Kinetic control of tunable multi-state switching in ferroelectric thin films

Deterministic creation of multiple ferroelectric states with intermediate values of polarization remains challenging due to the inherent bi-stability of ferroelectric switching. Here we show the ability to select any desired intermediate polarization value via control of the switching pathway in (111)-oriented PbZr_0.2Ti_0.8O₃ films. Such switching phenomena are driven by kinetic control of the volume fraction of two geometrically different domain structures which are generated by two distinct switching pathways: one direct, bipolar-like switching and another multi-step switching process with the formation of a thermodynamically-stable intermediate twinning structure. Such control of switching pathways is enabled by the competition between elastic and electrostatic energies which favors different types of ferroelastic switching that can occur. Overall, our work demonstrates an alternative approach that transcends the inherent bi-stability of ferroelectrics to create non-volatile, deterministic, and repeatedly obtainable multi-state polarization without compromising other important properties, and holds promise for non-volatile multi-state functional applications.

The use of ferroeletric materials for multi-state device applications is still challenging. Here, the authors present a mechanism to stabilize non-volatile polarization states by populating volume fractions of two domain structures in PbZr_0.2Ti_0.8O₃ via kinetic control of switching pathways.

[Comparison of preoperative planning of radioactive seed implantation for pelvic wall recurrent gynecological malignant tumors between 3D-printing non-coplanar template and 3D-printing coplanar template]

Objective: To compare the difference of preoperative planning parameters between 3D-printing non-coplanar template (3D-PNCT) and 3D-printing coplanar template (3D-PCT) in the treatment of pelvic wall recurrent gynecological malignant tumor with radioactive seeds implantation, and to guide the clinical application. Methods: From January 2016 to March 2018, 33 patients with pelvic wall recurrent gynecological malignant tumor were treated with radioactive seeds implantation assisted by 3D-printing template and in Peking University Third Hospital. All patients underwent 3D-PNCT and 3D-PCT preoperative planning. The D(90) of target remained similar for the same patient. The parameters were compared with Wilcoxon test or Kruskal-Wallis test. Results: D(90) was similar between the two groups (P>0.05). The number of inserting needles through intestine and bone in 3D-PNCT group was less than that in 3D-PCT group (0 (0-13), 0 (0-25), Z=-2.941, P<0.05;0 (0-3), 0 (0-25), Z=-2.232, P<0.05). Conclusion: For patients with gynecological malignancies with pelvic recurrence, both of the two peroperative plans could achieve prescription dose, but 3D-PNCT is more safer.

[CT-guidance interstitial Iodine-125 seed brachytherapy as a salvage therapy for recurrent head and neck carcinoma]

Objective: To investigate the efficacy of CT-guidance interstitial Iodine-125 seed brachytherapy as a salvage therapy for recurrent head and neck carcinoma. Methods: A total of 122 patients who had been treated for recurrent head and neck carcinoma with CT-guided Iodine-125 seed permanent implantation were conducted a retrospective analysis at Peking University Third Hospital from February 2003 to December 2015. The study included 78 male and 44 female patients. Of the 122 patients, 76 had undergone radical surgery, 106 had received EBRT. Among the patients who underwent EBRT, the total dose delivered to PTV ranged from 30 to 140 Gy (median, 68.4 Gy). The actuarial median number of the implanted Iodine-125 seeds was 38 (range, 5-158). The specific activity of Iodine-125 seeds ranged from 14.8 to 28.9 MBq/seed (median, 22.2 MBq). The evaluation of post plan showed the actuarial D90 ranged from 46 to 282 Gy (median, 121 Gy). The overall local control and survival times were determined by using the Kaplan-Meier method from SPSS 13.0.Univariate analysis was performed on the local control rate and overall survival rate. Results: Tumor responses rate was 75.4%. The median local control time was 10.0 months (95% CI 9.8-24.2 months), and the 1-, 2-, 3-, and 5-year local control were 41.9%, 21.2%, 3.7%, and 3.7%, respectively. Univariate analysis showed that the local control in D90≥120 Gy group had an increasing tendency, but no statistical difference were found. The effect of local control in the squamous cell carcinoma group was slightly worse than that in the non-squamous cell carcinoma group (P=0.032). Multi-factor analysis showed that the effect of local control in the squamous cell carcinoma group was slightly poor (P=0.03). The median survival time was 14 months (95% CI 14.4-35.8 months), and the 1-, 2-, 3- and 5-year survival rate were 51.5%, 34.2%, 19.4%, and 19.4%, respectively. The three factors, such as the tumor responses, KPS status before the seed implantation, and the D90 after the seed implantation, had a tendency to improve the total survival, but there was still no statistical differences. Multivariate analysis showed no clear influence factors. Conclusions: Interstitial permanent Iodine-125 seed implantation is an effective salvage re-irradiation modality for recurrent head and neck carcinoma after previous surgery and/or EBRT. CT image-guided method could yield the reliable seeds configuration and accurate dose distribution.

