Ultra-high resistive switching current ratio and improved ferroelectricity and dielectric tunability performance in a BaTiO3/La0.7Sr0.3MnO3 heterostructure by inserting a SrCoO2.5 layer.

A BaTiO3/SrCoO2.5 (BTO/SCO) bilayer and a BTO single film were prepared by radio frequency magnetron sputtering on La0.7Sr0.3MnO3 (LSMO) buffered SrTiO3 (001) substrates. Interestingly, compared with reported BTO-based films, the BTO/SCO/LSMO heterostructure has a maximum ON/OFF current ratio of ∼945. More interestingly, compared with the BTO single layer, a larger Pr (∼18.4 µC cm-2) and larger dielectric tunability (∼71.9%) were achieved in the BTO/SCO bilayer. The improved performance may be attributed to the large tetragonality and improved oxygen vacancy concentrations in the BTO/SCO/LSMO heterostructure. Furthermore, our BTO/SCO/LSMO stacks exhibit potential for flexible electronic informational devices.

[Early changes within the lymphocyte population are associated with the long term prognosis in severely injured patients].

OBJECTIVE: To investigate the relationship between early lymphocyte responses and the prognosis in severely injured patients. METHODS: Consecutive patients with severe trauma who were treated in Peking University People's Hospital Trauma Medical Center between June 2017 and June 2020 were enrolled in this restropective chart-review study. According to the responses of lymphocyte after severe injury, the patients were divided into three groups, group 1: lymphopenia-returned to normal; group 2: persistent lymphopenia; group 3: never lymphopenic, and the outcome of 28 d were recorded. Clinical data such as gender, age, base excess, mechanism of injury, Glasgow coma scale (GCS), injury severity score (ISS) and massive blood transfusion were collected. Perform statistical analysis on the collected clinical data to understand the trend of lymphocyte changes in early trauma and the relationship with prognosis. In order to eliminate the interference of age, stratification was carried out according to whether the age was ≥ 65 years old, in different age groups, they were grouped according to whether the length of stay was ≥ 28 d, and the relationship between lymphocyte trend and length of stay was discussed. RESULTS: A total of 83 patients were included, 66 males and 17 females. The main injury mechanisms were traffic accident injuries and high-altitude fall injuries. The average ISS was (30±11) points. 65 patients had lymphopenia on the day of injury, 32 of them returned to normal on the 5th day, and the rest did not recover; the other 18 patients had normal lymphocyte levels after injury. Patients which are failure to normalize lymphopenia within the first 5 days following admission was related with the long hospitalization time and higher 28 d mortality rate. After further stratification by age, failure to normalize lymphopenia within the first 5 days following admission in the elderly group (age ≥65 years) was a risk factor for prolonged hospital stay (≥28 d), P=0.04. While in younger group, a high level of neutrophils within the first 5 d following admission was a risk factor for bad outcome. CONCLUSION: A failure to normalize lymphopenia in severely injured patients is associated with significantly higher mortality and longer hospital stay. This study reveals lymphocytes can be used as a reliable indicator for the prognostic evaluation.

[Risk factors for mechanical ventilation in patients with severe multiple trauma].

