[A case report of death from toxic encephalopathy caused by emamectin·chlorfenapyr].

Emamectin·chlorfenapyr is insecticide compounded by emamectin benzoate and chlorfenapyr. There is no special antidote after poisoning, and the mortality rate of patients is very high. We admitted a case of toxic encephalopathy caused by oral administration of emamectin·chlorfenapyr. The clinical manifestations of patient were gastrointestinal symptoms, profuse sweating, high fever, changes in consciousness. After admitted to the hospital, despite active comprehensive treatment, the patient died of ineffective rescue eventually.

[Efficacy and safety of levosimendan in elderly patients with severe heart failure].

Objective: To investigate the efficacy and safety of different dosage regimens of levosimendan in elderly patients with severe heart failure. Methods: Thirty-two patients 75 years or older were randomly divided into a loading dose group (16 cases) in which levosimendan was maintained at 0.1 µg·kg(-1)·min(-1) for 24 h after loaded with 6 µg/kg, and a maintenance dose group (16 cases) with same schedule without loading dose. The amino-terminal brain natriuretic peptide (NT-proBNP) before and after treatment was detected. Left ventricular ejection fraction (LVEF), stroke volume (SV), stroke volume index (SVI) by echocardiograph were monitored. Adverse events, the length of stay in ICU and 28-day mortality were recorded. Results: The NT-proBNP level in loading group after treatment was 1 950 (922,6 481)ng/L, which was improved than that before treatment [4 018(2 716,9 637)ng/L, P<0.05]. The result was similar in maintenance group [1 390 (599,3 297)ng/L vs. 4 576 (2 681,10 682)ng/L, P<0.05]. LVEF in loading group before and after treatment was (39.4±8.8) % vs. (48.9±9.2) % respectively, while in maintenance group it was (40.4±8.8) % vs. (48.7±12.0) % (both P<0.05). SV were also improved after treatment in both groups compared with baseline levels (P<0.05). NT-proBNP started to decline on day 3 in the loading group, while on day 7 in the maintenance group. SVI recovered on day 14 in the loading group [ (29.4±6.5) ml/m(2) vs. (27.3±6.7) ml/m(2),P<0.05], while it did not change much in the maintenance group. There was no significant differences as to the length of stay in ICU [ (11.1±4.4) d in loading group vs. (9.6±3.5) d in maintenance group] and 28-day mortality rates were comparable (2/16 in loading group vs. 1/16 in maintenance group) . The adverse events were 7 vs. 2 cases in loading group and maintenance group respectively, which were mild and all alleviated. Conclusion: The application of levosimendan only with maintenance dose improves cardiac function in very elderly patients with severe heart failure. Adverse events are mild and manageable.

[The prognostic role of the programmed death-1 expression on T lymphocytes in septic patients].

Objective: To investigate the value of programmed death-1（PD-1） expression on the T lymphocytes for the prognosis of septic patients. Methods: From September 2017 to May 2019, septic patients were included in Department of Intensive Care Unit at 6 hospitals. The PD-1 expression on T cells were measured by flow cytometry. Logistic regression was conducted to analyze independent risk factors related to death within 28 days，and receiver operating characteristic curve(ROC) was conducted to evaluate the prognostic value of PD-1 expression on T cells in septic patients. Results: A total of 64 septic patients were enrolled to this study，including 32 survivors and 32 deaths. The PD-1 expression on T cells in the death group was significantly higher than that in the surviving group (P<0.05). Correlation analysis showed that the percentages of PD-1+/CD3+T cells and PD-1+/CD8+T cells were positively correlated with procalciton in (r=0.313, P =0.015；r=0.375, P=0.003), logistic regression analysis showed that the percentages of PD-1+/CD3+，PD-1+/CD4+，PD-1+/CD8+T cells were independent risk factors for the death of sepsis patients. The percentage of PD-1+/CD3+T cell was 3.63%, with AUC 0.842, sensitivity to predict the mortality 96.43% and specificity 59.38%, (P<0.000 1). The percentage of PD-1+/CD4+T cell was 4.65%, with AUC 0.847, sensitivity 96.43%, specificity 62.50%，(P<0.000 1). The percentage of PD-1+/CD8+T cell was 3.91%, with AUC 0.771, sensitivity 64.29%, specificity 81.25%，(P=0.000 3). Conclusions: The T cell PD-1 expression is an independent risk factor to predict the 28-day mortality in septic patients. Combining the proportions of PD-1+/CD3+, PD-1+/CD4+and PD-1+/CD8+T cells may further enhance the predictive value for death.