Detection of N-glycolylneuraminic acid biomarkers in sera from patients with ovarian cancer using an engineered N-glycolylneuraminic acid-specific lectin SubB2M

N-glycolylneuraminic acid (Neu5Gc)-containing glycans are a prominent form of aberrant glycosylation found in human tumor cells and have been proposed as cancer biomarkers. The B subunit of the subtilase cytotoxin (SubB) produced by Shiga toxigenic Escherichia coli recognises Neu5Gc containing glycans. We have previously engineered this lectin, SubB2M, for greater specificity and enhanced recognition of Neu5Gc-containing glycans. Here we further explore the utility of SubB2M to detect Neu5Gc tumor biomarkers in sera from patients with ovarian cancer. Using surface plasmon resonance (SPR) we show that SubB2M can detect the established ovarian cancer biomarker, CA125, in a highly sensitive and specific fashion in the context of human serum. These studies established conditions for screening serum samples from patients with ovarian cancer for Neu5Gc glycans. We found that serum from patients with all stages of ovarian cancer had significantly elevated mean levels of Neu5Gc glycans compared to normal controls. Serum from patients with late stage disease (stages IIIC, IV) had uniformly elevated levels of Neu5Gc glycans. Detection of Neu5Gc-glycans using SubB2M has the potential to be used as a diagnostic ovarian cancer biomarker, as well as a tool for monitoring treatment and disease progression in late stage disease.

[Brachytherapy treatment planning calculation (125)I particle esophageal stent dosimetric study]

Objective: To investigate the dosimetric distribution characteristics of (125)I seed stents with different seed spacing, diameter and length, as well as different (125)I seed activity. The dosimetry table of (125)I seed esophageal stent was derived to provide dosimetry for its clinical application. Methods: The self-expanding coated esophagus stent was designed to carry radioactive (125)I seeds with different length, diameter and seed spacing. A cylindrical organic glass model (Thickness 0.8 cm, diameter 20 cm, height 20 cm) was fixed vertically to a cylindrical organic glass containing a solid paraffin (analytical pure) solution. After paraffin cooling and solidification, CT scan was used to transmit image information to TPS. With the center of the bracket as a dot, the cumulative dose at a distance of 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 5.0, 6.0 and 8.0 cm away from the dot was simulated respectively in 0° and 9° direction. Results: The radial cumulative dose with the seed spacing which was 1.0 and 1.5 cm were different by 4.8%, 5.8%, 7.2%, 8.0%, 8.6% and 13.3% respectively under the exposure of 18.5, 22.2, 25.9, 29.6, 33.3 and 37.0 MBq. When the seed spacing was the same as the length of the stent, the radial cumulative dose with the stent which diameter was 1.3, 2.0, 2.4 cm were different by 4.9% vs 3.4%, 4.7% vs 3.8%, 5.4% vs 6.6%, 4.5% vs 5.3%, 4.7% vs 4.8%, 4.8% vs 5.4% respectively under the exposure of 18.5, 22.2, 25.9, 29.6, 33.3 and 37.0 MBq. When the seed spacing was the same as the diameter of the stent, the radial cumulative dose with the stent which length was 8, 12, 16 cm were different by 1.9% vs 1.2%, 1.7% vs 0.8%, 1.6% vs 1.3%, 1.9% vs 1.5%, 1.7% vs 1.8%, 1.6% vs 1.3% respectively under the exposure of 18.5, 22.2, 25.9, 29.6, 33.3 and 37.0 MBq. Conclusions: The radial cumulative dose of the (125)I seed stent is positively correlated with the activity of the radioactive seeds, Which means the dose rate of a certain point of the (125)I seed stent increase with the increase of the activity of the radioactive seeds. The stent of the (125)I radioactive seeds is negatively correlated with the distance, the dose rate of the (125)I seed stents decrease rapidly with the increase of distance.