OBJECTIVE: To eludicate the risk factors of mechanical ventilation and prolonged mechanical ventilation in patients with severe multiple injuries. METHODS: Consecutive patients with severe multiple injures who were treated in Peking University People's Hospital Trauma Medical Center between December 2016 and December 2019 were enrolled in this restropective chart-review study. According to mechanical ventilation and ventilatory time, the patients were divided into mechanical ventilation (MV) group and non-mechanical ventilation (NMV) groups, prolonged mechanical ventilation (PMV) group and shortened mechanical ventilation (SMV) groups. Clinical data such as gender, age, base excess, mechanism of injury, Glasgow Coma Scale (GCS), abbreviated injury scale (AIS) and injury severity score (ISS) were collected. To indentify the risk factors of mechanical ventilation and prolonged mecha-nical ventilation, univariate and multivariate Logistic analyses were carried out. RESULTS: In the present study, 112 patients (82 male, 30 female) with severe multiple injuries having a median age of 52 (range: 16-89 years) and a median ISS of 34 (range: 16-66) were enrolled. The primary mechanism of injury was traffic accident injury and falling injury. In the study, 62 and 50 patients were assigned to MV and NMV groups, respectively. Logistic analysis showed that GCS (OR=0.72, 95%CI: 0.53-0.92, P=0.03), base excess (OR=0.56, 95%CI: 0.37-0.88, P=0.002) and multiple rib fracture (OR=1.72, 95%CI: 1.60-2.80, P=0.012) were independent significant risk factors for mechanical ventilation after severe multiple injuries. Within the mechanical ventilation group, 38 and 24 patients were assigned to PMV and SMVgroups, respectively. Compared with the SMV group, the PMV group had a higher ISS and higher rate of severe head trauma. The length of hospital stay of PMV group was longer than that of SMV groups. Meanwhile, the incidence of tracheotomy in PMV group was high. CONCLUSIONS: GCS, base excess and rib fracture might be independent risk factors for mechanical ventilation. Higher ISS and lower GCS might prolong the ventilatory time and the length of hospital stay. Meanwhile, the incidence of tracheotomy was high in PMV group because of the longer ventilatory time and poor consciousness.

[Development and chinization of diagnostic criteria for oral lichen planus].

Oral lichen planus (OLP) is a common chronic inflammatory disease of oral mucosa. The diagnostic criteria of OLP is the cornerstone of clinical diagnosis and treatment and scientific research. However, there are various understandings of the diagnostic criteria in China. Thus several questions need to be answered, for example, how to combine the international diagnostic criteria with China's specific conditions, how to apply the criteria into clinical practice, and how to use the criteria guiding clinical work and scientific research in China. The authors of this article systematically introduced and discussed the development, content and difference of the international diagnostic criteria of OLP. We proposed "23 Princeples" for the selection of biopsy indications in OLP diagnosis based on authors' personal experiences in clinical and basic research and the actual conditions of Chinese clinicians. We also express our own views and suggestions about some other hot issues associated with OLP diagnosis.

Direct Detection of Pure ac Spin Current by X-Ray Pump-Probe Measurements.

Despite recent progress in spin-current research, the detection of spin current has mostly remained indirect. By synchronizing a microwave waveform with synchrotron x-ray pulses, we use the ferromagnetic resonance of the Py (Ni_{81}Fe_{19}) layer in a Py/Cu/Cu_{75}Mn_{25}/Cu/Co multilayer to pump a pure ac spin current into the Cu_{75}Mn_{25} and Co layers, and then directly probe the spin current within the Cu_{75}Mn_{25} layer and the spin dynamics of the Co layer by x-ray magnetic circular dichroism. This element-resolved pump-probe measurement unambiguously identifies the ac spin current in the Cu_{75}Mn_{25} layer.

Tailoring the magnetic anisotropy of Py/Ni bilayer films using well aligned atomic steps on Cu(001).

Tailoring the spin orientation at the atomic scale has been a key task in spintronics technology. While controlling the out-of-plane to in-plane spin orientation has been achieved by a precise control of the perpendicular magnetic anisotropy at atomic layer thickness level, a design and control of the in-plane magnetic anisotropy has not yet been well developed. On well aligned atomic steps of a 6° vicinal Cu(001) surface with steps parallel to the [110] axis, we grow Py/Ni overlayer films epitaxially to permit a systematic exploration of the step-induced in-plane magnetic anisotropy as a function of both the Py and the Ni film thicknesses. We found that the atomic steps from the vicinal Cu(001) induce an in-plane uniaxial magnetic anisotropy that favors both Py and Ni magnetizations perpendicular to the steps, opposite to the behavior of Co on vicinal Cu(001). In addition, thickness-dependent study shows that the Ni films exhibit different magnetic anisotropy below and above ~6 ML Ni thickness.

[Bovine alpha-sl-casein gene sequences direct expression of a variant of human tissue plasminogen activator in the milk of transgenic mice].

The fusion gene containing the promoter of casein gene, LAtPA minigene and 3' flanking sequences of casein gene was introduced into the fertilized eggs of mice by microinjection. Five positive transgenic mice were obtained. The concentration of LAtPA in the milk of one female transgenic mouse is 0.18 microgram/ml. This result showed that the LAtPA minigene could correctly express the bioactive LAtPA in the milk of the transgenic mouse under the control of the regulatory elements of the casein gene.

