Polar metals by geometric design.

Gauss's law dictates that the net electric field inside a conductor in electrostatic equilibrium is zero by effective charge screening; free carriers within a metal eliminate internal dipoles that may arise owing to asymmetric charge distributions. Quantum physics supports this view, demonstrating that delocalized electrons make a static macroscopic polarization, an ill-defined quantity in metals--it is exceedingly unusual to find a polar metal that exhibits long-range ordered dipoles owing to cooperative atomic displacements aligned from dipolar interactions as in insulating phases. Here we describe the quantum mechanical design and experimental realization of room-temperature polar metals in thin-film ANiO3 perovskite nickelates using a strategy based on atomic-scale control of inversion-preserving (centric) displacements. We predict with ab initio calculations that cooperative polar A cation displacements are geometrically stabilized with a non-equilibrium amplitude and tilt pattern of the corner-connected NiO6 octahedral--the structural signatures of perovskites--owing to geometric constraints imposed by the underlying substrate. Heteroepitaxial thin-films grown on LaAlO3 (111) substrates fulfil the design principles. We achieve both a conducting polar monoclinic oxide that is inaccessible in compositionally identical films grown on (001) substrates, and observe a hidden, previously unreported, non-equilibrium structure in thin-film geometries. We expect that the geometric stabilization approach will provide novel avenues for realizing new multifunctional materials with unusual coexisting properties.

[Application of 3D-printed navigation plate in pulsed radiofrequency therapy of dorsal root ganglion in thoracic postherpetic neuralgia].

Objective: To evaluate the accuracy, efficacy and safety of 3D-printed personalized navigation template in the treatment of thoracic postherpetic neuralgia (PHN) with dorsal root ganglion pulsed radiofrequency (DRG-PRF). Methods: A total of 63 patients with thoracic PHN from March 2019 to December 2020 in Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School were enrolled and randomly divided into study group (n=31) and control group (n=32) by random number table method. The study group received DRG-PRF treatment assisted by 3D-printed navigation template, while the control group received DRG-PRF treatment guided by conventional CT. The one-time success rate of puncture, the incidence of puncture times ≥3, the number of punctures, puncture time, visual analogue scale (VAS) score and surgical complications between the two groups were compared. Results: The one-time success rate of puncture in study group was 84.9% (79/93), which was higher than that of control group [30.2% (29/96)] (P<0.001). The incidence of puncture times ≥3, the number of punctures, puncture time in study group were 4.3% (4/93), 1 (1, 1) and 2.9 (2.8, 3.0) min, respectively, which were lower than that of the control group [21.9% (21/96), 2(1, 3), 9.0 (4.5, 12.9) min, respectively] (all P<0.01). No difference was found in VAS score at each time point before and after surgery between the two groups (all P>0.05). There was one case of pleura puncture in the control group, but no other complications such as straying into vertebral canal, hematoma, spinal cord injury, limb movement disorder, infection were found in the two groups. Conclusions: 3D-printed personalized navigation template is an effective method to guide DRG-PRF for the treatment of thoracic postherpetic neuralgia. It can significantly improve the surgical efficiency of DRG-PRF, but has no significant effect on the surgical efficacy.

Artificially engineered superlattices of pnictide superconductors.

Significant progress has been achieved in fabricating high-quality bulk and thin-film iron-based superconductors. In particular, artificial layered pnictide superlattices offer the possibility of tailoring the superconducting properties and understanding the mechanism of the superconductivity itself. For high-field applications, large critical current densities (J(c)) and irreversibility fields (H(irr)) are indispensable along all crystal directions. On the other hand, the development of superconducting devices such as tunnel junctions requires multilayered heterostructures. Here we show that artificially engineered undoped Ba-122/Co-doped Ba-122 compositionally modulated superlattices produce ab-aligned nanoparticle arrays. These layer and self-assemble along c-axis-aligned defects, and combine to produce very large J(c) and H(irr) enhancements over a wide angular range. We also demonstrate a structurally modulated SrTiO3(STO)/Co-doped Ba-122 superlattice with sharp interfaces. Success in superlattice fabrication involving pnictides will aid the progress of heterostructured systems exhibiting new interfacial phenomena and device applications.

Electrical transport in ion beam created InAs nanospikes.

