Monolayer polar metals with large piezoelectricity derived from MoSi2N4.

The advancement of two-dimensional polar metals tends to be limited by the incompatibility between electric polarity and metallicity as well as dimension reduction. Here, we report polar and metallic Janus monolayers of the MoSi2N4 family by breaking the out-of-plane structural symmetry through Z (P/As) substitution of N. Despite the semiconducting nature of MoSi2X4 (X = N/P/As), four Janus MoSi2NxZ4-x monolayers are found to be polar metals owing to the weak coupling between the conducting electrons and electric polarity. The metallicity is originated from the Z substitution induced delocalization of occupied electrons in Mo-d orbitals. The out-of-plane electric polarizations around 1.5-15.7 pC m-1 are determined by the asymmetric out-of-plane charge distribution due to the non-centrosymmetric Janus structure. The corresponding out-of-plane piezoelectricity is further revealed as high as 18.7-73.3 pC m-1 and 0.05-0.25 pm V-1 for the piezoelectric strain and stress coefficients, respectively. The results demonstrate polar metallicity and high out-of-plane piezoelectricity in Janus MoSi2NxZ4-x monolayers and open new vistas for exploiting unusual coexisting properties in monolayers derived from the MoSi2N4 family.

Giant Magnetocaloric Effect in Magnets Down to the Monolayer Limit.

2D magnets can potentially revolutionize information technology, but their potential application to cooling technology and magnetocaloric effect (MCE) in a material down to the monolayer limit remain unexplored. Herein, it is revealed through multiscale calculations the existence of giant MCE and its strain tunability in monolayer magnets such as CrX3 (X = F, Cl, Br, I), CrAX (A = O, S, Se; X = F, Cl, Br, I), and Fe3 GeTe2 . The maximum adiabatic temperature change ( Δ T ad max $\Delta T_{{\rm{ad}}}^{\max }$ ), maximum isothermal magnetic entropy change, and specific cooling power in monolayer CrF3 are found as high as 11 K, 35 µJ m-2  K-1 , and 3.5 nW cm-2 under a magnetic field of 5 T, respectively. A 2% biaxial and 5% a-axis uniaxial compressive strain can remarkably increase Δ T ad max $\Delta T_{{\rm{ad}}}^{\max }$ of CrCl3 and CrOF by 230% and 37% (up to 15.3 and 6.0 K), respectively. It is found that large net magnetic moment per unit area favors improved MCE. These findings advocate the giant-MCE monolayer magnets, opening new opportunities for magnetic cooling at nanoscale.

Patient compliance with an anticoagulation management system based on a smartphone application.

We developed a novel anticoagulation management system (Anticlot Assistant) based on a smartphone application (App). This study was performed to evaluate patient compliance with Anticlot Assistant. This prospective case series study involved patients receiving warfarin therapy. The eligible patients were managed via Anticlot Assistant, and outcome data were analyzed. Thirty patients were recruited. The mean time within the therapeutic range (TTR) was 56.5% ± 26.2% and the mean patient compliance with Anticlot Assistant was 52.7% ± 40.4%. The patients in good compliance group had higher TTR (65.6 ± 25.0% vs. 40.0 ± 21.0%, P = 0.009), lower time in the extremely low range (9.4 ± 10.6% vs. 27.4 ± 13.2%, P = 0.000) and in the extremely high range (1.3 ± 2.8% vs. 14.1 ± 22.3%, P = 0.004) than those in poor compliance group. Logistic regression analysis revealed that receiving an education of > 6 years was the only independent predictor of good compliance (odds ratio 8.400, 95% confidence interval 1.274-55.394, P = 0.027). Patient compliance is critical important for good outcomes and it might increase with improvements in education and more widespread use of information technology. Although further improvement is needed, Anticlot Assistant is promising and this study offered valuable experiences for further research.

Sub-1 nm Nanowire Based Superlattice Showing High Strength and Low Modulus.

Polymers possess special dimension-dependent processing flexibility which is always absent in inorganic materials. Traditional inorganic nanowires own similar dimensions to polymers, but usually lack near-molecular diameters and the related properties. Here we report that inorganic nanowires with sub1 nm diameter and microscale length can be electrospinningly processed into superstructures including smooth fibers and large-area mat by tuning the viscosity and surface tension of the colloidal nanowires solution. These superstructures have shown both flexible texture and excellent mechanical properties (712.5 MPa for tensile strength, 10.3 GPa for elastic modulus) while retaining properties arising from inorganic components.

Robust Anti-Icing Performance of a Flexible Superhydrophobic Surface.

A material with superhydrophobic and anti-ice/de-icing properties, which has a micro-/nanostructured surface, is produced by a straightforward method. This material comprises a poly(dimethylsiloxane) (PDMS) microstructure with ZnO nanohairs and shows excellent water and ice repellency even at low temperatures (-20 °C) and relatively high humidity (90%) for over three months. These results are expected to be helpful for designing smart, non-wetting materials that can be adapted to low-temperature environments for the development of anti-icing systems.

Study of the Mechanical Behavior of Radially Grown Fivefold Twinned Nanowires on the Atomic Scale.

In situ bending tests and dynamic modeling simulations are for the first time revealing the mechanical behavior of copper nanowires (NW) with radially grown fivefold twin structures on the atomic scale. Combining the simulations with the experimental results it is shown that both the twin boundaries (TBs) and the twin center act as dislocation sources. TB migration and L-locks are readily observed in these types of radially grown fivefold-twin structures.

Two novel mutations of the LDL receptor gene associated with familial hypercholesterolemia in a Chinese family.

