Correction: Transport mechanisms in a puckered graphene-on-lattice

Correction for 'Transport mechanisms in a puckered graphene-on-lattice' by T. Xu et al., Nanoscale, 2018, 10, 7519-7525.

A theoretical study of Ar8+-acetylene collisions at 1.2 MeV: Ionization and dissociation dynamics

We theoretically study Ar⁸⁺-induced dissociation of C₂H₂ molecule at 1.2 MeV using the time-dependent density-functional theory non-adiabatically coupled to nuclear dynamics. We find that molecular dissociation depends strongly on the ionization at the initial stage and the collision configuration. A detailed analysis shows a correspondence between the charge state of [C₂H₂]^q+ and the final fragments. A remarkable impact parameter effect provides deep insights of bond breakup and electronic transport. We analyze two typical sequential dissociation channels reported in experiments by tracking structural and electronic dynamics in real time. Our results provide better understanding of experiments. Moreover, the comparison between various exchange-correlation functionals reveals that electrons' correlation and self-interaction do not significantly impact the initial ionization and fragment distribution in the present study.

Multivariate analysis of inflammatory endotypes in recurrent nasal polyposis in a Chinese population

BACKGROUND

Chronic rhinosinusitis with nasal polyps (CRSwNP) remains a challenging clinical problem due to its propensity for recurrence. However, data on the frequency of CRSwNP recurrence after surgery in China are rare.

METHODS

78 CRSwNP patients undergoing functional endoscopic sinus surgery were followed-up for 8 years and classified into recurrent and non-recurrent groups. A cluster analysis of the CRSwNP based on inflammatory endotypes was performed, and the endotypes were secondarily matched with clinical phenotypes.

RESULTS

The recurrence rate of CRSwNP in Southwest China was 21.8% over 8 years post-surgery. The CRSwNP was classified into 4 clusters: cluster 1 (higher expression of IL-5, IgE, and ECP and high positivity rate for SE-IgE); cluster 2 (higher concentrations of IL-6, IL-8 and MPO); cluster 3 (higher concentrations of TNF-alpha; and IFN-gamma); and cluster 4 (higher expression of IL-17). Cluster 1 (type-2 inflammation) exhibited the highest recurrence rate, co-morbid asthma and atopy. Notably, the ECP/MPO ratio increased significantly in patients with non-type-2 recurrent CRSwNP 8 years after the first surgery.

CONCLUSION

Different inflammatory endotypes of CRSwNP exhibited clearly different prognoses. The type-2 subgroup had high recurrence and co-morbid asthma rates comparable to the rates reported in Western countries.

Local Schottky contacts of embedded Ag nanoparticles in Al2O3/SiN x :H stacks on Si: a design to enhance field effect passivation of Si junctions

This paper describes an original design leading to the field effect passivation of Si n⁺-p junctions. Ordered Ag nanoparticle (Ag-NP) arrays with optimal size and coverage fabricated by means of nanosphere lithography and thermal evaporation, were embedded in ultrathin-Al₂O₃/SiN _x :H stacks on the top of implanted Si n⁺-p junctions, to achieve effective surface passivation. One way to characterize surface passivation is to use photocurrent, sensitive to recombination centers. We evidenced an improvement of photocurrent by a factor of 5 with the presence of Ag NPs. Finite-difference time-domain (FDTD) simulations combining with semi-quantitative calculations demonstrated that such gain was mainly due to the enhanced field effect passivation through the depleted region associated with the Ag-NPs/Si Schottky contacts.

Transport mechanisms in a puckered graphene-on-lattice

Understanding the fundamental properties of graphene when its topography is patterned by the use of a compliant substrate is essential to improve the performances of graphene sensors. Here we suspend a graphene monolayer on SiO2 nanopillar arrays to form a puckered graphene-on-lattice and investigate the strain and electrical transport at the nanoscale. Despite a nonuniform strain in the graphene-on-lattice, the resistivity is governed by thermally activated transport and not the strain. We show that the high thermal activation energy results from a low charge carrier density and a periodic change of the chemical potential induced by the interaction of the graphene monolayer with the nanopillars, making the use of graphene-on-lattice attractive to further increase the electrical response of graphene sensors.

Systematic review with meta-analysis: effectiveness and tolerability of interferon-free direct-acting antiviral regimens for chronic hepatitis C genotype 1 in routine clinical practice in Asia

BACKGROUND

Direct-acting antiviral (DAA) regimens have shown high efficacy and tolerability for patients with HCV genotype 1/1b (GT1/1b) in clinical trials. However, robust real-world evidence of interferon (IFN)-free DAA treatment for HCV GT1-infected patients in Asia is still lacking.

AIM

To systematically review and meta-analyse the effectiveness and tolerability of IFN-free DAA therapy for HCV GT1 infection in Asia.

