Physical Mechanism of the Transverse Instability in Radiation Pressure Ion Acceleration

The transverse stability of the target is crucial for obtaining high quality ion beams using the laser radiation pressure acceleration (RPA) mechanism. In this Letter, a theoretical model and supporting two-dimensional (2D) particle-in-cell (PIC) simulations are presented to clarify the physical mechanism of the transverse instability observed in the RPA process. It is shown that the density ripples of the target foil are mainly induced by the coupling between the transverse oscillating electrons and the quasistatic ions, a mechanism similar to the oscillating two stream instability in the inertial confinement fusion research. The predictions of the mode structure and the growth rates from the theory agree well with the results obtained from the PIC simulations in various regimes, indicating the model contains the essence of the underlying physics of the transverse breakup of the target.

The antisense expression of

Although phosphoenolpyruvate carboxylases (PEPCs) are reported to be involved in fatty acid accumulation, nitrogen assimilation, and salt and drought stresses, knowledge regarding PEPC gene functions is still limited, particularly in peanuts (Arachis hypogaea L.). In this study, the antisense expression of the peanut PEPC isoform 1 (AhPEPC1) gene increased the lipid content by 5.7%–10.3%. This indicated that AhPEPC1 might be related to plant lipid accumulation. The transgenic plants underwent more root elongation than the wild-type under salinity stress. Additionally, the specific down regulation of the AhPEPC1 gene improved the salt tolerance in peanuts. This is the first report on the role of PEPC in lipid accumulation and salt tolerance in peanuts.

[Analysis of clinical characteristics and prognosis of non-severe aplastic anemia children with chromosomal abnormalities]

Objective: To analyze the clinical characteristics and prognosis of non-severe aplastic anemia (NSAA) with chromosomal abnormalities in children. Method: A retrospective analysis of 304 cases with NSAA with successful karyotyping from 2001 to 2014 in the Institute of Hematology & Blood Disease Hospital was carried out. The treatment response, condition of blood transfusion were analyzed using χ² test, the cumulative survival was estimated by the Kaplan-Meier method. Result: Out of 304 patients, 28 patients had chromosomal abnormalities with trisomy 8 (7 cases, 25.0%), abnormalities in chromosome 7 (5 cases, 17.9%), and other types (16 cases, 57.1%). There were no significant differences in the treatment response(40.9% (9/22)vs. 58.6%(119/203), χ²=2.539, P=0.111), the rate of getting rid of blood transfusion(54.5%(6/11) vs. 65.0%(39/60), χ²=6.455, P=0.086), five-year progression-free survival (49.2% vs.70.8%, χ²=0.849, P=0.357), and five-year cumulative survival (79.1% vs. 92.8%, χ²=0.330, P=0.556) between the patients with or without chromosomal abnormalities. There were significant differences in the rate of disease progression(41.7%(10/24) vs. 22.3%(48/215), χ²=4.394, P=0.045), the incidence of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML) (20.8%(5/24)vs. 0.9%(2/215), χ²=30.082, P=0.000)and the five-year cumulative incidence of MDS or AML(33.4% vs. 0.8%, χ²=17.798, P=0.000)between children with and without chromosomal abnormalities. Conclusion: The incidence of chromosomal abnormalities in children with NSAA is 9.2%. The clinical features and treatment response are similar, but children with chromosomal abnormalities have a poorer prognosis, and have higher risk of progressing to MDS or AML.

Preparation of Entangled States through Hilbert Space Engineering

We apply laser fields to trapped atomic ions to constrain the quantum dynamics from a simultaneously applied global microwave field to an initial product state and a target entangled state. This approach comes under what has become known in the literature as "quantum Zeno dynamics" and we use it to prepare entangled states of two and three ions. With two trapped ^{9}Be^{+} ions, we obtain Bell state fidelities up to 0.990_{-5}^{+2}; with three ions, a W-state fidelity of 0.910_{-7}^{+4} is obtained. Compared to other methods of producing entanglement in trapped ions, this procedure can be relatively insensitive to certain imperfections such as fluctuations in laser intensity.

High-Fidelity Universal Gate Set for ^{9}Be^{+} Ion Qubits

We report high-fidelity laser-beam-induced quantum logic gates on magnetic-field-insensitive qubits comprised of hyperfine states in ^{9}Be^{+} ions with a memory coherence time of more than 1 s. We demonstrate single-qubit gates with an error per gate of 3.8(1)×10^{-5}. By creating a Bell state with a deterministic two-qubit gate, we deduce a gate error of 8(4)×10^{-4}. We characterize the errors in our implementation and discuss methods to further reduce imperfections towards values that are compatible with fault-tolerant processing at realistic overhead.