Role and influence of p75NTR receptor on antioxidative damage of retinal pigment epithelial cells

The study aimed to investigate the role and mechanism of the p75 NTR receptor in the oxidative damage of retinal pigment epithelial cells (RPE). RPE cells transfected with the p75 NTR receptor were used as the experimental group, and the untransfected RPE cells as the control group. BrdU (5-Bromo-2-deoxyUridine) was used to detect cell proliferation activity; PI/Annexin V-FITC (fluorescein isothiocyanate, FITC) double staining was used to detect the apoptosis rate of the cells. The expression of reactive oxygen species (ROS) in cells was observed by laser microscope, and the expression of ROS, mitochondrial markers, and C expression of cytochrome in cells was detected by flow cytometry. Western blot was used to detect the Fas protein, pyrolysis Caspase-3, and expression level of the vascular endothelial growth factor 165 (VEGF165) protein. The results showed that the proliferation activity of RPE cells in the experimental group decreased gradually with the increase of transfection time, and the apoptosis rate of RPE cells in the experimental group increased gradually with the increase of transfection time, and the apoptosis rate of RPE cells at each time point was significantly higher than that of the control group. The fluorescence intensity of ROS in the experimental group was significantly stronger than that in the control group (P less than 0.01). The fluorescence intensity of cytochrome C in the RPE cells in the experimental group was significantly higher than that in the control group, while the number of positive mitochondria markers in the experimental group was less than that of the control group and the fluorescence intensity was weakened. The expression of Fas protein, Caspase-3 and VEGF165 protein in the experimental group was significantly higher than that in the control group (P less than 0.01). In conclusion, p75 NTR receptor may be a cause of oxidative damage in RPE cells. .

Precipitating anti-dsDNA peptide repertoires in lupus

Anti-double-stranded (ds)DNA autoantibodies are prototypical serological markers of systemic lupus erythematosus (SLE), but little is known about their immunoglobulin variable (IgV) region composition at the level of the secreted (serum) proteome. Here, we use a novel proteomic workflow based on de novo mass spectrometric sequencing of anti-dsDNA precipitins to analyse IgV subfamily expression and mutational signatures of high-affinity, precipitating anti-dsDNA responses. Serum anti-dsDNA proteomes were oligoclonal with shared (public) expression of immunoglobulin (Ig)G heavy chain variable region (IGHV) and kappa chain variable region (IGKV) subfamilies. IgV peptide maps from eight subjects showed extensive public and random (private) amino acid replacement mutations with prominent arginine substitutions across heavy (H)- and light (L)-chains. Shared sets of L-chain complementarity determining region 3 (CDR3) peptides specified by arginine substitutions were sequenced from the dominantly expressed IGKV3-20 subfamily, with changes in expression levels of a clonal L-chain CDR3 peptide by quantitative multiple reaction monitoring (MRM) paralleling the rise and fall of anti-dsDNA levels by Farr radioimmunoassays (RIA). The heavily mutated IgV peptide signatures of precipitating anti-dsDNA autoantibody proteomes reflect the strong selective forces that shape humoral anti-dsDNA responses in germinal centres. Direct sequencing of agarose gel precipitins using microlitre volumes of stored sera streamlines the antibody sequencing workflow and is generalizable to other precipitating serum antibodies.

[Efficacy and dosimetric analysis of (125)I seeds implantation for pelvic recurrent cervical cancer after radiotherapy under CT guidance]

Objective: To evaluate the relationship of dosimetry parameters and efficacy of (125)I seeds implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy(EBRT) under CT guidance. Methods: A retrospective analysis was made on 30 PRCC patients after EBRT in Peking University Third Hospital with (125)I seeds implantation under CT guidance. Postoperative plans were made to evaluate the dosimetric parameters. Kaplan-Meier method was used to calculate local progression free survival (LPFS) rate and overall survival (OS) rate, and Log-rank test and Cox regression were used for univariate and multivariate analysis. Results: The 1-year and 2-year LPFS rate was 39.4% and 22.5%, respectively. The 1-year and 2-year OS rate was 57.3% and 27.4%, respectively. On postoperative plan, D(90) was (132±47) Gy, D(100) was (51±24) Gy, V(100) was 88%±10%, V(150)was 69%±15%, V(200) was 51%±18%.LPFS time would be longer while D(90) ≥105 Gy or D(100) ≥ 55 Gy or V(100) ≥ 91% (all P<0.05). D(100) was significantly related to LPFS (P<0.05). But these dosimetry parameters got no effect on OS. Conclusions: LPFS time of (125)I seeds implantation for PRCC after EBRT under CT guidance would be longer when D(90)≥105 Gy or D(100)≥ 55 Gy, or V(100)≥ 91%. D(100) is an independent factor related to LPFS.