[The effects of levosimendan on the cardiac function and prognosis in elderly patients with septic shock and myocardial contractility impairment].

Objective: To investigate the effect of levosimendan on cardiac function and prognosis in elderly patients with septic myocardial contractility impairment. Methods: A prospective, randomized, controlled study was conducted. The elderly patients with septic myocardial contractility impairment who were admitted to Intensive Care Unit in Zhejiang Hospital were consecutively enrolled from January 2017 to September 2017. The key inclusive criterion was left ventricular ejection fraction (LVEF) ≤50% after fluid resuscitation. A total of 30 patients were randomly assigned to levosimendan group (n=15) and dobutamine group (n=15). Based onconventional treatment, intravenous dobutamine (5 µg per kilogram of body weight per minute) or levosimendan (0.2 µg per kilogram of body weight per minute)were continuously administrated for 24 hours in two groups. At 0 h,24 h,48 h, 72 h after injection, the following parameters or values were recorded including serum lactic acid (Lac), and echocardiographic parameters such as LVEF, stroke volume (SV). The time of mechanical ventilation, length of stay in ICU and 28-day mortality were compared in two groups. Results: Compared with dobutamine group, blood Lac at 24 h [(1.97±1.10)mmol/L vs. (2.73±2.06) mmol/L, P=0.002] decreased significantlyin levosimendan group. LVEF and SV were significantly higher in levosimendan group at 24 h [LVEF:(47.93±5.01)% vs.(45.60±5.47)%, P=0.004;SV:(47.73±14.01) ml vs. (44.80±16.89) ml, P=0.035;respectively], 48 h [LVEF:(51.07±5.05)% vs.(46.73±6.34)%, P=0.004;SV: (49.87±14.15) ml vs. (45.07±16.94) ml, P=0.005;respectively] and 72 h [LVEF:(53.20±5.92)% vs. (47.70±6.71)%, P=0.002;SV:(51.27±14.98) ml vs. (45.73±17.34) ml, P=0.010]. The time of mechanical ventilation, length of stay in ICU and 28-day mortality were comparable between two groups (P>0.05). Conclusions: Levosimendan improves cardiac systolic function and tissue perfusion in elderly patients with septic myocardial contractility impairment. However, cardiac diastolic function, liver and kidney function are not further improved by levosimendan compare with dubutamine. Time of mechanical ventilation, length of stay in ICU and 28-day mortality in two groups are similar.

[Correlation of transcutaneous oxygen pressure and blood lactate in patients with septic shock].

To analyze the correlation between transcutaneous oxygen pressure (P(tc)O(2)) and blood lactate in patients with septic shock. Fifty-sixpatients with septic shock were prospectively investigated. P(tc)O(2) was monitored continuously for 6 hours, and arterial blood gas was measured at baseline (T0) and 6 hours(T6). Records of P(tc)O(2),were analyzed for the correlation with lactate level and lactate clearance rate. P(tc)O(2) valuesin the high lactate clearance group and the low one were compared.The lowest value of P(tc)O(2) at T6 and duration of P(tc)O(2)<40 mmHg (1 mmHg=0.133 kPa) were both correlated with lactate level and lactate clearance rateat T6.The low predictive value of P(tc)O(2) was 29 mmHg of lactate clearance under 20% with a sensitivity 85.2% and a specificity 65.5%. The low predictive value of P(tc)O(2) in high lactate clearance group was significantly higher than that in low lactate clearance group, while the duration of P(tc)O(2)<40 mmHg was shorter than the latter. During 6 h continuous monitoring, patients with a significant low P(tc)O(2) or prolonged duration of low P(tc)O(2) have relatively high lactate or low lactate clearance after resuscitation.