Nanoscale Electron Bunching in Laser-Triggered Ionization Injection in Plasma Accelerators

Ionization injection is attractive as a controllable injection scheme for generating high quality electron beams using plasma-based wakefield acceleration. Because of the phase-dependent tunneling ionization rate and the trapping dynamics within a nonlinear wake, the discrete injection of electrons within the wake is nonlinearly mapped to a discrete final phase space structure of the beam at the location where the electrons are trapped. This phenomenon is theoretically analyzed and examined by three-dimensional particle-in-cell simulations which show that three-dimensional effects limit the wave number of the modulation to between >2k_{0} and about 5k_{0}, where k_{0} is the wave number of the injection laser. Such a nanoscale bunched beam can be diagnosed by and used to generate coherent transition radiation and may find use in generating high-power ultraviolet radiation upon passage through a resonant undulator.

Capturing relativistic wakefield structures in plasmas using ultrashort high-energy electrons as a probe

A new method capable of capturing coherent electric field structures propagating at nearly the speed of light in plasma with a time resolution as small as a few femtoseconds is proposed. This method uses a few femtoseconds long relativistic electron bunch to probe the wake produced in a plasma by an intense laser pulse or an ultra-short relativistic charged particle beam. As the probe bunch traverses the wake, its momentum is modulated by the electric field of the wake, leading to a density variation of the probe after free-space propagation. This variation of probe density produces a snapshot of the wake that can directly give many useful information of the wake structure and its evolution. Furthermore, this snapshot allows detailed mapping of the longitudinal and transverse components of the wakefield. We develop a theoretical model for field reconstruction and verify it using 3-dimensional particle-in-cell (PIC) simulations. This model can accurately reconstruct the wakefield structure in the linear regime, and it can also qualitatively map the major features of nonlinear wakes. The capturing of the injection in a nonlinear wake is demonstrated through 3D PIC simulations as an example of the application of this new method.

Meta-analysis of the IL-10 promoter polymorphisms and pediatric asthma susceptibility

The results of previous epidemiological studies exploring the relationship between interleukin-10 (IL-10) promoter polymorphisms and susceptibility to pediatric asthma are not consistent. Therefore, we have performed a systematic review and meta-analysis to provide a more convincing conclusion. Odds ratios (OR) with their 95% confidence intervals (CIs) were used to evaluate the strength of association between the IL-10 promoter polymorphisms and susceptibility to pediatric asthma. Publication bias was examined by Begg's funnel plots and the Egger test. A detailed literature search based on stringent parameters yielded sixteen relevant studies, comprising 2494 cases and 2160 controls. The overall population showed no significant association between the IL-10 -1082G/A polymorphism and pediatric asthma risk in any of the genetic models (dominant model: OR = 1.583, 95%CI = 0.614-4.076, P = 0.342; allelic model: OR = 1.214, 95%CI = 0.748-1.971, P = 0.433; additive model: OR = 2.240, 95%CI = 0.950-5.277, P = 0.065; recessive model: OR = 1.435, 95%CI = 0.659-3.128, P = 0.363). Subgroup analyses revealed a significant association between different ethnicity and atopic status subgroups. However, there was no evidence of a significant association between the other two polymorphisms (-819C/ T and -592C/A) and pediatric asthma in our study. No significant publication bias was observed in this meta-analysis. The results of this study indicate that the IL-10 -1082G/A polymorphism might be a risk factor for asthma in children. However, because of the small sample size included in the subgroup analyses, the results should be interpreted with caution.

Cardiac Specific Overexpression of hHole Attenuates Isoproterenol-Induced Hypertrophic Remodeling through Inhibition of Extracellular Signal-Regulated Kinases (ERKs) Signalling

The human Hole gene (hHole) encodes a six-transmembrane protein with 319- amino acids. Our previous study showed that hHole was strongly expressed in adult heart and may act as a suppressor of extracellular signal-regulated kinases (ERKs), overactivation of which contributed to pathological cardiac hypertrophy. In this study, it was observed that Hole expression was up-regulated in murine hypertrophic hearts. In a cardiac specific transgenic mouse model, it was observed that overexpression of hHole specifically in heart attenuated cardiac hypertrophy and fibrosis induced by isoproterenol (ISO), with blunted transcriptions of ERK1/2, total ERK1/2 proteins and phosphorylated ERK1/2 (p-ERK1/2) levels. Furthermore, overexpression of hHole in mice by hydrodynamic tail-vein injection with hHole plamids also inhibited cardiac hypertrophy induced by ISO. Our work identified hHole as a novel repressor of cardiac hypertrophy, and provided new insights into the possible target for the prevention or treatment of cardiac diseases.

