Selective growth of two-dimensional phosphorene on catalyst surface

Although the study of black phosphorene (BP) and its isomers has attracted enormous attention, the method of synthesizing high-quality samples in a large area is still pending. Here we explore the potential of using the chemical vapor deposition method to synthesize large-area two-dimensional (2D) phosphorene films on metal surfaces. Our ab initio calculations show that BP can be synthesized by using tin (Sn) as a catalyst, while one of its isomers, blue phosphorene (BLP), is very possible to be synthesized by using most other metals, such as Ag and Au. Besides, our study also suggests that the large binding energy between the 2D phosphorene and the active metal substrate may prohibit the exfoliation of the 2D phosphorene for real applications and, therefore, tin, silver and gold are predicted to be the most suitable catalysts for the synthesis of BP and BLP.

Measurement of the spin temperature of optically cooled nuclei and GaAs hyperfine constants in GaAs/AlGaAs quantum dots

Deep cooling of electron and nuclear spins is equivalent to achieving polarization degrees close to 100% and is a key requirement in solid-state quantum information technologies. While polarization of individual nuclear spins in diamond and SiC (ref. ) reaches 99% and beyond, it has been limited to 50-65% for the nuclei in quantum dots. Theoretical models have attributed this limit to formation of coherent 'dark' nuclear spin states but experimental verification is lacking, especially due to the poor accuracy of polarization degree measurements. Here we measure the nuclear polarization in GaAs/AlGaAs quantum dots with high accuracy using a new approach enabled by manipulation of the nuclear spin states with radiofrequency pulses. Polarizations up to 80% are observed-the highest reported so far for optical cooling in quantum dots. This value is still not limited by nuclear coherence effects. Instead we find that optically cooled nuclei are well described within a classical spin temperature framework. Our findings unlock a route for further progress towards quantum dot electron spin qubits where deep cooling of the mesoscopic nuclear spin ensemble is used to achieve long qubit coherence. Moreover, GaAs hyperfine material constants are measured here experimentally for the first time.

Concomitant mitral valve replacement and tricuspid valvuloplasty for severe mitral stenosis

OBJECTIVE

The purpose of this work is to analyze the clinical results of treating severe mitral stenosis (MS) with mild to moderate functional tricuspid regurgitation (FTR) with mitral valve replacement (MVR) alone or together with two different methods of tricuspid valvuloplasty (TVP).

PATIENTS AND METHODS

We split 132 patients into three groups: simple MVR with 47 cases (control group), MVR+ TVP (De Vega loop reduction) with 45 cases (observation group 1) and MVR+ TVP (Edwards MC3 tricuspid forming ring implantation) with 40 cases (observation group 2).

RESULTS

As expected, surgery for both observation groups was longer than for the control group, but we found no differences in aortic clamping time, cardiopulmonary bypass time, perioperative complications, and postoperative hospital stay. We found significantly fewer complications in both observation groups compared to the control group. After surgery, the diameter of the tricuspid valve ring and the maximum reflux bundle were significantly lower in the observation groups compared to the control group.

CONCLUSIONS

Overall, the long-term clinical effect of combined MVR and TVP to treat severe MS with mild to moderate FTR is better than using the simple MVR procedure. Our results also suggest that the Edwards MC3 tricuspid forming ring implantation is superior to the De Vega loop reduction.

Bone marrow fibrosis at diagnosis predicts survival for primary acute myeloid leukemia

PURPOSE

As a desmoplastic reaction, tissue fibrosis played crucial roles in solid tumor progression, chemo-resistance, and consequently heralded poor clinical outcome. Previous studies implied the effects of marrow fibrosis on prognosis for acute lymphoblastic leukemia were disputable. In this study, we aimed to investigate the potential role of bone marrow fibrosis on clinical survival in acute myeloid leukemia (AML) patients.

METHODS

Bone marrow fibrosis (evaluated as reticulin fiber density, RFD) in bone marrow sections was evaluated at diagnosis via computer technology. Receiver operating characteristic curve (ROC) was used to analyze the predictive value of RFD for relapse and survival status. Kaplan-Meier method was used to estimate survival rates per subgroup between patients with different RFD. Cox proportional hazard regression was used to model the overall survival.