[The influence of left ventricular-arterial coupling on the prognosis of elderly patients with septic shock].

OBJECTIVE: To investigate the influence of left ventricular-arterial coupling(VAC) on clinical prognosis of elderly patients with septic shock. METHODS: A total of 56 elderly septic shock patients were enrolled in this study, all of whom were admitted to Department of Intensive Care Unit in Zhejiang Hospital from August 2014 to October 2015.The patients were divided into two groups according to the status of left ventricular-arterial coupling when septic shock was diagnosed, which were left ventricular-arterial uncoupling group(UC group) and left ventricular-arterial coupling group(C group). Various parameters were recorded, including blood lactate level, central venous oxygen saturation(ScvO2), serum level of N-terminal pro-brain natriuretic peptide(NT-proBNP) and cardiac troponin Ⅰ(cTNⅠ), dose of vasoactive drugs, the total fluid volume and urine volume per hour within 24 hours. The 28-day survival rate was a key index of prognosis. Multivariate logistic regression was taken to analyze risk factors related to death within 28 day. RESULTS: Compared with C group, UC group had lower values of left ventricular ejection fraction[(42.43±4.76)% vs (53.17±3.01)%; P<0.01] and cardiac index[(2.36±0.68) L·min(-1)·m(-2) vs (2.93±0.45)L·min(-1)·m(-2); P<0.01]. Yet serum levels of NT-proBNP[lg NT-proBNP 3.93±0.53 vs 3.40±0.63; P=0.004] and cTNⅠ [lg cTNⅠ-0.16±0.68 vs-1.03±0.69; P<0.001] in UC group were higher than those in C group. Moreover, the total fluid volume within 24 hours [(3 806.3±831.4) ml vs (3 142.0±770.0) ml; P=0.016], blood lactate level[(5.61±2.68) mmol/L vs (3.93±1.59) mmol/L; P=0.043] and dose of norepinephrine[(0.630±0.300)µg·kg(-1)·min(-1) vs (0.292±0.234)µg·kg(-1)·min(-1;) P=0.001] in UC group were greater than those in C group, while ScvO2[(60.75±2.91)% vs (64.42±2.19)%; P<0.001] and urine volume per hour[(0.518±0.358)ml vs (0.926±0.678)ml; P=0.007] were less than those in C group. Compared with C group, UC group had a lower 28-day survival rate[43.2%(19/44) vs 9/12; P=0.049]. Ea/Ees ratio was negatively correlated with LVEF, ScvO2(r=-0.686, P<0.001; r=-0.411, P=0.002), positively correlated with NT-proBNP, cTNⅠ(r=0.294, P=0.028; r=0.363, P=0.006), yet no obvious correlation was noticed with blood lactate level(r=0.170, P=0.21). Multiple logistic regression analysis showed that VAC(OR=11.187, 95%CI 2.489-50.285; P=0.002), lactate level (OR=1.727, 95%CI 1.164-2.563; P=0.007) and lg cTNⅠ(OR=0.247, 95%CI 0.079-0.779; P=0.017) were independent risk factors affecting 28-day mortality. Conclutions: In elderly patients with septic shock, left ventricular-arterial uncoupling indicates a lower 28-day survival rate, worse cardiac function and tissue perfusion. Ea/Ees ratio might sever as a predictive indicator of 28-day mortality.

[Venous-to-arterial carbon dioxide difference to arteriovenous oxygen content difference ratio combined with lactate to predict prognosis of patients with septic shock].