Handwritten-Digit Recognition by Hybrid Convolutional Neural Network based on HfO2 Memristive Spiking-Neuron

Although there is a huge progress in complementary-metal-oxide-semiconductor (CMOS) technology, construction of an artificial neural network using CMOS technology to realize the functionality comparable with that of human cerebral cortex containing 1010-1011 neurons is still of great challenge. Recently, phase change memristor neuron has been proposed to realize a human-brain level neural network operating at a high speed while consuming a small amount of power and having a high integration density. Although memristor neuron can be scaled down to nanometer, integration of 1010-1011 neurons still faces many problems in circuit complexity, chip area, power consumption, etc. In this work, we propose a CMOS compatible HfO2 memristor neuron that can be well integrated with silicon circuits. A hybrid Convolutional Neural Network (CNN) based on the HfO2 memristor neuron is proposed and constructed. In the hybrid CNN, one memristive neuron can behave as multiple physical neurons based on the Time Division Multiplexing Access (TDMA) technique. Handwritten digit recognition is demonstrated in the hybrid CNN with a memristive neuron acting as 784 physical neurons. This work paves the way towards substantially shrinking the amount of neurons required in hardware and realization of more complex or even human cerebral cortex level memristive neural networks.

Demonstration of a Functionally Active tPA-Like Plasminogen Activator in Human Platelets

The mechanism of platelet-enhanced fibrinolysis is unclear. We therefore investigated the fibrinolytic activity of human platelets and demonstrated that they contain a tissue plasminogen activator (tPA)- like plasminogen activator, abbreviated as tPA-like-PA. This activator was detected by ELISA in platelet incubation medium and in platelet Triton extracts. Plasminogen activation assays showed that this tPA- like-PA could induce plasminogen activation to form plasmin. Western blots of Triton extracts incubated with anti-tPA antibody demonstrated a major 64-kD protein band, compared to a 70-kD band for standard single chain tPA, plus a minor 118-kD band corresponding to a complex of tPA-like-PA and plasminogen activator inhibitor (PAI-1). Western blots of Triton extracts incubated with anti-PAI-1 antibody produced an approximately similar high-molecular-weight (118 kD) protein band. Fibrin zymographic analysis of affinity-purified tPA-like- PA demonstrated a major and a minor fibrin lysis zone, which approximately corresponded to the tPA-like-PA and its complex with PAI-1 observed by Western blots. Immunogold labelling and electron microscopy demonstrated that platelet activator, either as the free form or co-localized with PAI-1, was present in granules and in channels of the open canalicular system. We conclude that platelets contain a functionally active tPA-like-PA, whose low fibrinolytic activity might be due to its readily forming a complex with PAI-1. This functionally active tPA-like-PA might contribute to the enhanced fibrinolytic activity of platelets observed in platelet-rich thrombi.

Isolation, culture, and characterization of chicken lung-derived mesenchymal stem cells

Using lung tissues separated from 12-day-old chicken embryos, we attempted to obtain a novel population of stem cells, namely, chicken lung-derived mesenchymal stem cells (LMSCs), which exhibit spindle-like morphology. The results of colony-forming assay and population doubling assay demonstrated that LMSCs had enormous colony-forming, self-renewal, and proliferative potential. When appropriately induced, LMSCs could differentiate into osteoblasts, adypocytes, chondrocytes, and neurons; in other words, LMSCs had cross-embryonic layer differentiation potential under corresponding induction conditions. Aside from colony-forming, self-renewal, and multilineage differentiation capabilities, LMSCs were characterized by specific cell phenotypes. The results of immunohistochemistry and flow cytometry demonstrated that LMSCs consistently expressed OCT-4 - a specific gene marker expressed in pluripotent stem cells - and markers associated with MSCs such as CD29, CD73, CD90, and CD105. However, LMSCs lacked hematopoietic cell surface molecules such as CD34 and CD45. Primary LMSCs could be subcultured to passage 24 at most in vitro and karyotype analysis demonstrated that LMSCs possessed genomic stability. These unique characteristics were consistent with the characteristics of MSCs, which had been isolated from other tissues. This provides a foundation for LMSCs as a promising avenue for cellular transplantation therapy, regenerative medicine, and tissue engineering.

Optical Properties and Local Structure Evolution during Crystallization of Ga16Sb84 Alloy

Phase-change memory is one of the most promising candidates for future memory technologies. However, most of the phase-change memories are based on chalcogenides, while other families of materials for this purpose remain insufficiently studied. In this work, we investigate the optical properties and microstructure of Ga16Sb84 by an in-situ ellipsometer and X-ray diffraction. Our experimental results reveal that the Ga16Sb84 films exhibit a relatively high crystallization temperature of ~250 °C, excelling in long data retention. In addition, a large optical contrast exists between the amorphous and crystalline states, which may make it suitable for use in optical discs. Molecular dynamics simulations indicate that a unique local structure order in the amorphous and crystalline phases is responsible for the optical properties observed in the experiment. The similarity found in the short-range orders of the amorphous and crystalline phases is beneficial to better understanding the fast phase transition of phase-change memory.