RESULTS

High RFD at diagnosis in bone marrow sections from primary AML might predict early relapse and shorter survival (P = 0.003 and 0.001, respectively). The optimal cutoff value of RFD at diagnosis was determined to be 7.2%. Furthermore, the Kaplan-Meier analysis indicated that patients with high marrow RFD had shorter relapse-free survival (RFS) and overall survival (OS) than patients with low RFD (P = 0.007 and 0.000, respectively). Multivariate analysis suggested that similar with cytogenetics, marrow RFD at diagnosis was an independent prognostic factor for RFS [HR 0.564, 95% confidence interval (CI) 0.338-0.940, P = 0.028] and OS (HR 0.457, 95% CI 0.225-0.929, P = 0.031) in primary AML patients.

CONCLUSIONS

Our data suggest that marrow RFD before treatment should be seemed as prognostic factor in primary AML, it may provide valuable clues for developing new targeted therapy.

[Small incision combined with PVC slice through suture in the treatment of auricular pseudocyst in 55 patients]

Objective:To study the effect of small incision combined with PVC slice through suture in the treatment of auricular pseudocyst.Method:The clinical data of 55 patients with auricular pseudocyst were analyzed retrospectively. The operation method of small incision combined with PVC was adopted. The anterior cartilage of the cyst was not need to remove and the integrity of the auricle stent and the elasticity of the auricle were preserved. Postoperative use of pruning PVC slice through the suture fixed pressure, then observe the recovery of the ear.Result:Fifty-five cases (57 ears) were cured in one time,the cyst disappeared and the auricle shape recovered well. All patients were followed-up for 6-12 months, no recurrence.Conclusion:The combination of small incision and PVC slice through the suture treatment of auricular pseudocyst, the operation is simple, short course, good effect, the patient pain is small, not easy to relapse, safe and reliable, maintaining the original physiological function and natural appearance. It is worthy in clinical application.

[Bleeding control of periodontal mechanical therapy for patients taking aspirin]

OBJECTIVE

To investigate the feasibility of periodontal mechanical therapy for chronic periodontitis and coronary heart disease patients with low dose of aspirin.

METHODS

Sixty nine chronic periodontitis patients with coronary heart disease were randomly selected as the experimental group (medication group, group A), the control group (withdrawal group, group B) including 20 chronic periodontitis patients with coronary artery disease, stopping the drug for one week and another control group with 50 chronic periodontitis patients (group C). The three groups were examined with pocket probing, and received supragingival scaling, subgingival scaling, and root planning. Local bleeding after operation was observed. In 30 minutes after periodontal mechanical treatment, there was still a need to take some hemostatic measures (containing the oxidized cellulose putting in the periodontal pocket, gauze oppressing, and suturing). Nd:YAG laser was used to stop bleeding 60 minutes after operation.

RESULTS

At baseline, there was no significant difference in the three groups, as to the plaque index(PLI), the probing depth (PD), and the attachment loss (AL). The bleeding index (BI)in group A was significantly higher than that in group C (P=0.024), higher than that in group B (P=0.088). The platelet maximum aggregation rate (Agg(max)) was detected in some subjects. The average Agg(max) value group A was 15.2%, which was much greater than that in group B (60.7%) and group C (62.5%). The three groups were all safe in the treatment of periodontal therapy. There were five cases of active bleeding in group A, one case in group B and one case in group C in 30 minutes after operation. In 60 minutes after operation, there was one case of bleeding actively in group A. Nd:YAG laser was used to stop bleeding successfully.

CONCLUSION

The chronic periodontitis and coronary heart disease patients with long-term oral administration of low dose of aspirin can be safely treated with periodontal mechanical treatment, and the effect of local hemostasis is positive without stopping the drug.

Molecular and pathological evaluation of cryopreserved colorectal cancerous tissues: Effects of freezing method and cryoprotection

BACKGROUND

Snap freezing and RNAlater stabilization are methods that were wildly used in biospecimen depositories to preserve cancer tissues. Both methods have its own limitations. An ideal method for preservation of diseased tissues should permit the broader uses of stored tissue samples, including not just for molecular diagnostic analysis, histopathological evaluation, but also for the recovery of functional live cells and tissues as well as the regeneration of patient-derived xenograft (PDX) models for the drug screening study.

MATERIALS AND METHODS

This study investigated molecular and pathological evaluation of cryopreserved colorectal cancer tissues, with an emphasis on effects of freezing method and cryoprotection. Global gene expression analysis with microarrays and histological examination of tissue samples were performed to compare tissue specimens after snap freezing, cryoprotectant permeation and subsequent cryopreservation.