OBJECTIVE: To investigate the prognostic significance of venous-to-arterial carbon dioxide difference to arteriovenous oxygen content difference ratio (Pv-aCO2/Ca-vO2 ratio) combined with lactate in patients with septic shock during the early phases of resuscitation. METHODS: A retrospective study was conducted for 104 septic shock patients. All patients received an initial fluid resuscitation according to the Surviving Sepsis Campaign: International Guidelines for Management of Severe Sepsis and Septic Shock, 2012(SSC2012). Patients were classified into four groups according to lactate levels and Pv-aCO2/Ca-vO2 ratio at 6 h of resuscitation: group A, lactate≥2.0 mmol/L and Pv-aCO2/Ca-vO2>1.0; group B, lactate≥2.0 mmol/L and Pv-aCO2/Ca-vO2≤1.0; group C, lactate<2.0 mmol/L and Pv-aCO2/Ca-vO2>1.0; group D, lactate<2.0 mmol/L and Pv-aCO2/Ca-vO2≤1.0. The hemodynamic parameters and oxygen metabolism parameters were recorded at baseline and 6 h after fluid resuscitation. Sequential organ failure assessment (SOFA) score at day 1, day 3 were calculated. The 28-day mortality rate was recorded. RESULTS: (1) Group A had the highest SOFA score at day 3 and group D the lowest, which were respectively 10.8±3.3, 6.7±3.6, 5.6±3.1, 4.1±2.2 in four groups. Accordingly, the 28-day mortality rate of group A was the highest and group D the lowest, which were respectively 83.3%, 59.1%, 60.0%, 14.3% in four groups. The differences were statistically significant (P<0.05). (2) The Cox regression analysis of 28 d mortality revealed that lactate levels (RR=4.306, 95%CI 1.979-9.369) and Pv-aCO2/Ca-vO2 ratio (RR=2.888, 95%CI 1.676-4.976) at T6 were independent predictors to 28-day mortality. (3) The AUCROC of Pv-aCO2/Ca-vO2 ratio combined with lactate [0.910(95%CI 0.857-0.963)] was significantly greater than the AUCROC of wither lactate [0.762(95%CI 0.673-0.852), Z=2.775; P=0.006) or Pv-aCO2/Ca-vO2 ratio [0.781(95%CI 0.693-0.868), Z=2.458; P=0.014) alone. CONCLUSION: Combination of Pv-aCO2/Ca-vO2 ratio and lactate level at early stage of resuscitation in patients with septic shock is better than single parameter to predict the prognosis.

Relationship between nicotinic receptors and cognitive function in early Alzheimer's disease: a 2-[18F]fluoro-A-85380 PET study.

Neuronal nicotinic acetylcholine receptors (nAChRs) are critical for higher order cognitive processes. Post-mortem studies suggest reductions in nAChRs (particularly the alpha(4)beta(2) subtype) with ageing and in Alzheimer's disease (AD). This study aimed to; (1) quantify nAChR distribution in vivo with 2-[18F]fluoro-A-85380 (2-FA) in 15 early AD patients compared to 14 age-matched, healthy controls (HC) and (2) correlate nAChR distribution with cognitive performance in both groups. All participants were non-smokers and underwent cognitive testing along with a dynamic PET scan after injection of 200 MBq of 2-FA. Brain regional 2-FA binding was assessed through a simplified estimation of Distribution Volume (DV(S)). The AD group differed significantly from HC on all cognitive measures employed, with impairments on measures of attention, working memory, language, executive function, visuospatial ability, verbal learning and verbal memory (p<.05). Contrary to post-mortem data this study found no evidence of in vivo nAChR loss in early AD despite significant cognitive impairment. Furthermore, no correlation between nAChR and cognitive performance was found for either group. The findings of the current study suggest preservation of nAChRs early in AD supporting previous studies. It is possible that while the clinical 2-FA PET method described here may be insensitive in detecting changes in early AD, such changes may be detected in more advanced stages of the illness.

Exploring structural phase transitions of ion crystals.