METHODS

We included studies that enrolled adult patients with HCV GT1 infection in routine clinical practice in Asia, using IFN-free DAA regimens, and reported sustained virological response (SVR) after 12/24 weeks end-of-treatment by 31 May 2017. The pooled SVR rates were computed with a random-effects model. Subgroup analysis and meta-regression as previously registered in PROSPERO were performed to determine how pre-planned variables might have affected the pooled estimates.

RESULTS

We included 41 studies from eight countries and regions, comprising of 8574 individuals. The pooled SVR rates for GT1 were 89.9% (95% CI 88.6-91.1, I²  = 55.1%) with daclatasvir/asunaprevir (DCV/ASV) and 98.1% (95% CI 97.0-99.0, I²  = 41.0%) with ledipasvir/sofosbuvir ± ribavirin (LDV/SOF ± RBV). Baseline cirrhosis but not prior treatment history and age, attenuated the effectiveness of both regimens. Baseline resistance associated substitutions (RASs) severely attenuated SVR of DCV/ASV (65.4% vs 94.3%, P < 0.001) and only minimally with LDV/SOF ± RBV (94.5% vs 99.2%, P = 0.003). Patients with renal dysfunction treated with DCV/ASV showed a higher SVR rate (93.9% vs 89.8%, P = 0.046). Patients with hepatocellular carcinoma (HCC) LDV/SOF ± RBV achieved a lower SVR than those without HCC (94.1% vs 98.7%, P = 0.001).

CONCLUSION

All oral DAA treatment of HCV GT1 resulted in high cure rates in Asian patients in routine clinical practice setting including elderly patients and those with end-stage renal disease.

[The role and significance of digital reconstruction technique in liver segments based on portal vein structure]

Objective: To study the segment of liver according to the large amount of three-dimensional(3D) reconstructive images of normal human livers and the vascular system, and to recognize the basic functional liver unit based on the anatomic features of the intrahepatic portal veins. Methods: The enhanced CT primitive DICOM files of 1 260 normal human livers from different age groups who treated from October 2013 to February 2017 provided by 16 hospitals were analyzed using the computer-aided surgery system.The 3D liver and liver vascular system were reconstructed, and the digital liver 3D model was established.The vascular morphology, anatomical features, and anatomical distributions of intrahepatic portal veins were statistically analyzed. Results: The digital liver model obtained from the 3D reconstruction of CAS displayed clear intrahepatic portal vein vessels of level four.Perform a digital liver segments study based on the analysis of level four vascular distribution areas.As the less anatomical variation of left hepatic portal vein, the liver was classified into four types of liver segmentation mainly based on right hepatic portal vein.Type A was similar to Couinaud or Cho's segmentation, containing 8 segments(537 cases, 42.62%). Type B contained 9 segments as there are three ramifications of right-anterior portal vein(464 cases, 36.82%). The main difference for Type C was the variation of right-posterior portal vein which was sector shape(102 cases, 8.10%). Type D contained the cases with special portal vein variations, which needs three-dimensional simulation to design individualized liver resection plan(157 cases, 12.46%). These results showed that there was no significant difference in liver segmental typing between genders(χ(2)=2.179, P=0.536) and did not reveal any significant difference in liver segmental typing among the different age groups(χ(2)=0.357, P=0.949). Conclusions: The 3D digital liver model can demonstrate the true 3D anatomical structures, and its spatial vascular variations.The observation of anatomic features, distribution areas of intrahepatic portal veins and individualized liver segmentation achieved via digital medical 3D visualization technology is of great value for understand the complexity of liver anatomy and to guide the precise hepatectomy.

[Effect of different anesthetic methods on postoperative outcomes in elderly patients undergoing hip fracture surgery]

OBJECTIVE

To investigate the effect of general or regional anesthesia on postoperative cardiopulmonary complications and inpatient mortality after hip fracture surgery in elderly patients.

METHODS

A retrospective analysis was conducted according to the medical records of 572 elderly patients with hip fractures admitted to our hospital from January 1, 2005 to December 31, 2014. The age, gender, preoperative comorbidities, length of preoperative bedridden time, mechanism of injury, surgical types, anesthetic methods, major postoperative complications and inpatient mortality were recorded. Multivariate Logistic regression analysis was applied to analyze the impact of different anesthetic methods on inpatient mortality in these patients.