Isolation and biological characteristics of multipotent mesenchymal stromal cells derived from chick embryo intestine

1. Over the past decade, rapid advancement in isolation methods for identifying markers of the once elusive intestinal stem cell (ISC) populations has laid the foundation for unravelling their complex interrelationships during homeostasis. Study on ISC in avian intestinal tissue might play a pivotal foundation for further studies on the epithelial-to-mesenchymal transition (EMT) in gastrointestinal disease and cell-based therapy as well as intestinal tissue engineering. 2. The following experiment isolated a population of fibroblast-like, plastic adhering cells derived from chick embryo intestine, showing a strong self-renewing and proliferative ability, which was maintained in vitro up to passage 25. The findings included growth characteristics, detected expression of cell surface markers and characterised the capability of these cells to differentiate towards the osteogenic, adipogenic, and chondrogenic cell lineages. 3. RT-PCR analysis showed that these cells from chick embryos expressed mesenchymal stromal cell markers CD44, CD90 and VIMENTIN as well as ISC-specific genes LGR5, MI1, SMOC2, BMI1, and HOPX. Immunofluorescence and flow cytometry confirmed this biology characterisation further. 4. In conclusion, cells were isolated from the intestine of 18-day-old chicken embryos that exhibited the biological characteristics of mesenchymal stromal cells as well as markers of intestinal stem cells. Our findings may provide a novel insight for in vitro cell culture and characteristics of ISCs in avian species, which may also indicate a benefit for obtaining cell source for intestinal tissue engineering as well as cell-based investigation for gastrointestinal disease and treatment.

[Research on the reliability and validity of postural workload assessment method and the relation to work-related musculoskeletal disorders of workers]

OBJECTIVE

To form a new assessment method to evaluate postural workload comprehensively analyzing the dynamic and static postural workload for workers during their work process to analyze the reliability and validity, and to study the relation between workers' postural workload and work-related musculoskeletal disorders (WMSDs).

METHODS

In the study, 844 workers from electronic and railway vehicle manufacturing factories were selected as subjects investigated by using the China Musculoskeletal Questionnaire (CMQ) to form the postural workload comprehensive assessment method. The Cronbach's α, cluster analysis and factor analysis were used to assess the reliability and validity of the new assessment method. Non-conditional Logistic regression was used to analyze the relation between workers' postural workload and WMSDs.

RESULTS

Reliability of the assessment method for postural workload: internal consistency analysis results showed that Cronbach's α was 0.934 and the results of split-half reliability indicated that Spearman-Brown coefficient was 0.881 and the correlation coefficient between the first part and the second was 0.787. Validity of the assessment method for postural workload: the results of cluster analysis indicated that square Euclidean distance between dynamic and static postural workload assessment in the same part or work posture was the shortest. The results of factor analysis showed that 2 components were extracted and the cumulative percentage of variance achieved 65.604%. The postural workload score of the different occupational workers showed significant difference (P<0.05) by covariance analysis. The results of nonconditional Logistic regression indicated that alcohol intake (OR=2.141, 95%CI 1.337-3.428) and obesity (OR=3.408, 95%CI 1.629-7.130) were risk factors for WMSDs. The risk for WMSDs would rise as workers' postural workload rose (OR=1.035, 95%CI 1.022-1.048). There was significant different risk for WMSDs in the different groups of workers distinguished by work type, gender and age. Female workers exhibited a higher prevalence for WMSDs (OR=2.626, 95%CI 1.414-4.879) and workers between 30-40 years of age (OR=1.909, 95%CI 1.237-2.946) as compared with those under 30.

CONCLUSION

This method for comprehensively assessing postural workload is reliable and effective when used in assembling workers, and there is certain relation between the postural workload and WMSDs.

Niacin Pretreatment Attenuates Lung Ischemia and Reperfusion-Induced Pulmonary Barrier Function Impairment by Reducing Oxidative Stress and Activating SIRT1 in an Isolated-Perfused Rat Lung Model

PURPOSE

Alveolar-capillary barrier dysfunction, characterized by alveolar protein leak and lung edema, is a common scenario following cardiopulmonary surgery and thoracic organ transplantation. Reactive oxygen species generated through lung ischemia and reperfusion (I/R) injury during surgery plays a crucial role. Niacin, also known as vitamin B3, has been demonstrated to possess antioxidative and anti-inflammatory capacity. In this study, we examine the pulmonary barrier function via capillary filtration coefficient (K_fc) following lung I/R injury with and without niacin treatment.