Phase transitions have been a research focus in many-body physics over past decades. Cold ions, under strong Coulomb repulsion, provide a repealing paradigm of exploring phase transitions in stable confinement by electromagnetic field. We demonstrate various conformations of up to sixteen laser-cooled (40)Ca(+) ion crystals in a home-built surface-electrode trap, where besides the usually mentioned structural phase transition from the linear to the zigzag, two additional phase transitions to more complicated two-dimensional configurations are identified. The experimental observation agrees well with the numerical simulation. Heating due to micromotion of the ions is analysed by comparison of the numerical simulation with the experimental observation. Our investigation implies very rich and complicated many-body behaviour in the trapped-ion systems and provides effective mechanism for further exploring quantum phase transitions and quantum information processing with ultracold trapped ions.

Correlation of tissue and blood plasminogen activation system in breast cancer.

The plasminogen activation system plays a crucial role during cancer invasion and metastasis. In the solid tumor, urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor type-1 (PAI-1) and uPA receptor (uPAR) are considered as prognostic factors. In this study, we have investigated whether secretion of the uPA, PAI-1 and uPAR from the primary breast cancer tissue can be detected in the blood of the patients using the ELISA assay. We have found that the plasminogen activation system (uPA, PAI-1, uPAR) of tumor tissue is activated from the early stage of breast cancer. However, only a number of metastatic lymph nodes was a prognostic factor in multivariate analysis for relapse. The blood level of the plasminogen activation system correlated with that of tissue in an order of uPAR (r(2)=0.61; P=0.001), uPA (r(2)=0.35; P=0.001) and PAI-1 (r(2)=0.11; P=0.001). We conclude that the total uPAR level of cancer tissue can be substituted by that which is detected in the blood for further clinical applications.

Effects of interleukin-2 transduction on the human hepatoma cell lines using retroviral vector.

Gene therapy, using cytokine gene transduction, aims to increase the antigenicity of tumor cells, and to activate the immune effector cells, and thereby inducing tumor regression. With regards to in vitro sensitivity to peripheral blood monocytes and in vivo tumorigenic activity we compared the differences between parent hepatoma cell lines and interleukin-2 (IL-2) transduced hepatoma cell lines using N2A/IL-2 and LNC/IL-2 retrovirus. IL-2 secretion was 186 pg/10(6) cells/24 h in SK-Hep1 cell line and 147 pg/106 cells/24 h in Hep-3B cell line with N2A/IL-2 retroviral vector and was 55,000 pg/10(6) cells/24 h in Hep-3B cell line with LNC/IL-2 retroviral vector. in vitro sensitivity to peripheral blood monocytes was increased by 163.8-254% in IL-2 transduced hepatoma cell lines (Hep-3B/LNC/IL-2, Hep-G2/LNC/IL-2) compared to those of the parent cell lines. The tumor was formed in 1 of 3 BALB/c mice and all 3 nude mice with the injection of 1x107 cells. Simultaneous injection of 1x10(7) cells of the parent cell line (Hep-3B) into the right flank and IL-2 transduced cell line (Hep-3B/LNC/IL-2) into the left flank of the three BALB/c mice and of 5x10(5) cells for the three nude mice resulted in a complete regression of the IL-2 modified tumor cell line (Hep-3B/LNC/IL-2) in 3 weeks and the parent cell line (Hep-3B) in 5 weeks. After injection of 1x10(7) cells into five other nude mice, the tumor of the IL-2 transduced hepatoma cells (Hep-3B/LNC/IL-2) gradually disappeared, however, the tumor of the parent hepatoma cell line initially decreased and then gradually regrew 20 days later. In conclusion, IL-2 transduced hepatoma cell lines secreting IL-2 became more sensitive to peripheral blood monocytes. IL-2 secretion by LNC/IL-2 retrovirus from the hepatoma cell lines was more prominent compared with that by N2A/IL-2 retrovirus. IL-2 transduction into the hepatoma cells resulted in increased antigenicity to the tumors formed by IL-2 transduced hepatoma cell line and parent cell line, which leads the regression of the tumors. However, the higher the tumor burden, the less efficient tumor regression by IL-2 transduction into the hepatoma cell line in nude mice was observed.