Ion beam irradiation has previously been demonstrated as a method for creating nanowire-like semiconductor nanostructures, but no previous studies have reported on the electrical properties of those structures. In this work we describe the creation and in situ transmission electron microscopy electrical characterization of nanoscale InAs spike structures on both InAs and InP substrates fabricated using a focused ion beam erosion method. Those InAs 'nanospikes' are found to possess internal structures with varying amounts of ion damaged and single crystalline material. Nanospike electrical behavior is analyzed with respect to model electronic structures and is similar to cases of barrier limited conduction in nanowires. The different electrical responses of each nanospike are found to be the result of variation in their structure, with the conductivity of InAs nanospikes formed on InAs substrates found to increase with the degree of nanospike core crystallinity. The conductivity of InAs nanospikes formed on InP substrates does not show a dependence on core crystallinity, and may be controlled by the other internal barriers to conduction inherent in that system.

Ferroelastic switching for nanoscale non-volatile magnetoelectric devices.

Multiferroics, where (anti-) ferromagnetic, ferroelectric and ferroelastic order parameters coexist, enable manipulation of magnetic ordering by an electric field through switching of the electric polarization. It has been shown that realization of magnetoelectric coupling in a single-phase multiferroic such as BiFeO(3) requires ferroelastic (71 degrees, 109 degrees) rather than ferroelectric (180 degrees) domain switching. However, the control of such ferroelastic switching in a single-phase system has been a significant challenge as elastic interactions tend to destabilize small switched volumes, resulting in subsequent ferroelastic back-switching at zero electric field, and thus the disappearance of non-volatile information storage. Guided by our phase-field simulations, here we report an approach to stabilize ferroelastic switching by eliminating the stress-induced instability responsible for back-switching using isolated monodomain BiFeO(3) islands. This work demonstrates a critical step to control and use non-volatile magnetoelectric coupling at the nanoscale. Beyond magnetoelectric coupling, it provides a framework for exploring a route to control multiple order parameters coupled to ferroelastic order in other low-symmetry materials.

Template engineering of Co-doped BaFe2As2 single-crystal thin films.

Understanding new superconductors requires high-quality epitaxial thin films to explore intrinsic electromagnetic properties and evaluate device applications. So far, superconducting properties of ferropnictide thin films seem compromised by imperfect epitaxial growth and poor connectivity of the superconducting phase. Here we report new template engineering using single-crystal intermediate layers of (001) SrTiO(3) and BaTiO(3) grown on various perovskite substrates that enables genuine epitaxial films of Co-doped BaFe(2)As(2) with a high transition temperature (T(c,rho=0) of 21.5 K, where rho=resistivity), a small transition width (DeltaT(c)=1.3 K), a superior critical current density J(c) of 4.5 MA cm(-2) (4.2 K) and strong c-axis flux pinning. Implementing SrTiO(3) or BaTiO(3) templates to match the alkaline-earth layer in the Ba-122 with the alkaline-earth/oxygen layer in the templates opens new avenues for epitaxial growth of ferropnictides on multifunctional single-crystal substrates. Beyond superconductors, it provides a framework for growing heteroepitaxial intermetallic compounds on various substrates by matching interfacial layers between templates and thin-film overlayers.

Multifunctional Chiral Three-Dimensional Phosphite Frameworks Showing Dielectric Anomaly and High Proton Conductivity.

Chair 3D Co(II) phosphite frameworks have been prepared by the ionothermal method. It belongs to chiral space group P3221, and the whole framework can be topologically represented as a chiral 4-connected qtz net. It shows a multistep dielectric response arising from the reorientation of Me2-DABCO in the chiral cavities. It can also serve as a pron conductor with high conductivity, 1.71 × 10-3 S cm-1, at room temperature, which is attributed to the formation of denser hydrogen-bonding networks providing efficient proton-transfer pathways.

In-plane quasi-single-domain BaTiO3 via interfacial symmetry engineering.

The control of the in-plane domain evolution in ferroelectric thin films is not only critical to understanding ferroelectric phenomena but also to enabling functional device fabrication. However, in-plane polarized ferroelectric thin films typically exhibit complicated multi-domain states, not desirable for optoelectronic device performance. Here we report a strategy combining interfacial symmetry engineering and anisotropic strain to design single-domain, in-plane polarized ferroelectric BaTiO3 thin films. Theoretical calculations predict the key role of the BaTiO3/PrScO3 [Formula: see text] substrate interfacial environment, where anisotropic strain, monoclinic distortions, and interfacial electrostatic potential stabilize a single-variant spontaneous polarization. A combination of scanning transmission electron microscopy, piezoresponse force microscopy, ferroelectric hysteresis loop measurements, and second harmonic generation measurements directly reveals the stabilization of the in-plane quasi-single-domain polarization state. This work offers design principles for engineering in-plane domains of ferroelectric oxide thin films, which is a prerequisite for high performance optoelectronic devices.