RESULTS

Compared with the fresh tissue samples (immediately stabilized in RNAlater after collection), samples preserved by snap freezing exhibited the largest number of differentially-expressed genes. Some genes relate to neuron, drug addiction and drug binding, but the rest of differentially-expressed genes were functionally dispersive. Cryoprotectant permeation into tissue samples and subsequent cryopreservation via a rate-controlled freezing resulted in much less differentially expressed genes. Histological structures of tissue specimens were both well preserved by snap freezing and cryoproservation.

CONCLUSION

Snap freezing may not be as reliable as commonly considered. The pilot study demonstrates the feasibility of using cryopreservation to retain viable diseased tissues for multiple applications.

Heavy metals in composts of China: historical changes, regional variation, and potential impact on soil quality

Composts are considered one of major sources that contribute heavy metals to the environment. The objective of this study was to investigate historical changes and spatial variation of metal concentrations in Chinese composts by analysing representative compost samples and published data from 2002 to 2013. Mean concentrations of cadmium (Cd), chromium (Cr), lead (Pb), arsenic (As), mercury (Hg), zinc (Zn), nickel (Ni), and copper (Cu) in the composts were 2.42, 35.52, 32.38, 16.33, 0.32, 258.1, 9.71, and 72.24 mg kg^-1, respectively. The percentages of samples with metal concentration exceeding critical levels of Chinese standards for organic fertilizers (NY525-2012) were 28.7, 18.3, 9.6, 1.7, and 0.9%, respectively, for Cd, As, Pb, Cr, and Hg. Modelling predicts that it would take 18, 24, 29, and 48 years for Cu, Zn, Hg, and Cd to reach Category I Environmental Capacity of China (GB15618-1995) according to current application rate. During the 2002-2013 period, concentration of Cd in composts tended to decrease with time, whereas those of Zn, Cu, and As were opposite, which is likely due to less or no control for these elements. Concentrations of Cu, Zn, As, and Cd were generally higher in composts from the economically developed regions in China, where more commercial farms were built that use metal-spiked feeds. Manures from the commercial farms generally had higher metal concentration, as compared to the subsistence farms. Further research is needed to monitor metal concentrations from source materials to composts and assess long-term impact of compost application on soil quality.

Association of decreased serum sTREM-1 level with the severity of coronary artery disease: Inhibitory effect of sTREM-1 on TNF-α- and oxLDL-induced inflammatory reactions in endothelial cells

Soluble triggering receptor expressed on myeloid cells 1 (sTREM-1) is closely involved in autoimmune diseases and inflammatory reactions. We aimed to investigate whether serum sTREM-1 is related to coronary artery disease (CAD) and to evaluate the biological effects of sTREM-1 in cell experiments.This cross-sectional study included 263 consecutive patients with angiographically documented CAD, who were admitted for diagnosis and interventional treatment of CAD (CAD group), with 162 participants without CAD serving as controls (control group). Serum levels of sTREM-1 and high sensitivity C reactive protein (hsCRP) were determined in all participants. In cell experiments, the influence of sTREM-1 on tumor necrosis factor-α (TNF-α)- or oxidized low-density lipoprotein (oxLDL)-induced inflammatory reactions was evaluated in human umbilical vein endothelial cells (HUVECs).Serum level of sTREM-1 was significantly lower in CAD patients than in controls (P < 0.001). sTREM-1 values were related to the number of diseased coronary arteries (Spearman r = -0.413, P < 0.001) and the severity represented by Gensini score (Pearson r = -0.336, P < 0.001). Multivariable logistic regression analysis revealed that decreased sTREM-1 were independent determinants of CAD (OR = 0.428, P < 0.001). In cell experiments, recombinant sTREM-1 protein concentration-dependently inhibited the expression of IL-1β, IL-6, TNF-α, VCAM-1, and ICAM-1 induced by TNF-α or oxLDL in HUVECs.This study demonstrates that decreased serum sTREM-1 level is significantly associated with the presence and severity of CAD. sTREM-1 restrains inflammatory reaction in endothelial cells, suggesting that it might be a potential vascular protective factor.

The influence of various biochars on the bioaccessibility and bioaccumulation of PAHs and potentially toxic elements to turnips (Brassica rapa L.)

