that included robust CD4+ T-cell development. Splenocytes isolated from the treatment group were resistant to both R5- and X4-tropic HIV-1 during ex vivo challenge experiments. Treatment group animals challenged with R5-tropic HIV-1 displayed significant protection of CD4+ T-cells and reduced viral load within peripheral blood and lymphoid tissues up to 14 weeks postinfection. Gene-marking and transgene expression were confirmed stable at 26 weeks post-transplantation. These data strongly support the use of LVsh5/C46 lentiviral vector in gene and cell therapeutic applications for inhibition of HIV-1 infection.

Small RNAs, including siRNAs, gRNAs and miRNAs, modulate gene expression and serve as potential therapies for human diseases. Delivery to target cells remains the fundamental limitation for use of these RNAs in humans. To address this challenge, we have developed a nanocapsule delivery technology that encapsulates small DNA molecules encoding RNAs into a small (30 nm) polymer nanocapsule. For proof of concept, we transduced DNA expression cassettes for three small RNAs. In one application, the DNA cassette encodes an shRNA transcriptional unit that downregulates CCR5 and protects from HIV-1 infection. The DNA cassette nanocapsules were further engineered for timed release of the DNA cargo for prolonged knockdown of CCR5. Secondly, the nanocapsules provide an efficient means for delivery of gRNAs in the CRISPR/Cas9 system to mutate integrated HIV-1. Finally, delivery of microRNA-125b to mobilized human CD34+ cells enhances survival and expansion of the CD34+ cells in culture.

Transplantation of hematopoietic stem/progenitor cells (HSPC) modified with a lentiviral vector bearing a potent nontoxic short hairpin RNA (sh1005) directed to the HIV coreceptor CCR5 is capable of continuously producing CCR5 downregulated CD4+ T lymphocytes. Here, we characterized HIV-1 resistance of the sh1005-modified CD4+ T lymphocytes in vivo in humanized bone marrow/liver/thymus (hu BLT) mice. The sh1005-modified CD4+ T lymphocytes were positively selected in CCR5-tropic HIV-1–challenged mice. The sh1005-modified memory CD4+ T lymphocytes (the primary target of CCR5-tropic HIV-1) expressing sh1005 were maintained in lymphoid tissues in CCR5-tropic HIV-1–challenged mice. Frequencies of HIV-1 p24 expressing cells were significantly reduced in the sh1005-modified splenocytes by ex vivo cell stimulation confirming that CCR5 downregulated sh1005 modified cells are protected from viral infection. These results demonstrate that stable CCR5 downregulation through genetic modification of human HSPC by lentivirally delivered sh1005 is highly effective in providing HIV-1 resistance. Our results provide in vivo evidence in a relevant small animal model that sh1005 is a potent early-step anti-HIV reagent that has potential as a novel anti-HIV-1 HSPC gene therapeutic reagent for human applications.

The use of siRNAs to knock down gene expression can potentially be an approach to treat various diseases. To avoid siRNA toxicity the less transcriptionally active H1 pol III promoter, rather than the U6 promoter, was proposed for siRNA expression. To identify highly efficacious siRNA sequences, extensive screening is required, since current computer programs may not render ideal results. Here, we used CCR5 gene silencing as a model to investigate a rapid and efficient screening approach. We constructed a chimeric luciferase-CCR5 gene for high-throughput screening of siRNA libraries. After screening approximately 900 shRNA clones, 12 siRNA sequences were identified. Sequence analysis demonstrated that most (11 of the 12 sequences) of these siRNAs did not match those identified by available siRNA prediction algorithms. Significant inhibition of CCR5 in a T-lymphocyte cell line and primary T cells by these identified siRNAs was confirmed using the siRNA lentiviral vectors to infect these cells. The inhibition of CCR5 expression significantly protected cells from R5 HIV-1JRCSF infection. These results indicated that the high-throughput screening method allows efficient identification of siRNA sequences to inhibit the target genes at low levels of expression.