Ferroelectricity in strain-free SrTiO3 thin films.

Biaxial strain is known to induce ferroelectricity in thin films of nominally nonferroelectric materials such as SrTiO3. By a direct comparison of the strained and strain-free SrTiO3 films using dielectric, ferroelectric, Raman, nonlinear optical and nanoscale piezoelectric property measurements, we conclude that all SrTiO3 films and bulk crystals are relaxor ferroelectrics, and the role of strain is to stabilize longer-range correlation of preexisting nanopolar regions, likely originating from minute amounts of unintentional Sr deficiency in nominally stoichiometric samples. These findings highlight the sensitive role of stoichiometry when exploring strain and epitaxy-induced electronic phenomena in oxide films, heterostructures, and interfaces.

Room-temperature ferroelectricity in strained SrTiO3.

Systems with a ferroelectric to paraelectric transition in the vicinity of room temperature are useful for devices. Adjusting the ferroelectric transition temperature (T(c)) is traditionally accomplished by chemical substitution-as in Ba(x)Sr(1-x)TiO(3), the material widely investigated for microwave devices in which the dielectric constant (epsilon(r)) at GHz frequencies is tuned by applying a quasi-static electric field. Heterogeneity associated with chemical substitution in such films, however, can broaden this phase transition by hundreds of degrees, which is detrimental to tunability and microwave device performance. An alternative way to adjust T(c) in ferroelectric films is strain. Here we show that epitaxial strain from a newly developed substrate can be harnessed to increase T(c) by hundreds of degrees and produce room-temperature ferroelectricity in strontium titanate, a material that is not normally ferroelectric at any temperature. This strain-induced enhancement in T(c) is the largest ever reported. Spatially resolved images of the local polarization state reveal a uniformity that far exceeds films tailored by chemical substitution. The high epsilon(r) at room temperature in these films (nearly 7,000 at 10 GHz) and its sharp dependence on electric field are promising for device applications.

[Association between fresh fruit consumption and glycemic control in patients with type 2 diabetes].

Objective: To investigate the association between fresh fruit consumption and status of glycemic control, among patients with type 2 diabetes mellitus (T2DM). Methods: Using the stratified cluster sampling method, a cross-sectional study was conducted among 19 473 diabetic patients who were under the Disease Management Program related to the National Basic Public Health Service in Changshu county, Huai'an and Qinghe districts of Huai'an city from December 2013 to January 2014, under the combination of fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) methods, the glycemic control status in T2DM patients was assessed. Multiple logistic regression method was used to explore the relationship between fresh fruit consumption and status of glycemic control among T2DM patients. Results: 62.4% of the T2DM patients reported their amount of fruits intake in the past year. Both the levels of FPG and HbA1c decreased in T2DM patients, when the frequency and amount of fresh fruit consumption were increasing. Compared with patients who did not take fresh fruits, the risk of poor glycemic control in patients with fresh fruit consumption of 1-4 times/week and ≥5 times/week decreased 20% (OR=0.80, 95%CI: 0.73-0.87) and 30% (OR=0.70, 95%CI: 0.62-0.80), respectively. Patients with fruit consumption of 50-99 g/day and ≥100 g/day had lower risk of poor glycemic control, with ORs (95%CI) as 0.71 (95%CI: 0.62-0.83) and 0.68 (95%CI: 0.59-0.78), respectively. Conclusions: The association of fresh fruit intake and glycemic control was statistically significant in patients with type 2 diabetes. With the increase of frequencies and amounts of fresh fruit consumption, the levels of FPG and HbA1c showed a decreasing trend. Our findings suggested that fresh fruit intake seemed helpful for glycemic control.

Chemically specific termination control of oxide interfaces via layer-by-layer mean inner potential engineering.