Combined pre-operative chemotherapy with intra-arterial cisplatin and continuous intravenous adriamycin for high grade osteosarcoma.

Osteosarcoma is one of the most common juvenile malignant tumors in Korea. Combined modality treatment (pre-operative chemotherapy + limb salvage surgery + adjuvant therapy) improved the patients' overall survival and quality of life. We evaluated the efficacy and feasibility of pre-operative chemotherapy with intra-arterial (IA) cisplatin plus continuous intravenous infusion (CI) of adriamycin. We assessed the rate of limb salvage, recurrence pattern and the survival impact based on the histologic response of pre-operative chemotherapy. Fourty-one patients with histologically-proven high grade osteosarcoma of the extremities were enrolled from January 1990 to June 1995. Pre-operative chemotherapy, cisplatin 120 mg/m2 IA and adriamycin 75 mg/m2/72 h CI was administered every 3 weeks for 3 cycles, followed by limb salvage surgery if possible or by amputation. According to the histologic tumor response, if the tumor necrosis was >90%, the same regimen was administered for 3 cycles as an adjuvant therapy. A salvage regimen (Ifosfamide 7.5 gm/m2/5 d IV + high dose MTX 10 gm/m2 IV+VP-16 360 mg/m2/3 d IV) was administered every 3 weeks for 6 cycles if the tumor necrosis was <90%. Of 41 patients, 37 patients were evaluable for efficacy and toxicities, because 4 patients refused chemotherapy after 1 or 2 cycles. Twenty-one patients were male and 16 were female with median age of 16 years (range 8-41). The tumor locations were: distal femur 20, proximal tibia 8, humerus 6, distal tibia 2 and 1 in proximal femur. All but one patient, who died of neutropenic sepsis, completed the planned pre-operative therapy. Of the 36 patients who received surgery, limb salvage surgery was possible in 30 patients (83.3%) and 27 patients (75%) showed a good response (grade III 10; 27.8%, grade IV 17; 47.2%). With a median follow-up of 23 months, 3-year disease-free survival rate was 54.7% and overall survival rate was 78.3%. Of the 15 patients who recurred, the major metastatic site was the lung. No operation-related mortality was observed. Most patients experienced grade III-IV nausea, vomiting and hematologic toxicities, which were reversible with supportive cares. Pre-operative chemotherapy with IA DDP+CI ADR followed by surgery showed 75% histologic tumor response rate, 83% limb salvage rate and 54.7% 3-year disease-free survival rate with tolerable side effects. To improve the survival rate, the possible role of good salvage chemotherapy with a non-cross resistance regimen in poor responders should be evaluated.

Tissue urokinase-type plasminogen activator receptor levels in breast cancer.

Cancer invasion is induced by several proteolytic enzyme systems associated with the destruction of basement membrane and extracellular matrix. Urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) have been reported as prognostic factors in breast cancer patients and plasminogen activation is regulated by various factors such as uPAR and growth factors. Thus, we examined the tissue levels of urokinase-type plasminogen activator receptor (uPAR) in breast cancer patients. Tissue uPAR levels were measured by ELISA assay in 268 breast cancer patients. The median and mean values of tissue uPAR level in breast cancer were 3.5 ng/mg cytosol protein and 4.8+/-3.6 ng/mg cytosol protein, respectively. Tissue uPAR level was the highest in T1 stage, but there was no statistical significance between the T stages (p>0.05), nor in nodal stage, in the value of uPAR according to progression. And the value of uPAR expression was not associated with estrogen and progesterone receptor status, number of involved node and percent of node involvement. In TNM stage, tissue uPAR levels were higher in patients with stage I-II than in patients with stage III-IV (p=0.027). In univariate analysis, nodal factor (p=0.002) and TNM stage (p=0.0004) were significant. But, multivariate analysis showed that TNM stage was the only significant prognostic factor (p=0.0002). These results suggest that uPAR is mainly associated with initial tumor invasion and other factors might be involved in later stages of cancer progression.