A 52-year-old man visited our hospital complaining of anorexia and fatigue two months after receiving orthotopic liver transplantation for hepatocellular carcinoma. A laboratory investigation demonstrated a clinical picture of obstructive jaundice. T-tube cholangiography showed biliary stricture over the anastomotic site. Percutaneous transluminal balloon dilatation and stenting was attempted but failed. Magnetic resonance cholangiography showed possible tumor recurrence over the site of the anastomotic biliary stricture. A biopsy sample was obtained via ultrasound-guided aspiration and histopathological study revealed inflammatory and fibrotic changes. With high suspicion of recurrence of the hepatocellular carcinoma, surgical exploration was performed and an intraoperative frozen section proved the recurrence. We thus diagnosed this case as a recurrence of hepatocellular carcinoma after liver transplantation. To our knowledge, there have been no previous reports of early tumor recurrence after liver transplantation being the cause of an anastomotic biliary stricture.Un varón de 52 años visitó nuestro hospital quejándose de anorexia y fatiga a los dos meses de haber recibido un trasplante hepático ortotópico a causa de un carcinoma hepatocelular. La analítica mostró un cuadro clínico de ictericia obstructiva. La colangiografía con tubo en T mostró una estenosis biliar sobre la anastomosis. Se intentó una dilatación transluminal percutánea con globo y colocación de endoprótesis, que fracasó. La colangiografía por resonancia magnética mostró una posible recurrencia tumoral sobre el lugar de la estenosis biliar anastomótica. Se extrajo una muestra de biopsia mediante aspiración bajo guía ecográfica y el estudio histopatológico mostró alteraciones inflamatorias y fibróticas. Al sospecharse la recurrencia del carcinoma hepatocelular, se realizó una exploración quirúrgica; un corte intraoperatorio congelado demostró dicha recurrencia. Así, diagnosticamos este caso como la recurrencia de un carcinoma hepatocelular después de un trasplante de hígado. Que sepamos, no se ha publicado anteriormente ninguna recurrencia tumoral precoz posterior a un trasplante hepático que fuera causa de estenosis biliar anastomótica.

Down-regulation of the HIV-1 coreceptor CCR5 holds significant potential for long-term protection against HIV-1 in patients. Using the humanized bone marrow/liver/thymus (hu-BLT) mouse model which allows investigation of human hematopoietic stem/progenitor cell (HSPC) transplant and immune system reconstitution as well as HIV-1 infection, we previously demonstrated stable inhibition of CCR5 expression in systemic lymphoid tissues via transplantation of HSPCs genetically modified by lentiviral vector transduction to express short hairpin RNA (shRNA). However, CCR5 down-regulation will not be effective against existing CXCR4-tropic HIV-1 and emergence of resistant viral strains. As such, combination approaches targeting additional steps in the virus lifecycle are required. We screened a panel of previously published shRNAs targeting highly conserved regions and identified a potent shRNA targeting the R-region of the HIV-1 long terminal repeat (LTR). Here, we report that human CD4(+) T-cells derived from transplanted HSPC engineered to co-express shRNAs targeting CCR5 and HIV-1 LTR are resistant to CCR5- and CXCR4- tropic HIV-1-mediated depletion in vivo. Transduction with the combination vector suppressed CXCR4- and CCR5- tropic viral replication in cell lines and peripheral blood mononuclear cells in vitro. No obvious cytotoxicity or interferon response was observed. Transplantation of combination vector-transduced HSPC into hu-BLT mice resulted in efficient engraftment and subsequent stable gene marking and CCR5 down-regulation in human CD4(+) T-cells within peripheral blood and systemic lymphoid tissues, including gut-associated lymphoid tissue, a major site of robust viral replication, for over twelve weeks. CXCR4- and CCR5- tropic HIV-1 infection was effectively inhibited in hu-BLT mouse spleen-derived human CD4(+) T-cells ex vivo. Furthermore, levels of gene-marked CD4(+) T-cells in peripheral blood increased despite systemic infection with either CXCR4- or CCR5- tropic HIV-1 in vivo. These results demonstrate that transplantation of HSPCs engineered with our combination shRNA vector may be a potential therapy against HIV disease.

Human induced pluripotent stem cells (hiPSCs) provide new possibilities for regenerative therapies. In order for this potential to be achieved, it is critical to efficiently monitor the differentiation of these hiPSCs into specific lineages. Here, we describe a lentiviral reporter vector sensitive to specific microRNAs (miRNA) to show that a single vector bearing multiple miRNA target sequences conjugated to different reporters can be used to monitor hiPSC formation and subsequent differentiation from human fetal fibroblasts (HFFs). The reporter vector encodes EGFP conjugated to the targets of human embryonic stem cell (hESC) specific miRNAs (miR-302a and miR-302d) and mCherry conjugated to the targets of differentiated cells specific miRNAs (miR-142-3p, miR-155, and miR-223). The vector was used to track reprogramming of HFF to iPSC. HFFs co-transduced with this reporter vector and vectors encoding 4 reprogramming factors (OCT4, SOX2, KLF4 and cMYC) were mostly positive for EGFP (67%) at an early stage of hiPSC formation. EGFP expression gradually disappeared and mCherry expression increased indicating less miRNAs specific to differentiated cells and expression of miRNAs specific to hESCs. Upon differentiation of the hiPSC into embryoid bodies, a large fraction of these hiPSCs regained EGFP expression and some of those cells became single positive for EGFP. Further differentiation into neural lineages showed distinct structures demarcated by either EGFP or mCherry expression. These findings demonstrate that a miRNA dependent reporter vector can be a useful tool to monitor living cells during reprogramming of hiPSC and subsequent differentiation to lineage specific cells.