Endosome Escape Strategies for Improving the Efficacy of Oligonucleotide Delivery Systems

Gene therapy requires safe and effective vectors to deliver genes to their target site of action. Non-viral gene delivery systems have attracted growing attention due to their low toxicity, low immunogenicity and ease of production compared to viral vectors. Most non-viral gene delivery systems enter cells via endocytic pathways, and their escape from endosomes is therefore crucial for successful transfection. Several reagents have been developed to promote endosomal escape, including peptides, polymers and lipids. Among these, endosome-disrupting peptides have been used in many studies, and have proven to be one of the most promising approaches to overcome endosomal entrapment and lysosomal degradation. This review provides an up-to-date summary of strategies for enhancing endosomal escape, with a focus on the modification of endosome-disrupting peptides to further increase the efficient delivery of oligonucleotides.

[Clinical and genetic features of dyskeratosis congenital with bone marrow failure in eight patients]

目的

加深对先天性角化不良（dyskeratosis congenital，DC）伴骨髓衰竭的认识。

方法

收集2010年9月30日至2015年9月30日8例伴骨髓衰竭DC患儿的临床资料，利用二代测序技术对DKC1、TERC、TERT、NOP10、NHP2、TINF2等16种端粒相关基因进行全外显子及剪接位点测序分析。

结果

8例DC患儿中男6例、女2例，中位发病月龄为42(15~60）个月。初诊血常规：中位WBC 3.99（1.26~5.44）×10⁹/L，中位中性粒细胞计数1.11(0.38~2.15）×10⁹/L，中位RBC 2.45(0.37~3.56）×10¹²/L，中位HGB 82.5(15~127) g/L，中位PLT 27（2~112）×10⁹/L。8例患儿中6例骨髓增生减低或重度减低。3例患儿检出DKC1基因突变：c.961C>A 1例，c.1058C>T 2例；4例患儿检出TINF2基因突变：c.849delC、c.844C>T、c.811C>T、c.862T>A合并c.871delA各1例；1例患儿检出TINF2基因突变（c.848C>A）合并TERT基因突变（c.1138C>T）。其中DKC c.961C>A、TINF2 c.849delC、TINF2 c.871delA突变为首次报道。7例患儿口服雄激素治疗，其中5例血常规指标改善。1例患儿死于重症感染，其余7例患儿维持治疗。

结论

DC伴骨髓衰竭以TINF2突变和DKC1突变为主。雄激素治疗对部分病例有效。

Physics of Phase Space Matching for Staging Plasma and Traditional Accelerator Components Using Longitudinally Tailored Plasma Profiles

Phase space matching between two plasma-based accelerator (PBA) stages and between a PBA and a traditional accelerator component is a critical issue for emittance preservation. The drastic differences of the transverse focusing strengths as the beam propagates between stages and components may lead to a catastrophic emittance growth even when there is a small energy spread. We propose using the linear focusing forces from nonlinear wakes in longitudinally tailored plasma density profiles to control phase space matching between sections with negligible emittance growth. Several profiles are considered and theoretical analysis and particle-in-cell simulations show how these structures may work in four different scenarios. Good agreement between theory and simulation is obtained, and it is found that the adiabatic approximation misses important physics even for long profiles.

Long-term association between dairy consumption and risk of childhood obesity: a systematic review and meta-analysis of prospective cohort studies

BACKGROUND/OBJECTIVES

Data from small-scale, short-term, clinical trials suggest a beneficial effect of dairy consumption on the risk of childhood obesity; however, the long-term association is unclear. Therefore, we aim to examine the longitudinal association between dairy consumption and the risk of overweight/obesity in children and adolescents by conducting a systematic review and meta-analysis of prospective cohort studies.

SUBJECTS/METHODS

Eligible studies were identified by searching PubMed and EMBASE through March 2015. Additional studies were retrieved via Google Scholar or a hand review of the reference lists from relevant articles. Pooled associations of interest were estimated by using a random-effects model. The heterogeneity for each pooled analysis was evaluated by I(2) statistic as well as by Cochran's Q test. Publication bias was assessed by using both Egger's and Begg's tests.

