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Objective Twin-Reversed Arterial Perfusion (TRAP) sequence is a rare complication of monochorionic multiple gestation. Conservative management should be considered if there is no poor prognostic factor. Case report This is a 35 year-old female with twin pregnancy with acardiac monster. Under the request of the patient, there was no intervention during the whole pregnancy. We keep regular and close sonography weekly follow up. There was no maternal complication and there was also no heart failure sign or polyhydramnios of the donor twin. Minimal blood flow was noted at the anastomotic vessels under the sonography at late gestational age. Due to breech presentation, cesarean section was performed at gestational age 37 + 1/7 weeks. She delivers a healthy baby smoothly. Conclusion Antenatal sonography is an important tool to evaluate the fetus status. Under special condition, term pregnancy is still possible without any treatment. Case report Twin reversed arterial perfusion syndrome in a monochorionic monoamniotic twin pregnancy.

Objective Skill competence is essential for nursing students and experiential teaching method has become increasingly popular in China's nursing education. To systematically evaluate the effects of experiential teaching method on the development of nursing students’ skill competence, and to provide evidence for nursing education. Methods The China National Knowledge Infrastructure, VIP, Wanfang Data, PubMed, and Web of Science databases were searched from their inception until November 28, 2019. We screened the studies according to inclusion and exclusion criteria, extracted the data, and assessed the quality. Then, a meta-analysis was conducted. Results Totally 15 studies were included, and 1,633 nursing students were analyzed by Review Manager5.3 and Stata15.1 software. The results show that the experiential teaching method can significantly improve nursing students’ nursing skills such as training (SMD = 1.05, 95% CI: 0.95–1.16, P = 0.000), learning interest (ES = 0.93, 95% CI: 0.79–1.06), ability to analyze and solve problems (ES = 0.75, 95% CI: 0.55–0.94), ability to judge and innovative thinking (ES = 1.01, 95% CI: 0.77–1.25), abilities of understanding and perception (ES = 0.59, 95% CI: 0.34–0.83), and teaching satisfaction (ES = 1.26, 95% CI: 1.13–1.4). Conclusions The results suggest that the experiential teaching method is more effective for the nursing students’ skill competence than traditional teaching in China. However, due to the heterogeneity and bias risk, a large sample and high-quality studies are needed in future to confirm its effectiveness.

OBJECTIVE: To investigate the outcome of endodontic microsurgery and analyze the potential prognostic factors, and to evaluate the value of surgical classification by Kim and Kratchman. METHODS: Collecting clinical examination and radiographical examination of endodontic microsurgery cases (which were followed up at least 1 year), which were classified according to Kim and Kratchman, and we analyzed the outcome of endodontic microsurgery and its potential prognostic factors. RESULTS: 302 patients (400 teeth) who received endodontic microsurgery were included. The one year success rate of endodontic microsurgery was 94.25%. Different classification had significant influences on the outcome of endodontic microsurgery (P0.05). CONCLUSION: Endodontic microsurgery is an effective treatment method for saving affected teeth, and it can get a good result. Tooth position and classification are the potential prognostic factors. The surgical classification of Kim and Kratchman can help to predict the outcome of endodontic microsurgery.

Coronin-3 (coronin-1C), a homotrimer F-actin-binding protein, has been reported to be important for metastasis in several types of cancers such as lung cancer, gastric cancer, and breast cancer. Here, we present an investigation of the expression and function of coronin-3 in renal cell cancer for the first time. We also confirmed that miR-26 directly targets coronin-3 and down-regulates its expression by western blot assay and dual-luciferase reporter system. The results of MTT and colony formation assay showed that miR-26 suppressed cell proliferation. Wound healing and transwell assay revealed that miR-26 inhibited migration and invasion of renal cancer cell. Moreover, overexpression of coronin-3 could reverse the miR-26-induced inhibition in cell growth and metastasis. Thus, our study suggests that coronin-3 should serve as a potential therapeutic target in renal cell cancer and provide a candidate for miRNA therapy.

With increasing of the development of smart grid and restructuring of the power industry, the efficient operation schedule for a time-of-use (TOU) rate industrial user may become a more important problem in smart cities. This paper develops a stochastic direct search method (SDSM) to solve the operating schedule of a TOU rate industrial user. To effectively overcome the coupling constraints of the operating schedule problem, the three-state dynamic programming (DP) is also incorporated into the SDSM to augment the direct stochastic search procedure. A TOU rate industrial customer of Taiwan Power Company (TPC) is used as an example to validate the feasibility of the SDSM algorithm for the application considered. Numerical experiments are included to illustrate the effects of battery energy storage system (BESS) on operating schedule and to assess the impact and economic benefits of the installation of renewable energy sources (RES) for the TOU rate industrial customer.

This paper concerns the smoke control modes and the critical ventilation velocity when the subway tunnel on fires. The standard for the smoke control mode is making sure the smoke exhausting in the shortest way. The critical ventilation velocity means it is just sufficient to prevent the smoke spreading upstream. The critical velocity in different heat release rates obtained though theoretical analysis and computer simulation. In the end, a simple formula to calculate the critical velocity can be fitting out.