HIV-1 is restricted for infection of primary quiescent T-cells. After viral entry, reverse transcription is initiated but is not completed. Various hypotheses have been proposed for this cellular restriction including insufficient nucleotide pools and cellular factors, but none have been confirmed as the primary mechanism for restriction. A recent study by Chiu et al. implicates APOBEC3G, an anti-retroviral cytidine deaminase, as the cellular restriction factor. Here, we attempted to confirm these findings using the same strategy as reported by Chiu et al. of siRNA targeting knock-down of APOBEC3G expression. In contrast to the published study, our results do not support a role for APOBEC3G in restriction of HIV-1 in quiescent CD4+ T-cells. In our study, we tested the same siRNA as reported by Chiu et al. as well as two additional siRNAs targeting APOBEC3G, one of which showed 2-fold greater knock-down of APOBEC3G mRNA. However, none of the three siRNAs tested had a discernable effect on enhancing infection by HIV-1 in quiescent CD4+ T-cells. Therefore, we conclude that the primary mechanism of HIV-1 restriction in quiescent CD4+ T-cells remains to be elucidated.

The emergence of global value chains (GVC) has broadened the configurations of business activities across the entire value chains, yet little attention has been paid to the suppliers compared to lead firms. Rising suppliers from emerging markets successfully take orders and follow global buyers' steps to enter the internationalization as emerging market (EM) firms. This conceptual study aims to explore how EM suppliers leverage GVC to demonstrate reverse innovation by linking GVC research with enriched insights from a literature review of the Uppsala model. We argue that the suppliers have distinct roles as another possible route to drive GVC development. [ABSTRACT FROM AUTHOR]

Background: How a potentially diverse population of hematopoietic stem cells (HSCs) differentiates and proliferates to supply more than 1011 mature blood cells every day in humans remains a key biological question. We investigated this process by quantitatively analyzing the clonal structure of peripheral blood that is generated by a population of transplanted lentivirus-marked HSCs in myeloablated rhesus macaques. Each transplanted HSC generates a clonal lineage of cells in the peripheral blood that is then detected and quantified through deep sequencing of the viral vector integration sites (VIS) common within each lineage. This approach allowed us to observe, over a period of 4-12 years, hundreds of distinct clonal lineages. Results: While the distinct clone sizes varied by three orders of magnitude, we found that collectively, they form a steady-state clone size-distribution with a distinctive shape. Steady-state solutions of our model show that the predicted clone size-distribution is sensitive to only two combinations of parameters. By fitting the measured clone size-distributions to our mechanistic model, we estimate both the effective HSC differentiation rate and the number of active HSCs. Conclusions: Our concise mathematical model shows how slow HSC differentiation followed by fast progenitor growth can be responsible for the observed broad clone size-distribution. Although all cells are assumed to be statistically identical, analogous to a neutral theory for the different clone lineages, our mathematical approach captures the intrinsic variability in the times to HSC differentiation after transplantation. [ABSTRACT FROM AUTHOR]