RESULTS

Ten studies comprising 46,011 children and adolescents with an average 3-year follow-up were included. As compared with those who were in the lowest group of dairy consumption, children in the highest intake group were 38% less likely to have childhood overweight/obesity (pooled odds ratio (OR)=0.62; 95% confidence interval (CI): 0.49, 0.80). With each 1 serving/day increment in dairy consumption, the percentage of body fat was reduced by 0.65% (β=0.65; 95% CI: -1.35, 0.06; P=0.07), and the risk of overweight/obesity was 13% lower (OR=0.87; 95% CI: 0.74, 0.98).

CONCLUSIONS

Accumulated evidence from prospective cohort studies suggests that dairy consumption is inversely and longitudinally associated with the risk of childhood overweight/obesity. Further studies are warranted to examine the types of dairy products in relation to the risk of childhood overweight/obesity.

Spontaneous renal hemorrhage caused by invasive mole: a case report

CASE

The authors report a case with spontaneous renal hemorrhage caused by invasive mole. The diagnosis was gestational trophoblastic disease (GTD), with metastasis to brain, kidneys, and lungs at Stage IV. The patient was given etoposide-methotrexate-actinomycin D plus cyclophosphamide-vincristine (EMACO) treatment regimen for 11 times including three times with consolidation chemotherapies. Laparoscopically-assisted vaginal hysterectomy (LAVH) + laparoscopic-assisted left renal excision + evacuation of the left perirenal hematoma were performed during the eighth chemotherapy.

CONCLUSION

Post-operational pathological examination revealed trophoblasts within the lesions present in uterine fundus and the residue images of a few trophoblasts present in the left renal mass.

Inhibitory effect of liposomal quercetin on acute hepatitis and hepatic fibrosis induced by concanavalin A

Immune response plays an important role in the development of hepatic fibrosis. In the present study, we investigated the effects of quercetin on hepatitis and hepatic fibrosis induced by immunological mechanism. In the acute hepatitis model, quercetin (2.5 mg/kg) was injected iv into mice 30 min after concanavalin A (Con A) challenge. Mice were sacrificed 4 or 24 h after Con A injection, and aminotransferase tests and histopathological sections were performed. Treatment with quercetin significantly decreased the levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Consistent with this observation, treatment with quercetin markedly attenuated the pathologic changes in the liver. A hepatic fibrosis model was also generated in mice by Con A challenge once a week for 6 consecutive weeks. Mice in the experimental group were treated with daily iv injections of quercetin (0.5 mg/kg). Histopathological analyses revealed that treatment with quercetin markedly decreased collagen deposition, pseudolobuli development, and hepatic stellate cells activation. We also examined the effects of quercetin on the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and transforming growth factor beta (TGF-β) pathways by immunohistochemistry and real-time reverse transcriptase-polymerase chain reaction (RT-PCR). NF-κB and TGF-β production was decreased after treatment with quercetin, indicating that the antifibrotic effect of quercetin is associated with its ability to modulate NF-κB and TGF-β production. These results suggest that quercetin may be an effective therapeutic strategy in the treatment of patients with liver damage and fibrosis.

Effect of daily short-duration weight-bearing on disuse-induced deterioration of musculoskeletal system

OBJECTIVES

To investigate deterioration of musculoskeletal system due to prolonged disuse and the potential of daily short-duration weight-bearing as countermeasures.

METHODS

Twenty-four adult male Sprague-Dawley rats were divided into Control Group (CG, no intervention), Tail-suspension Group (TG, tail-suspension without treatment), and Weight-Bearing Group (WBG, tail-suspension with 20 min/day, 5 days/week body weight loading). After four weeks of treatment, femur and tibia, soleus and extensor digitorum longus were evaluated for bone and muscle quality respectively. Tensile properties of bone-tendon insertion (BTI) were evaluated using patella-patellar tendon complex.

RESULTS

Disuse induced deterioration on bone, muscle, and BTI after four weeks. Compared with CG, TG and WBG showed significant decrease in bone mineral density (BMD) of trabecular bone in distal femur (4.3-15.2%), muscle mass (31.3-52.3%), muscle cross-sectional area (29.1-35%), and failure strength of BTI (23.9-29.4%). Tensile test showed that the failure mode was avulsion of bone at the BTI. No significant difference was detected between TG and WBG for all assessments on bone, muscle, and BTI.

CONCLUSIONS

Disuse caused deterioration of bone, muscle, and BTI while daily short-duration of weight-bearing did not prevent this deterioration. Mechanical stimulation with higher intensity and longer duration may be necessary to prevent musculoskeletal deterioration resulted from prolonged disuse.