METHODS

Studies were conducted on male Sprague-Dawley rats in 3 groups: sham-operated, lung I/R injury, and niacin-pretreated lung I/R injury group. Rats were subjected to isolated perfused lung preparation. Lung ischemia was established by continuous perfusion and stopping ventilation for 60 minutes, followed by 60 minutes of ventilation. We assessed the K_fc, lung water content, and protein concentration in the lung lavage; pulmonary oxidative stress and lung inflammation were assessed by leukocyte counts, tissue level of tumor nercrosis factor alpha (TNF-α), and tissue content of malondialdehyde (MDA), respectively. We also assessed the tissue protein level of sirtuin (silent mating type information regulation 2 homolog) 1 (SIRT1).

RESULTS

Lungs subjected to I/R injury significantly increased K_fc, pulmonary oxidative stress, lung water content, and lavage leukocyte count and protein concentration (P < .05). Rats treated with niacin of 100 mg/kg/day for 4 days increased lung SIRT1 (P < .05) and attenuated lung I/R injury-induced pulmonary oxidative stress and inflammation and also improved K_fc.

CONCLUSIONS

Niacin pretreatment protects lungs against I/R injury-induced barrier function impairment through the activation of SIRT1 and reduced pulmonary oxidative stress and lung inflammation.

[Dosimetric analysis of volumetric modulated arc therapy and intensity modulated radiotherapy for patients undergone breast-conserving operation]

OBJECTIVE

To compare the dosimetric differences between volumetric modulated arc therapy and intensity modulated radiotherapy for breast cancer patients after breast-conserving surgery.

METHODS

Ten patients who received radiotherapy after breast-conserving surgery were selected. Eclipse planning system was used to design volumetric rotating intensity-modulated (2F-RapidArc) and two field intensity-modulated radiation therapy (2F-IMRT) planning for each patient. 2F-RapidArc plans were made using two partial arcs with gantry rotation from 287°-293° to 152°-162°, and 0° to 90 ° was avoidance sector. The gantry angle of 2F-IMRT were 301°-311° and 125°-135°. The prescription dose was 46 Gy/23 fractions. All plans required 95% of the target volume receiving the prescription dose. The dose distribution of the target, organs at risk, machine unit (MU) and treatment time were compared.

RESULTS

2F-RapidArc and 2F-IMRT plans' uniformity index was 1.12±0.02 and 1.11±0.03 (P=0.282), respectively; conformal index was 0.80±0.03 and 0.65±0.04 (P<0.001), respectively. V110 of plan target volume was 20.98%±14.47% and 10.43%±10.49% (P=0.030), respectively. Compared with the 2F-IMRT, 2F-RapidArc plans had a higher dosimetric parameters for left lung: V5 (48.06%±17.32% vs. 24.23%±6.56%,P=0.001), V10 (28.89±9.28 vs.17.07±4.78%,P=0.004), Dmean [(9.70±2.14) Gy vs. (6.86±1.77) Gy, P=0.002], increased the double lung: V5 (22.85%±7.55% vs. 11.01%± 2.95%,P=0.001), V10 (13.16%±4.33% vs. 7.76%± 2.16%, P=0.006), Dmean [(4.66±0.95) Gy vs. (3.17±0.82) Gy, P=0.001], reduced the left lung: V40 (3.58%±1.46% vs. 6.19%±3.04%, P=0.006), reduced the double lung: V40 (1.61%±0.64% vs. 2.81%± 1.39%,P=0.005), increased cardiac: V5 (39.3%±17.19% vs. 8.79%±4.24%, P<0.001), V10 (21.31%±13.8% vs. 5.73%±3.42%, P=0.002), V20 (7.80%±6.08% vs. 4.05%±2.85%,P=0.018), Dmean [(0.64±0.25) Gy vs. (0.29±1.39) Gy,P<0.001],reduced the heart: V40(0.50%±0.40% vs. 1.86%±1.94%,P=0.037),increased the contralateral breast Dmean [(1.63±1.26) Gy vs. (0.09±0.05) Gy, P=0.004]. Compared with 2F-IMRTplan, 2F-RapidArc increased the treatment time [(132.9±7.2) s vs. (140.3±11.6) s, P=0.030]. Both the machine units were almost the same [(467.0±30.4) MU vs. (494.7±44.9) MU, P=0.094].

CONCLUSION

Both 2F-RapidArc and 2F-IMRT plans could reach the clinical requirements. 2F-RapidArc had a better conformal index, reduced the high dose area, but increased the low dose regions of the lung, heart, body area, and increased the average dose of the contralateral breast. The treatment time of 2F-RapidArc was longer than that of 2F-IMRT, and the MU of 2F-RapidArc and 2F-IMRT plans were almost the same.