Dectin-1 plays a critical role in the pathogenesis of intestinal inflammation by recognizing the pathogenic agents and mediating cytokine responses. The objective of this study was to establish the association between dectin-1 polymorphisms and susceptibility to nonspecific digestive disorders (NSDD) and cytokine expression in rabbits. A total of 7 coding SNP were detected in dectin-1 gene. The genetic association between SNP (ss707197675A > G) and susceptibility to NSDD was evaluated using a case-control study (178 cases and 174 controls). The results revealed that the A allele was associated with an increased risk of developing NSDD in rabbits. The AA genotype significantly increased the genetic susceptibility to NSDD with odds ratio of 4.76 (95% confidence interval, 1.92-12.50, P = 0.0002) compared with GG and GA genotypes. We also experimentally induced NSDD in another independent growing rabbit population by feeding a low-fiber diet and subsequently investigated the cytokine mRN A expression. Among the 4 studied cytokines, the expression of interferon-y, 1L-17F, and IL-22 were increased 2.8 to 6.0- fold in AA genotype compared with GG genotype (P < 0.01). The greater IL-17F and IL-22 mRNA expressions indicated a positive correlation with severe intestinal inflammation (P < 0.05). The decreased expression of IL-10 was associated with severe intestinal inflammation (P = 0.006), but IL-10 expression was not influenced by dectin-1 genotype. In conclusion, polymorphism ss707197675 of dectin-1 is related with susceptibility to NSDD and increased expression of proinflammatory cytokines, and dectin-1 could be an important candidate gene associated with NSDD in rabbits. [ABSTRACT FROM AUTHOR]

Transforming growth factor β (TGF-β) is a multifunctional cytokine with fi brogenic properties. Previous studies demonstrated that Phosphatidylinositol 3-Kinase (PI3K)/Akt/ mammalian target of Ramycin (mTOR), a non-Smad TGF-β pathway, plays an important role in the fi brotic pathogenesis of diff erent organs such as the lung, kidney, skin and liver. However, the role of PI3k- Akt pathway in fi brosis in injured skeletal muscle is still unclear. In this study, we determined the fi brotic role of PI3K-Akt pathway in injured skeletal muscle. We established a mouse model for acute muscle contusion. Western blotting analysis showed that TGF-β, phosphorylated Akt and phosphorylated mTOR were increased in muscles after acute contusion, which indicated that the PI3K-Akt- mTOR pathway was activated in skeletal muscle after acute contusion. The pathway was inhibited by a PI3K inhibitor, LY294002. Moreover, the expression of fi brosis markers vimentin, α SMA and collagen I and the area of scar decreased in injured skeletal muscle after PI3K pathway was blocked. The muscle function improved in terms of both fast-twitch and tetanic strength after PI3K/Akt pathway was inhibited in injured skeletal muscle. In conclusion, activation of PI3K-Akt-mTOR pathway might promote collagen production and scar formation in the acute contused skeletal muscle. Blocking of PI3K-AktmTOR pathway could improve the function of injured skeletal muscle. [ABSTRACT FROM AUTHOR]

Fishbone instability excited by energetic electrons during electron cyclotron resonant heating (ECRH) is identified on HL-2A.With high-power ECRH, periodic frequency jump phenomena are observed by soft x-ray arrays. Soft x-ray tomography shows that the poloidal and toroidal mode numbers are 1/1 and 2/2 with the frequency jump. There is an ECRH power threshold for the frequency jump phenomena, which is generally about 0.9MW. The frequencies of the two modes increase with the ECRH power. Experiments show that trapped particles are dominant in the low-density high-power ECRH plasma. The precessional frequency of the energetic trapped electrons is calculated with different discharge parameters. The results indicate that the energy of resonant electrons is in agreement with the hard x-ray measurement. [ABSTRACT FROM AUTHOR]

We propose a giant magnetoresistance (GMR) device, which can be experimentally realized by depositing two ferromagnetic (FM) strips and a Schottky metal (SM) stripe in parallel configuration on top of the GaAs heterostructure. The GMR effect ascribes a significant electron transmission difference between the parallel and antiparallel magnetization configurations of two FM stripes. Moreover, the MR ratio depends strongly on the magnetic strength of the magnetic barrier (MB) and the electric barrier (EB) height induced by an applied voltage to the SM stripe. Thus, this system can be used as a GMR device with tunable MR by an applied voltage to SM stripe or by magnetic strength of the MB. [ABSTRACT FROM AUTHOR]