[The expression of tPA directed by the bovine BLG regulatory elements in the mammary gland of transgenic mice].

In order to get the regulatory elements which are essential for generating mammary gland bioreactors, the whole 8.4 kb bovine BLG gene was obtained by PCR amplification. The 1.6 kb chicken lysozyme matrix attachment region (MAR) was used to overcome position effects. The bovine BLG-tPA expression vector was constructed and the BLG-tPA fusion gene was introduced into fertilized eggs of mice by microinjection to generate transgenic mouse. 170 offsprings were obtained, of which 9 were proved to be transgenic mice based on PCR and Southern-blot analysis. The tPA expression level amounted to 12 micrograms/mL in the milk of mice. The bovine BLG-tPA fusion gene integrated in the founders was inheritable.

[Co-integration of BLG-LAtPA and WAP improved the expression of LAtPA in transgenic mouse milk].

In order to improve the expression of longer acting tissue plasminogen activator in the mammary epithelium of transgenic mice, the fragment of BLG-LAtPA hydrid gene was microinjected into mouse embryos with mice whey acid protein gene. Three mouse were tested as being Co-integration of BLG-LAtPA and WAP transgene by PCR and Southern blot. Milk obtained from lactating females contains biologically active tPA, and the concentration of tPA was calculated to be about 10 micrograms/mL.

[Cloning cDNA of extracellular domain of human erythropoietin receptor and its expression in Escherichia coli].

Human erythropoietin receptor (hEpoR) plays an important role in regulating the red blood cell production by promoting the proliferation and differentiation of RBC from erythroid precursors. hEpoR is a transmembrane protein, and its extrocellular domain (sEpoR) is of great importance in Epo signal transduction pathway. We cloned the gene of sEpoR by RT-PCR from the total RNA of human fetal liver and expressed it in E. coli after insertion of the gene in the expression vector pBV220. The cloned gene was confirmed by sequencing analysis and gene product was confirmed by both Western blot and its first 11 amino acid residues sequence of the N-terminal. In vitro bioassay showed that the purified gene product can repress the growth of TF-cells in the presence of Epo.

[Cloning of human G-CSF genomic gene and its expression in transgenic mice mammary gland].

Human genomic DNA was used as template of PCR. 1.5 kb G-CSF genomic DNA was obtained using PCR amplification method. Sequence analysis showed that genomic DNA sequence of human G-CSF was correct. The vector of mammary gland expression was constructed and contained whey acid protein (WAP) 5' control region directed human G-CSF genomic DNA. In order to produce transgenic mice, 1200 fertilized eggs were microninjected using WAP-G-CSF fragment. Two male transgenic mice were obtained and identified using PCR method and Southern analysis. Integration rate of human G-CSF gene was 2.37% in mice. Foreign gene could also be identified in F1 and F2 transgenic mice. Expression levels of human G-CSF in transgenic mouse milk were 120-250 ng/ml.

[Studies of foreign gene integeation during embryo early development].

There are still some problems in transgenic animals. Gene transfer, for example, reamins a difficult and costly task for animals, the vectors carrying the gene coding for the proteins of interest are of unpredictable efficiency. Therefore, it is important to identify foreign gene integration in genomose before transferring fertilized eggs to receptors, in order to increase efficiency of producing transgenic animal. In this paper, the construct that mice whey acid protein (WAP) gene promoter directs G-CSF gene was used to microinject fertilized eggs of mice. Fertilized eggs containing foreign gene were measured by using PCR method. The results showed that 100%, 77.7% and 44.4% retentions of foreign gene were achieved in 1, 2 and 8 cell-stage, respectively. Two part homologous recombination fragments were constructed and coinjected in to fertilized eggs of mice. PCR amplification fragment went beyond this homologous recombination area. If foreign gene could not integrate in to genomose, the fragment of PCR amplification could not be produced during embryo development. The results showed that the rationes of foreign gene integrated in to genomoes in 1, 2 and 8 cell-stage were 11.1%, 55.5% and 44.4%, respectively. This method might provide us a way to screen transgenic eggs when we use embryo section technique in farm animal.