Correlation between luminescence and structural evolution of colloidal silicon nanocrystals synthesized under different laser fluences

We present a detailed investigation of the structural evolution and photoluminescence (PL) properties of colloidal silicon (Si) nanocrystals (NCs) synthesized through femtosecond laser ablation at different laser fluences. It is shown that the mean size of colloidal Si NCs increases from ∼0.97-2.37 nm when increasing laser fluence from 1.0-2.5 mJ cm^-2. On the basis of structural characterization, temperature-dependent PL, time-resolved PL, and PL excitation spectra, we identify that the size-dependent spectral shift of violet emission is attributed to the quantum confinement effect. The localized excitons' radiative recombination via the oxygen-related surface states on the surface of the colloidal Si NCs is employed to explain the origin of the blue emission.

[Effects of non-muscle myosin ⅡA silenced bone marrow mesenchymal stem cells on lung damage of rats at early stage of smoke inhalation injury]

Objective: To investigate the effects of non-muscle myosin ⅡA (NMⅡA) silenced bone marrow mesenchymal stem cells (BMSCs) on the lung damage of rats at early stage of smoke inhalation injury. Methods: Forty Sprague-Dawley rats were divided into control, simple injury, NMⅡA-BMSCs, and BMSCs groups according to the completely random method, with 10 rats in each group. Rats in control group inhaled air normally, while rats in the latter 3 groups inhaled smoke to reproduce model of smoke inhalation injury. At 30 min post injury, rats in simple injury group were injected with 1 mL normal saline via caudal vein, and rats in group BMSCs were injected with 1 mL the fifth passage of BMSCs (1×10(7)/mL), and rats in group NMⅡA-BMSCs were injected with 1 mL NMⅡA silenced BMSCs (1×10(7)/mL). At post injury hour (PIH) 24, abdominal aorta blood and right lung of rats in each group were harvested, and then arterial partial pressure of oxygen (PaO(2)), arterial partial pressure of carbon dioxide (PaCO(2)), and pH value were detected by blood gas analyzer. Ratio of wet to dry weight of lung was determined by dry-wet weight method. Pathological changes of lung were observed with HE staining. Bronchoalveolar lavage fluid (BALF) were collected, and then tumor necrotic factor-α (TNF-α) and interleukin-10 (IL-10) content of BALF was determined by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance, Kruskal-Wallis H test, and least-significant difference test. Results: (1) At PIH 24, compared with those in control group, PaO(2) values of rats in simple injury, BMSCs, and NMⅡA-BMSCs groups were obviously decreased (with P values below 0.05), and PaCO(2) values were obviously increased (with P values below 0.05). Compared with those in simple injury group, PaO(2) values of rats in groups NMⅡA-BMSCs and BMSCs were obviously increased (with P values below 0.05), while PaCO(2) values were obviously decreased (with P values below 0.05). PaO(2) value of rats in group NMⅡA-BMSCs was obviously increased as compared with that in group BMSCs (P<0.05). The pH value of arterial blood of rats in simple injury group was obviously lower than that in control group (P<0.05). (2) At PIH 24, ratios of wet to dry weight of lung of rats in control, simple injury, BMSCs, and NMⅡA-BMSCs groups were 4.36±0.15, 7.79±0.42, 5.77±0.18, and 5.11±0.20, respectively. Compared with that in control group, ratio of wet to dry weight of lung of rats was obviously increased in the other 3 groups (with P values below 0.05). Compared with that in simple injury group, ratio of wet to dry weight of lung of rats was obviously decreased in groups BMSCs and NMⅡA-BMSCs (with P values below 0.05). Compared with that in group BMSCs, ratio of wet to dry weight of lung of rats in group NMⅡA-BMSCs was obviously decreased (P<0.05). (3) At PIH 24, alveolar structure of rats in control group was complete without abnormality. Compared with those in simple injury group, lung injury and infiltration of inflammatory cells of rats in groups BMSCs and NMⅡA-BMSCs were obviously alleviated, and alveolar structure was relatively complete with no thickening of alveolar wall. (4) At PIH 24, compared with that in control group, TNF-α content of BALF of rats in simple injury and BMSCs groups was obviously increased (with P values below 0.05). Compared with that in simple injury group, TNF-α content of BALF in groups BMSCs and NMⅡA-BMSCs was obviously decreased (with P values below 0.05). Compared with that in control group, IL-10 content of BALF in simple injury, NMⅡA-BMSCs and BMSCs groups were obviously increased (with P values below 0.05). Compared with that in simple injury group, IL-10 content of BALF in groups BMSCs and NMⅡA-BMSCs was obviously increased (with P values below 0.05). Compared with that in group BMSCs, IL-10 content of BALF in group NMⅡA-BMSCs was obviously increased (P<0.05). Conclusions: NMⅡA silenced BMSCs can alleviate lung damage of rats at early stage of smoke inhalation injury, showing better effectiveness than using BMSCs only.