The influence of amending a contaminated soil with different dry-pyrolyzed biochars on the bioaccessibility and biouptake of polycyclic aromatic hydrocarbons (PAH) and potentially toxic elements (PTE) in turnip (Brassica rapa L.,) was investigated. This is the first study to examine the influence of biochar amendments on turnips grown in a contaminated soil. The biochars came from different local feedstocks, including sewage sludge biochar (SSBC), soybean straw biochar (SBBC), rice straw biochar (RSBC) and peanut shell biochar (PNBC). The biochars were applied to soil at 2% and 5% amendments, and the resulting influence on various soil and porewater properties were quantified. The bioaccessible concentrations of PAHs in soil and their bioaccumulation in B. rapa L. significantly (P < 0.05) decreased in the biochar amended soils. Biochar additions significantly (P ≤ 0.05) reduced the bioaccumulation of PTEs (As, Cd, Cu, Pb and Zn) in B. rapa L, though not as much as for PAHs. The most effective biochar at reducing both PAHs and PTEs was PNBC (P ≤ 0.05). Amendments of 5% biochar were more effective at reducing contaminant bioaccessibility than amendments at 2% (P < 0.05). Crop yield, however, increased the most for the 2% biochar amendments, in particular for SSBC (with a 49% increase in crop yield compared to the non-amended soil). Therefore, which biochar would be the most advantageous in this system would require a cost-benefit analysis between increasing crop yield (best achieved with 2% SSBC amendments) and decreasing the PAH and PTE uptake (best achieved with 5% PNBC amendments).

Serum apelin is associated with left ventricular hypertrophy in untreated hypertension patients

BACKGROUND

Apelin is an endogenous ligand for the G protein-coupled receptor APJ. The association between apelin and cardiac modeling has been reported. However, if serum apelin affect the left ventricular hypertrophy (LVH) prevalence in hypertensive patients remains unknown.

METHODS

We enrolled 344 untreated hypertensive patients. The presence of LVH was determined by echocardiography. The blood was drawn from these patients and serum apelin level was detected. To study the direct effect of apelin on cardiac hypertrophy, cardiomyocytes were cultured and were transfected with apelin gene. Morphometric analysis and measurement of protein contain per cell were then performed.

RESULTS

We observed a significantly lower serum apelin level in hypertensive patients with LVH compared with those without LVH. Receiver operating characteristic analyses shows that serum apelin level is robust in discriminating patients with LVH from those without. Our in vitro study showed that cellular protein content and cellular size was increased by Ang II treatment, which can be markedly inhibited by the apelin over-expression in cultured cardiomyocytes.

CONCLUSION

Our clinical date established a link between apelin and LVH, suggesting serum apelin may be used as a predicator for LVH prevalence in hypertensive patients. The direct evidence in vitro suggest apelin pathway is involved in the cardiomyocyte adaption to hypertrophic stimuli.

Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s]=200 GeV

We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05.

Rapid atraumatic sex identification of developmental day 14-16 mice

Embryonic mice have been used widely to study organ development. Days 14-16 are critical for sex organ development and differentiation in mice. Current methods for sex identification are limited. Even the simplest polymerase chain reaction method may injure the embryo. We determined that morphologic analysis of embryonic mammary anlagen could be used for rapid atraumatic sex identification of day 14-16 mice. The accuracy of our method was verified by molecular and anatomical approaches.

Insights into carbon nanotube and graphene formation mechanisms from molecular simulations: a review

The discovery of carbon nanotubes (CNTs) and graphene over the last two decades has heralded a new era in physics, chemistry and nanotechnology. During this time, intense efforts have been made towards understanding the atomic-scale mechanisms by which these remarkable nanostructures grow. Molecular simulations have made significant contributions in this regard; indeed, they are responsible for many of the key discoveries and advancements towards this goal. Here we review molecular simulations of CNT and graphene growth, and in doing so we highlight the many invaluable insights gained from molecular simulations into these complex nanoscale self-assembly processes. This review highlights an often-overlooked aspect of CNT and graphene formation-that the two processes, although seldom discussed in the same terms, are in fact remarkably similar. Both can be viewed as a 0D → 1D → 2D transformation, which converts carbon atoms (0D) to polyyne chains (1D) to a complete sp(2)-carbon network (2D). The difference in the final structure (CNT or graphene) is determined only by the curvature of the catalyst and the strength of the carbon-metal interaction. We conclude our review by summarizing the present shortcomings of CNT/graphene growth simulations, and future challenges to this important area.

ΛΛ Correlation function in Au+Au collisions at √[S(NN)]=200 GeV

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200  GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.