Creating oxide interfaces with precise chemical specificity at the atomic layer level is desired for the engineering of quantum phases and electronic applications, but highly challenging, owing partially to the lack of in situ tools to monitor the chemical composition and completeness of the surface layer during growth. Here we report the in situ observation of atomic layer-by-layer inner potential variations by analysing the Kikuchi lines during epitaxial growth of strontium titanate, providing a powerful real-time technique to monitor and control the chemical composition during growth. A model combining the effects of mean inner potential and step edge density (roughness) reveals the underlying mechanism of the complex and previously not well-understood reflection high-energy electron diffraction oscillations observed in the shuttered growth of oxide films. General rules are proposed to guide the synthesis of atomically and chemically sharp oxide interfaces, opening up vast opportunities for the exploration of intriguing quantum phenomena at oxide interfaces.

[Association between smoking/smoking cessation and glycemic control in male patients with type 2 diabetes].

Objective: To explore the association of smoking and smoking cessation with glycemic control in male patients with type 2 diabetes. Methods: From December 2013 to January 2014, a total of 7 763 male patients with type 2 diabetes, who received national basic public health service in Changshu county of Suzhou city, Huai'an and Qinghe districts of Huai'an city, Jiangsu province, were recruited by cluster sampling. Questionnaire survey and anthropometric measurements were conducted, and fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) levels were measured. Multiple linear regression model was used to evaluate the association of smoking and smoking cessation with glycemic control. Results: The prevalence of current smoking was 45.5% in male patients with type 2 diabetes. The levels of FPG and HbA1c increased with number of cigarettes smoked per day compared with non-smokers (P<0.001). Among patients with drug treatment, the average increase of HbA1c level in current smokers with smoking duration ≥30 years and smoking index ≥40 pack-years were 0.27% (95%CI: 0.05%-0.49%) and 0.38% (95%CI: 0.23%-0.53%), respectively. FPG and HbA1c level decreased obviously with smoking cessation years among former smokers (P<0.05). Among the patients receiving no drug treatment, no dose-response relationships were observed between smoking duration, smoking cessation years and levels of FPG and HbA1c. Conclusion: Cigarette smoking was negatively related with glycemic control in male type 2 diabetes patients, especially in patients with drug treatment. Smoking cessation may be beneficial for glycemic control. Smoking cessation should be encouraged for diabetes patients as early as possible.

The high affinity Fc gamma receptor (CD64) induces phagocytosis in the absence of its cytoplasmic domain: the gamma subunit of Fc gamma RIIIA imparts phagocytic function to Fc gamma RI.

The high affinity Fc gamma receptor, Fc gamma RI, is unique among the three classes of macrophage Fc gamma receptors not only in its affinity for IgG, but also in the structure of its cytoplasmic domain. Fc gamma RIIA and the gamma subunit of Fc gamma RIIIA have tyrosine-containing motifs within their cytoplasmic domains that are phosphorylated when crosslinked and that are required for phagocytosis by COS-1 cell transfectants. In contrast to these other Fc gamma receptors, Fc gamma RI does not contain cytoplasmic tyrosines and does not induce phagocytosis in COS-1 transfectants. We transfected wild-type (WT) and mutant (MT) Fc gamma RI lacking the cytoplasmic domain into COS-1 cells and murine macrophages and assessed phagocytosis using IgG-coated red blood cells (RBCs) and RBCs conjugated with Fab anti-human Fc gamma RI monoclonal antibody (mAb). Fc gamma RI, in contrast to Fc gamma RIIA, did not induce phagocytosis in COS cells. However, both WT and MT Fc gamma RI induced phagocytosis in murine macrophages, and phagocytosis was inhibited by the tyrosine kinase inhibitor tyrphostin 23. Human monocytes also phagocytosed Fc gamma RI-targeted RBCs, and activation of Fc gamma RI on monocytes with Fab anti-Fc gamma RI induced phosphorylation of Fc gamma RII on tyrosine residues. However, Fc gamma RI activation of Fc gamma RI-Fc gamma RIIA COS-1 cotransfectants did not induce tyrosine phosphorylation of Fc gamma RIIA, and coexpression of Fc gamma RI and Fc gamma RIIA in COS cells did not confer Fc gamma RI phagocytic capability. In contrast, coexpression in COS-1 cells of Fc gamma RI with the gamma subunit of Fc gamma RIIIA conferred phagocytic function to both Fc gamma RI and the MT Fc gamma RI lacking the cytoplasmic domain. Thus, Fc gamma RI does not require its cytoplasmic domain to mediate a phagocytic signal and interacts with the gamma subunit of Fc gamma RIIIA to induce phagocytosis.

Rapid screening of monoclonal antibodies: new 'microstick' radioimmunoassay.