Ginsenoside Rg1 protects human renal tubular epithelial cells from lipopolysaccharide-induced apoptosis and inflammation damage

Ginsenoside Rg1, one of the most notable active components of Panax ginseng, has been widely reported to exert anti-inflammatory actions. This study aimed to reveal whether ginsenoside Rg1 also exhibits beneficial roles against lipopolysaccharide (LPS)-induced apoptosis and inflammation in human renal tubular epithelial cells, and to evaluate the potential role of the component on tubulointerstitial nephritis treatment. HK-2 cells were treated with various doses of ginsenoside Rg1 (0, 50, 100, 150, and 200 μM) in the absence or presence of 5 μg/mL LPS. Thereafter, CCK-8 assay, flow cytometry, western blot, migration assay, reactive oxygen species (ROS) assay, and ELISA were carried out to respectively assess cell viability, apoptosis, migration, ROS activity, and the release of inflammatory cytokines. As a result, ginsenoside Rg1 protected HK-2 cells from LPS-induced injury, as cell viability was increased, cell apoptosis was decreased, and the release of MCP-1, IL-1β, IL-6, and TNF-α was reduced. Ginsenoside Rg1 functioned to HK-2 cells in a dose-dependent manner, and the 150 μM dose exhibited the most protective functions. Ginsenoside Rg1 had no significant impact on cell migration and ROS activity, while it alleviated LPS-induced ROS release and migration impairment. Furthermore, the down-regulations of p-PI3K, p-AKT, and up-regulations of PTEN, p-IκBα, p-p65, Bcl-3 induced by LPS were recovered to some extent after ginsenoside Rg1 treatment. In conclusion, ginsenoside Rg1 protects HK-2 cells against LPS-induced inflammation and apoptosis via activation of the PI3K/AKT pathway and suppression of NF-κB pathway.

Comparative study of image contrast in scanning electron microscope and helium ion microscope

Images of Ga⁺ -implanted amorphous silicon layers in a 110 n-type silicon substrate have been collected by a range of detectors in a scanning electron microscope and a helium ion microscope. The effects of the implantation dose and imaging parameters (beam energy, dwell time, etc.) on the image contrast were investigated. We demonstrate a similar relationship for both the helium ion microscope Everhart-Thornley and scanning electron microscope Inlens detectors between the contrast of the images and the Ga⁺ density and imaging parameters. These results also show that dynamic charging effects have a significant impact on the quantification of the helium ion microscope and scanning electron microscope contrast.

Large-scale continuous-variable dual-rail cluster entangled state based on spatial mode comb

In recent continuous-variable (CV) multipartite entanglement researches, the number of fully inseparable light modes has been increased dramatically by the introduction of a multiplexing scheme in either the time domain or the frequency domain. In this paper, we propose a scheme that a large-scale (≥ 20) CV dual-rail cluster entangled state is established based on a spatial mode comb in a self-imaging optical parametric oscillator, which is pumped by two spatial Laguerre-Gaussian modes with different polarization and identical frequency. A sufficient condition of full inseparability for a CV dual-rail cluster entangled state is used to evaluate the degree of quantum entanglement. It is shown that entanglement exists over a wide range of analyzing frequency and pump parameter. We have found a new scheme that uses the optical parametric cavity to generate a large-scale entanglement based on optical spatial mode comb. The presented system will be hopefully as a practical entangled source for quantum information.

[Altered expression and clinical significance of plasma PDGF in patients with myasthnia gravis]

Objective: To evaluate the expression and clinical significance of plasma platelet derived growth factor (PDGF) in the patients with myasthenia gravis (MG). Methods: Plasma samples from 44 MG patients and 34 healthy people were collected from August 2015 to December 2016 from the Second Affiliated Hospital of Harbin Medical University. The expression of PDGF was detected by MILLIPLEX MAP Reagent kit. Furthermore, we analyzed the associations between PDGF expression level and quantitative myasthenia gravis score (QMG). Result: The expression of PDGF in plasma was significant lower in MG patients (5.8±1.3) compared with control group (10.1±2.2), and the difference was statistically significant (t'=-9.767, P<0.001). Meanwhile it was positively related to QMG (r=0.777, P<0.01). However, no significant difference in expression of PDGF in MG subgroups was observed. Conclusion: The expression of PDGF decreases in MG patients, has positive correlation with MG severity, and is not related to age, sex and the pathology of thymus samples.