Human induced pluripotent stem cells (hiPSCs) provide new possibilities for regenerative therapies. In order for this potential to be achieved, it is critical to efficiently monitor the differentiation of these hiPSCs into specific lineages. Here, we describe a lentiviral reporter vector sensitive to specific microRNAs (miRNA) to show that a single vector bearing multiple miRNA target sequences conjugated to different reporters can be used to monitor hiPSC formation and subsequent differentiation from human fetal fibroblasts (HFFs). The reporter vector encodes EGFP conjugated to the targets of human embryonic stem cell (hESC) specific miRNAs (miR-302a and miR-302d) and mCherry conjugated to the targets of differentiated cells specific miRNAs (miR-142-3p, miR-155, and miR-223). The vector was used to track reprogramming of HFF to iPSC. HFFs co-transduced with this reporter vector and vectors encoding 4 reprogramming factors (OCT4, SOX2, KLF4 and cMYC) were mostly positive for EGFP (67%) at an early stage of hiPSC formation. EGFP expression gradually disappeared and mCherry expression increased indicating less miRNAs specific to differentiated cells and expression of miRNAs specific to hESCs. Upon differentiation of the hiPSC into embryoid bodies, a large fraction of these hiPSCs regained EGFP expression and some of those cells became single positive for EGFP. Further differentiation into neural lineages showed distinct structures demarcated by either EGFP or mCherry expression. These findings demonstrate that a miRNA dependent reporter vector can be a useful tool to monitor living cells during reprogramming of hiPSC and subsequent differentiation to lineage specific cells. [ABSTRACT FROM AUTHOR]

A new class of ionic conducting organic/inorganic hybrid composite electrolyte with high conductivity, better electrochemical stability and mechanical behavior was prepared through the sol–gel processing between ethylene‐bridged polysilsesquioxane and poly(ethylene glycol) (PEG). The composite electrolyte with 0.05 LiClO4 per PEG repeat unit has the best conductivity up to 10−4 S/cm at room temperature with the transference number up to 0.48 and an electrochemical stability window as high as 5.5 V versus Li/Li+. Moreover, the effect of the PEG chain length on the properties of the composite electrolyte has also been studied. The interactions between ions and polymer have also been investigated for the composite electrolyte in the presence of LiClO4 by means of FTIR, DSC, and TGA. The results indicated the interaction of Li+ ions with the ether oxygen of the PEG, and the formation of transient crosslinking with LiClO4, resulting in an increase of the Tg of the composite electrolyte. The VTF‐type behavior of the ionic conductivity implied that the diffusion of the charge carriers was assisted by the segmental motions of the polymer chains. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2752–2758, 2007 [ABSTRACT FROM AUTHOR]

Inhibition of apoptosis plays an important role in the cellular immortalization and transformation induced by E6 and E7 oncoproteins of human papillomavirus (HPV). Here, we report that the transcription of the inhibitor of apoptosis gene, cellular inhibitor of apoptosis protein 2, (c-IAP2), is significantly upregulated in HPV16 E6/E7-immortalized human oral keratinocytes (HOK16E6E7). Overexpression of E6/E7 from the high-risk HPV16 or 18, but not from the low-risk HPV6, activated c-IAP2 promoter. E6 from HPV16 and 18 played a major role in the activation. In addition, the induction of c-IAP2 transcription required nuclear factor-κB activity. Overexpression of c-IAP2 in normal human oral keratinocyte conferred resistance to tumor necrosis factor-α (TNF-α)/cycloheximide (CHX)-induced apoptosis, suggesting the increased c-IAP2 expression in HOK16E6E7 may protect the cells from TNF-α-mediated cell death. Moreover, depletion of endogenous c-IAP2 using RNA interference in HOK16E6E7 induced apoptosis, indicating that c-IAP2 is necessary for HPV16 E6/E7-induced resistance to apoptosis and cell survival. Of note, high levels of c-IAP2 transcription were found in several HPV16- or HPV18-positive cancer cells, and depletion of c-IAP2 caused cell death in HPV18-positive HeLa cells. Thus, upregulation of c-IAP2 by E6 and E7 may confer resistance to apoptosis that is necessary for sustained growth of some HPV16- and HPV18-positive cancer cells.Oncogene (2005) 24, 5069–5078. doi:10.1038/sj.onc.1208691; published online 25 April 2005 [ABSTRACT FROM AUTHOR]

It is now believed that the scaling exponents of moments of velocity increments are anomalous, or that the departures from Kolmogorov's (1941) self-similar scaling increase nonlinearly with the increasing order of the moment. This appears to be true whether one considers velocity increments themselves or their absolute values. However, moments of order lower than 2 of the absolute values of velocity increments have not been investigated thoroughly for anomaly. Here, we discuss the importance of the scaling of non-integer moments of order between +2 and $-1$, and obtain them from direct numerical simulations at moderate Taylor microscale Reynolds numbers $R_\lambda\le$ 450, and experimental data at high Reynolds numbers $(R_\lambda \approx 10\,000)$. The relative difference between the measured exponents and Kolmogorov's prediction increases as the moment order decreases towards $-1$, thus showing that the anomaly is manifested in low-order moments as well. [ABSTRACT FROM AUTHOR]