A new system for assaying monoclonal antibodies consisting of an 8 x 12 array of sticks which fits into a 96-well microtiter plate is described. Tests using virus specific monoclonal antibodies and virus proteins demonstrated sensitivity equivalent to the conventional microtiter plate assay. Antibody production, antigen specific antibody, and immunoglobulin isotypes could be measured under sterile conditions directly in the original fusion mixture wells and with much greater rapidity than with the microtiter plate assay.

Synthesis and antimalarial activities of several fluorinated artemisinin derivatives.

The carbonyl groups in several artemisinin derivatives were converted into geminal difluorinated compounds on treatment with diethylaminosulfur trifluoride. A number of other mono- and polyfluorinated artemisinin derivatives were prepared. Their in vitro antimalarial activities were all equal to or greater than the nonfluorinated analogs or precursors.

Syntheses and antimalarial activities of N-substituted 11-azaartemisinins.

A two-step reaction sequence between artemisinin and methanolic ammonia followed by treatment with Amberlyst 15 yielded 11-azaartemisinin in 65% yield. Substituting a variety of primary alkyl- and heteroaromatic amines for ammonia in the reaction sequence yields N-substituted 11-azaartemisinins in similar or greater yield. When Amberlyst 15 is replaced by a mixture of sulfuric acid/silica gel, both 11-azaartemisinin and the expected metabolite, 10-azadesoxyartemisinin, are formed in 45% and 15% yields, respectively. In vitro and in vivo test data for a number of novel N-substituted 11-azaartemisinins, against drug-resistant strains of Plasmodium falciparum, show they possess antimalarial activities equal to or greater than that of artemisinin. The most active derivative, N-(2'-acetaldehydo)-11-azaartemisinin, 17, was 26 times more active in vitro and 4 times more active in vivo than artemisinin.

The functional hepatic volume assessed by 99mTc-GSA hepatic scintigraphy.

The accuracy of measurement of the functional hepatic volume by single photon emission computed tomography (SPECT) with 99mTc-galactosyl serum albumin (99mTc-GAS) was evaluated. 99mTc-GSA planar scintigraphic images were obtained dynamically and the hepatic SPECT imaging was then performed in 25 patients with hepatobiliary tumors. The patients were divided into 4 groups with normal hepatic function, and mild, moderate and severe hepatic dysfunction. The functional hepatic volume determined by SPECT was compared with the morphological hepatic volume determined by compute tomography. The ratio of the hepatic volumes obtained by the two methods was calculated. The mean hepatic volume ratio was 96.6 +/- 2.3% in the normal hepatic function group and 95.9 +/- 2.2% in the mild dysfunction group (n.s.). In both the moderate and severe hepatic dysfunction groups, the hepatic volume ratio was smaller than that in the normal group (87.9 +/- 5.2%, p < 0.0001, and 71.9 +/- 7.6%, p < 0.0001, respectively). There was a linear correlation between the hepatic volume ration and various indices of reserve hepatic function, such as LHL15 (r = 0.83, p < 0.0001), HH15(r = 0.74, p < 0.0001), and ICG15 (r = 0.75, p < 0.0005). These results indicate that the hepatic volume ratio is proportional to the severity of hepatic dysfunction, and suggest that the functional hepatic volume measured with 99mTc-GSA faithfully reflects the functioning hepatocyte mass. 99mTc-GSA scintigraphy and hepatic SPECT therefore provide information regarding global and regional reserve hepatic function.

Effect of ketotifen on the ultrastructure of the erythrocytic stages of Plasmodium yoelii.

The effect on the morphology of Plasmodium yoelii of ketotifen treatment was different from that of chloroquine and other antimalarial drugs. Following administration of a low dosage of ketotifen, the parasite first developed a multilamellate pellicular complex which resembled a medullary sheath and then developed vacuoles and cavitations. The development of large multilamellate whorls consisting of a pellicular structure enclosing cytoplasm was the typical change which occurred.

[Determination of allopurinol in tablets and urine by oscillopolarography].

Determination method of allopurinol has been studied by the second derivative oscillopolarography. Well-defined linear relationship between concentrations and the wave height in the range 3 X 10(-7)-1 X 10(-4) mol/L and 5 X 10(-7)-1 X 10(-4) mol/L was observed, respectively, in 0.50 mol/L H2SO4 and pH 5.5 HAc-NaAc buffer. The contents of allopurinol in tablets and urine were determined. The character of the electrode reaction was explored preliminarily.