P-glycoprotein as an intermediate end point of drug resistance to neoadjuvant chemotherapy in locally advanced gastric cancer.

The expression of p-glycoprotein (p-gp) was evaluated in pre- and post-chemotherapy states after the administration of adriamycin-based chemotherapy in 24 gastric cancer patients. Among them, group A was composed of twelve patients who relapsed after surgery plus adjuvant chemotherapy and group B was composed of another twelve patients who received neoadjuvant chemotherapy plus surgery. Pre-chemotherapy p-gp was evaluated in 18 out of 24 patients (6 patients had no pre-chemotherapy paraffin blocks) and post-chemotherapy p-gp was evaluated from all 24 patients. Pre- and post-chemotherapy p-gp was expressed in 5 of 18 patients (27.8%), and 9 of 24 patients (37.5%), respectively, with immunohistochemical stain using monoclonal antibody JSB-1. No differences of disease-free survivals were observed in Group A based on post-chemotherapy p-gp expression from relapsed lesions. In Group B, there was a higher relapse rate (p = 0.04) and a lower one-year disease-free survival rate (p = 0.04) in post-chemotherapy p-gp positive patients when adjuvant treatment was done with the same regimen as neoadjuvant chemotherapy. In all patients studied, post-chemotherapy p-gp expression correlated with a higher systemic recurrence (p = 0.04). These data suggest that p-gp can be induced by an adriamycin-based chemotherapy in gastric cancer. Thus, we suggest that the prognosis of gastric cancer may be poor if a multidrug resistance (MDR)-related regimen is used in the presence of p-gp after neoadjuvant chemotherapy with an adriamycin-based regimen, even if the initial response is good.

Picosecond electric field pulse induced coherent magnetic switching in MgO/FePt/Pt(001)-based tunnel junctions: a multiscale study.

Combined methods of first-principles calculations and Landau-Lifshitz-Gilbert (LLG) macrospin simulations are performed to investigate the coherent magnetization switching in the MgO/FePt/Pt(001)-based magnetic tunnel junctions triggered by short pulses of electric field through the control of magnetic anisotropy energy (MAE) electrically. First-principles calculations indicate that the MAE of MgO/FePt/Pt(001) film varies linearly with the change of the electric field, whereas the LLG simulations show that the change in MAE by electric field pulses could induce the in-plane magnetization reversal of the free layer by tuning the pulse parameters. We find that there exist a critical pulse width τmin to switch the in-plane magnetization, and this τmin deceases with the increasing pulse amplitude E0. Besides, the magnetization orientation cannot be switched when the pulse width exceeds a critical value τmax, and τmax increases asymptotically with E0. In addition, there exist some irregular switching areas at short pulse width due to the high precessional frequency under small initial angle. Finally, a successive magnetization switching can be achieved by a series of electric field pulses.

First-principles investigation of bilayer graphene with intercalated C, N or O atoms.

We apply first-principles calculations to investigate the structural, electronic and magnetic properties of the bilayer graphene, into which C, N or O atoms are intercalated. The inserted atoms initially set at the middle of the bilayer interval will finally be adsorbed to one graphene layer, resulting in the difference of electrostatic potential between the two graphene layers and then an opening of the energy gap filled with impurity states. Extended or quasilocalized states around the Fermi level introduced by the intercalated atoms induce the itinerant Stoner magnetism in C- and N-intercalated systems. The magnetic moment in the N-intercalated system is mainly contributed by the N atom, while in the C-intercalated system, besides the foreign intercalated C atom, host carbon atoms of the bilayer graphene also become magnetic, with the magnetization distribution showing threefold symmetry. Also, charge transfer from bilayer graphene to the intercalated N or O atoms results in the Fermi level shifting downward to the valence band and then the metallic behavior of the system.