RESULTS

Of the 572 patients, 392 (68.5%) received regional anesthesia. Inpatient death occurred in 8 (8/572, mortality: 1.4%), including 5 cases of RA group (5/392, mortality: 1.3%) and 3 cases of GA group (3/180, mortality: 1.7%). There was no statistically significant difference between the two groups in inpatient mortality (P>0.05). Multiple Logistic regression analysis showed that gender (odds ratio: 0.18, 95% CI: 0.03-1.05, P=0.057), age (odds ratio: 1.22, 95% CI: 1.07-1.38, P=0.002), preoperative pulmonary comorbidities (odds ratio: 12.09, 95% CI: 2.28-64.12, P=0.003) and surgical types (odds ratio: 9.36, 95% CI: 1.34-64.26, P=0.024) were risk factors for inpatient mortality. Postoperative cardiovascular complications occurred in 36 patients (36/572, morbidity: 6.3%), with 19 patients in RA group (19/392, morbidity: 4.8%),and 17 patients in GA group (17/180, morbidity: 9.4%). Multiple Logistic regression analysis showed that age (odds ratio: 1.13, 95% CI: 1.07-1.19, P<0.001), hypertension (odds ratio: 2.72, 95% CI: 1.24-5.96, P=0.012) and preoperative cerebral comorbidities (odds ratio: 2.11, 95% CI: 0.99-4.52, P=0.054) were risk factors for postoperative cardiovascular complications. Postoperative pulmonary complications occurred in 56 patients (56/572, morbidity: 9.8%), with 19 patients in RA group (19/392, morbidity: 4.8%), and 37 patients in GA group (37/180, morbidity: 20.6%). Multiple Logistic regression analysis showed that age (odds ratio: 1.13, 95% CI: 1.07-1.19, P<0.001), preoperative pulmonary comorbidities (odds ratio: 2.89, 95% CI: 1.28-7.05, P=0.020), length of preoperative bedridden time (odds ratio: 1.11, 95% CI: 1.04-1.18, P=0.003) and anesthetic methods (odds ratio: 5.86, 95% CI: 2.98-11.53, P<0.001) were risk factors for postoperative pulmonary complications.

CONCLUSION

General anesthesia may not affect the inpatient mortality after hip fracture surgery in elderly patients. Regional anesthesia is associated with a lower risk of pulmonary complications after surgical procedure compared with general anesthesia.

[Autophagy regulated by JWA influenced sensitivity of esophageal cancer to cisplatin]

Objective: To explore the effect of JWA on cisplatin sensitivity and its potential molecular mechanism in esophageal cancer. Methods: The siRNA was used to inhibit the JWA expression, then cisplatin sensitivity and LC3 (autophagy related protein) expression levels were observed in TE1 cells.Further, the effect of autophagy inhibitor tamoxifen (3-MA) on above process was determined.Cisplatin sensitivity of 20 fresh esophageal cancer samples was evaluated by histoculture drug response assay (HDRA). Result: Silencing JWA gene increased the sensitivity of TE1 cells to cisplatin (P<0.05), and decreased the LC3-Ⅰ and LC3-Ⅱ proteins induced by cisplatin.Furthermore, combined with 3-MA increased the inhibition rate of cisplatin in JWA silencing group (P<0.05). Additionally, the inhibition rate of cisplatin on tissues with low JWA expression were higher than those with high expression (45.6% vs 25.6%, P=0.005). Conclusions: JWA could influence the cisplatin sensitivity by regulating autophagy in esophageal cancer.

Experimental investigations and phase-field simulations of triple-phase-separation kinetics within liquid ternary Co-Cu-Pb immiscible alloys

The phase-separation kinetics and microstructure evolution mechanisms of liquid ternary Co_{43}Cu_{40}Pb_{17} immiscible alloys are investigated by both the drop tube technique and phase-field method. Two successive phase separations take place during droplet falling and lead to the formation of a three-phase three-layer core-shell structure composed of a Co-rich core, a Cu-rich middle layer, and a Pb-rich shell. The Pb-rich shell becomes more and more conspicuous as droplet diameter decreases. Meanwhile, the Co-rich core center gradually moves away from the core-shell center. Theoretical analyses show that a larger temperature gradient inside a smaller alloy droplet induces the accelerated growth of the surface segregation shell during triple-phase separation. The residual Stokes motion and the asymmetric Marangoni convection result in the appearance of an eccentric Co-rich core and the core deviation degree is closely related to the droplet size and initial velocity. A three-dimensional phase-field model of ternary immiscible alloys, which considers the successive phase separations under the combined effects of Marangoni convection and surface segregation, is proposed to explore the formation mechanisms of three-phase core-shell structures. The simulated core-shell morphologies are consistent with the experimental observations, which verifies the model's validity in reproducing the core-shell dynamic evolution. Numerical results reveal that the development of three-phase three-layer core-shell structures can be attributed to the primary and then secondary phase separations dominated simultaneously by Marangoni convection and surface segregation. Furthermore, the effects of droplet temperature gradient on the growth kinetics of the surface segregation shell are analyzed in the light of phase-field theory.