BACKGROUND: Familial hypercholesterolemia (FH) is a type of dominant autosomal disease that causes high levels of plasma low-density lipoprotein cholesterol (LDL-C). In the past years, molecular data related to FH were limited in China. Now, to gain more information about FH, we analyzed one proband with a severe FH phenotype as well as his relatives. METHODS: After the entire coding sequence and the intron-exon junctions of the low-density lipoprotein receptor (LDLR) gene were amplified using PCR, we sequenced the LDLR gene of a Chinese FH family. RT-PCR was used to detect changes in the mRNA. RESULTS: Two novel mutations were identified in the LDLR gene of this family. One, W165X, was a G > A substitution at the third nucleotide of codon 165. The other, IVS5-1G > A, was also a G > A substitution at the acceptor splice site of intron 5. The most striking discovery is that the proband was heterozygous for W165X but homozygous for IVS5-1G > A. The cDNA sequencing showed that the IVS5-1G > A mutation caused the insertion of 10 nucleotides, namely GCTCTCACAA, between exon 5 and exon 6. CONCLUSIONS: The two nucleotide variations are thought to be the FH-causing mutations because the co-segregation of the mutant allele with the phenotype of FH has been shown in this Chinese family. These data show an increase in the mutational spectrum of FH in China and verify a scarce mutational form in the LDLR gene.

[Multifactor analysis of postoperative mechanical ventilation supporting time in infants with congenital heart diseases].

OBJECTIVE: To analyze the multiple factors affecting the postoperative mechanical ventilation supporting time in infants less than 10 kg with simple congenital heart diseases and to seize time by the forelock of extube and improve the outcome of surgical treatment. METHODS: Data of 231 infants less than 10 kg with atrial septal defect(ASD),ventricular septal defect, and combining patent ductus arteriosus were retrospectively analyzed. The multivaricate stepwise logistic regression statistics were done for the predisposing factors affecting the ventilative supporting time. RESULTS: The ventilative supporting time was 3~375 (average 23.5 h) h. The multivaricate stepwise logistic regression analysis indicated that severe pulmonary hyperpressure, cross-cramp aortic time, cardiopulmonary bypass time, preoperational pulmonary infection, membrane oxygenator, modified ultrafiltration, weight, and postoperative complications were significantly correlated to the ventilative supporting time. CONCLUSION: Severe pulmonary hyperpressure, preoperational pulmonary infection, long cross-cramp aortic time, long cardiopulmonary bypass time, postoperative complications all prolong the ventilation supporting time; the use of membrane oxygenator and modified ultrafiltration during the operation and big weight can diminish the pulmonary complications and shorten the ventilation supporting time.

[Surgical treatment of partial atrioventricular septal defect].

OBJECTIVE: To summarize the experience of surgical treatments of partial atrioventricular septal defect in 60 patients. METHODS: From April 1999 to April 2004, 60 patients of partial atrioventricular septal defect were operated. Fifty-eight patients were performed with suture of the cleft of mitral valve and the other 2 were given mitral valve replacement; For closure of primum ASD, 53 patients with pericardial patches and 7 with Dacron patches. Coronary sinus was baffled to left atrium with kirklin procedure in 35 cases and baffled to right atrium with McGoon procedure in other 25 cases. Correct the accompanying cardiac deformity at the same time. RESULTS: The hospital mortality was 3.3% (2/60) due to low cardic output syndrome. The incidence rate of complete atrioventricular block was 8.00% (2/ 35) in the group with Kirklin procedure and 6.06% (2/25) in the group with McGoon procedure. There was no statistical significance between the 2 groups (P > 0.05). The follow-up was from 1 month to 5 years, and there was no late death. All cardiac function were improved except middle mitral regurgitation in 1 patient. CONCLUSION: Reasonable operative design, refined procedures, avoiding damage to conducting bundles and proper perioperative management are the key points in improving theraeutic effect.

[Diagnosis and surgical treatment of 102 cases of ventricular septal defect with patent ductus arteriosus].

OBJECTIVE: To summarize the experience of diagnosis and surgical treatment of ventricular septal defect with patent ductus arteriosus. METHODS: We retrospectively analyzed the clinical data of 102 cases of ventricular septal defect combined with patent ductus arteriosus who underwent surgical treatment. Preoperative ultrasonic cardiogram (UCG) showed ventricular septal defect combined with patent ductus arteriosus in 82 cases and ventricular septal defect in 20 cases. RESULTS: The hospital mortality was 4.9% (5/102). The reasons for death included low cardiac output syndrome (1 case), pulmonary hypertension crisis (2 cases) and respiratory failure (2 cases). In the remaining patients,the perioperative complications included lung infection (7 cases), pulmonary atelectasis (5 cases), hydrothorax (1 case), and pulmonary hypertension crisis (2 cases); and all the 15 patients recovered lastly. The pulmonary hypertension of all living patients decreased to some degree. The therapeutical effectiveness was satisfactory. CONCLUSION: Ventricular septal defect with patent ductus arteriosus is easy to be confused with ventricular septal defect clinically. At the same time,it is diffcult to form a correct diagnosis in some patients by UCG preoperatively. To prevent the occurrence of perfusive lung, it is important to reinforce preoperative diagnosis and exploration during operation. Because pulmonary hypertension in patients with ventricular septal defect with patent ductus arteriosus emerges early and develops quickly, it tends to result in organic pulmonary hypertension which can make patients lose operation chances and influence the long-term therapeutical effect. Surgical operation should be performed as soon as possible. Optimal operative timing and proper perioperative management play important roles in surgical results.