[Enhanced recovery after surgery for the gastrointestinal surgery]

It has already been ten years since the concept of enhanced recovery after surgery (ERAS) was introduced in China. The ERAS protocol focuses on relieving surgical stress and accelerating physiological recovery. From our perspective, besides the post hospital stay, it would be better to evaluate patient's recovery by different indicators. It is important to improve the compliance of ERAS protocol. The guideline-related factors, administration, medical staff and patients have impact on compliance. Integrating stakeholders, strengthening communication and cooperation among multidiscipline teams, combining theory with practice would facilitate use of ERAS protocol in clinical settings.

Answers to if the Lead Aprons are Really Helpful in Nuclear Medicine from the Perspective of Spectroscopy

Wearing lead X-ray-protective aprons is a routine in nuclear medicine department in parts of China. However, the staff are often perplexed by questions such as if it is imperative to wear aprons when injecting radioactive drugs, how much radiation dosage can be shielded and if the apron will produce secondary radiation instead? To answer these questions, a semiconductor detector was employed to record different gamma and X-ray spectra with and without the lead apron or lead sheet. Then, we could estimate the signal shielding ratio to different photons for the lead apron and compare with the hospitals measured data. In general, the two results coincided well. The spectral results showed that the detrimental secondary X-rays irradiation rises when the energy of gamma rays exceeds the K absorption edge of lead (88 keV). Moreover, the aprons are not so effective for gamma rays of 364 keV emitted from 131I and 511 keV emitted from the positron radioactive nuclides. This work is purely a physical measurement in the laboratory. To the best of our knowledge, this is the first quantitative study on the level of gamma rays protection offered by the medical lead aprons and the importance of the spectroscopic measurements is discussed in this paper.

A numerical simulation of acoustic field within liquids subject to three orthogonal ultrasounds

When one beam of ultrasound propagates along a single direction in liquids, the cavitation effect is always confined to a limited volume close to the ultrasonic source. This greatly limits the application of power ultrasound in liquid processing and materials fabrication. In this study, a methodology for applying three orthogonal ultrasounds within liquids has been proposed. By solving the Helmholtz equation, the sound field distribution characteristics are investigated in 1D (one dimensional), 2D (two dimensional) and 3D (three dimensional) ultrasounds at their resonant frequencies, which show that the coherent interaction of three beams of ultrasounds is able to strikingly promote the sound pressure level and reinforce the mean acoustic energy density as compared with that in 1D case. Hence, the potential cavitation volume is enlarged remarkably. This opens new possibilities for the design and optimization of ultrasonic technology in fabricating materials.

Liquid Supercoolability and Synthesis Kinetics of Quinary Refractory High-entropy Alloy

The high-entropy configuration of equiatomic multicomponent alloys opens an effective access to the development of advanced materials. Here we report the synthesis of a new quinary refractory WMoTaNbZr high-entropy alloy under electrostatic levitation condition. It showed a high liquidus temperature of 2686 K and achieved a maximum supercooling of 640 K (0.24 T_L) at molten state. The containerless measurements revealed a linear increasing tendency for both its liquid state density and the specific heat to emissivity ratio versus alloy supercooling. A high-entropy body-centered cubic (HEB) phase dominated its phase constitution despite the formation of a negligible amount of solid solution (Zr) phase. The dendritic growth of HEB phase always governed the crystallization process, attained a fastest growth velocity of 13.5 m/s and displayed a power function relation to alloy supercooling. The high speed videographic research of recalescence phenomenon indicated Johnson-Mehl-Avrami type transition kinetics for its rapid solidification process. As supercooling increases, the microstructures of primary HEB phase were refined conspicuously and exhibited an obvious solute trapping effect of the segregative Zr component. Meanwhile, the Vickers hardness of HEB phase displayed the rising tendency with supercooling.

Three orthogonal ultrasounds fabricate uniform ternary Al-Sn-Cu immiscible alloy

The production of Al based monotectic alloys with uniform microstructure is usually difficult due to the large density difference between the two immiscible liquid phases, which limits the application of such alloys. Here, we apply three orthogonal ultrasounds during the liquid phase separation process of ternary Al_71.9Sn_20.4Cu_7.7 immiscible alloy. A uniform microstructure consisting of fine secondary (Sn) phase dispersed on Al-rich matrix is fabricated in the whole alloy sample with a large size of 30 × 30 × 100 mm. The numerical calculation results indicate that the coupled effect of three ultrasounds promotes the sound pressure level and consequently enlarges the cavitation zone within the alloy melt. The strong shockwaves produced by cavitation prevent the (Sn) droplets from coalescence, and keep them suspended in the parent Al-rich liquid phase. This accounts for the formation of homogeneous composite structures. Thus the introduction of three orthogonal ultrasounds is an effective way to suppress the macrosegregation caused by liquid phase separation and produce bulk immiscible alloys with uniform structures.