The environmental deterioration of the subway station and the safety of the personnel evacuation under platform train fire are researched. The critical fire danger condition is proposed and the time calculation method of evacuation is determined. A platform train fire in a subway station is simulated by the Fire Dynamics Simulator software. Then the available egress time can be got by analyzing the fire temperature and smoke concentration change with time. At the same time, the required egress time is studied through theoretical analysis and computer simulation by software Building Exodus. The results showed that smoke exhaust rate is very important to the smoke control under platform train fire. And the stair evacuation ability is the key to the whole evacuation.

Prestressed concrete (PC) box-girders with corrugated steel webs are one of the promising steel concrete composite structures applied to highway bridges. Although the basic structural characteristics including bending, shearing and torsion, etc., have been paid much attention, few researches on the seismic performance of this type of bridges are found, especially when the span of this type of bridges becomes larger and larger. In this paper, the seismic performance of one long-span PC box-girder bridge with corrugated steel webs is studied and compared with a conventional box-girder bridge with concrete webs, based on response spectrum analysis using ANSYS. The results show that, the vertical and transverse displacements of the box-girder with corrugated steel webs are slightly less than those of the box-girder with concrete webs, but the longitudinal displacement reverses, under the same earthquake excitation. The bending moments of representative sections of the box-girder bridge with corrugated steel webs are only about 70% ~ 90% of those of the corresponding conventional PC girder bridge. The results indicate that the box-girder bridge will have better seismic performance if the corrugated steel webs are adopted instead of the concrete webs, but it could also fulfill the tasks such as displacement control which resulted from stiffness reduction.

In EN1991-1-7 Eurocode 1: Part 1-7 Accidental Actions structural robustness is defined as ‘the ability of a structure to withstand events like fire, explosions, impact or consequences of human error without being damaged to an extent disproportionate to the original cause’. Accordingly, the principle of structural robustness is that local damage is acceptable, provided that it will not endanger the structure and that the overall load-carrying capacity is maintained during an appropriate length of time to allow the necessary emergency measures to be taken. For different structures the practical ways to achieve robustness are different. Lots of through arch bridges with hangers have been built throughout the world. However, the structural collapse may happen due to the hanger's damage or failure if the bridge is not designed appropriately. In this paper, the structural robustness of the through arch bridges with vertical hangers are discussed and verified by an example. Based on this study, a few practical suggestions are put forward to achieve the structural robustness for the future through arch bridges' design.

It is well-known that in modern through arch bridges the suspenders are important components since they connect the bridge deck and the arch ribs. When the suspender break happens, the other components of the through arch bridge will be impacted successively. Sometimes, the collapse of bridge deck may be induced by the possible suspender break. In this paper, the impact effect on the remaining components of the through arch bridge due to the suspender break is studied and obtained by appropriate simulation and time-history analysis using the comprehensive commercial software ANSYS, which is based on a real through arch bridge. The study in this paper will be helpful to carry out the reasonable design of the through arch bridge.

It is well-known that in modern through and half-through arch bridges the suspenders are important components since they connect the bridge deck and the arch ribs. The collapse of bridge deck or arch ribs may be induced once one or more suspenders are broken. In this paper, the traditional design way of the suspenders in through and half-through arch bridges is discussed first. Based on the discussion, a new way to design suspenders for arch bridges is then put forward. The reasonability and robustness of this new way is proved by a numerical example based on a real through arch bridge using the comprehensive commercial software ANSYS. It can be concluded from the analysis in this paper that the new way to design the suspenders for the through and half-through arch bridges can assure the safety of the bridge effectively even though one or more suspenders happen to break.

Q345qC steel is widely used in corrugated steel web. In this paper, the fatigue strength of Q345qC steel between 105~109 cycles was investigated using the ultrasonic fatigue testing technique, with a loading frequency of 20 kHz. The fracture surfaces of specimens were observed with scanning electron microscopy (SEM). The experimental results show that the S-N curve of Q345qC steel continues to decrease with the increase of the number of cycles between 105 and 109 cycles and does not generally exhibit a plateau beyond 107 cycles. The observation of fracture surface shows that the mechanism of fatigue failure is similar in both case of ultrasonic fatigue and conventional fatigue in long life regime. Cracks initiate from a mass defect of specimen surface or an interior inclusion.

Effects of AlO x interfacial layer in the W/AlO x /TaO x /TiN structures have been investigated for the first time. This RRAM device shows long endurance of 10 6 cycles and good retention at 85°C for a low current compliance of 100 μA. A physics based simulation is studied to understand the set and reset mechanism of RRAM. The nature of ions migration, potential profile and temperature of filament during switching is explained using numerical simulation done by MATLAB.

Low current cross-point memory using gadolinium-oxide switching material in an IrO x /GdO x /W structure has been investigated for the first time. Memory device shows low current bipolar resistive switching phenomena and self-compliance phenomena as well, repeatable switching cycles, good uniformity, long program/erase endurance of >60k every cycles, and good data retention of >104 s at a low CC of 50 µA.

Conductive and transparent multilayer thin films consisting of three alternating layers (TiO2/Ag/SiO2, TAS) have been fabricated for applications as transparent conducting oxides. Metal oxide and metal layers were prepared by electron-beam evaporation with ion-assisted deposition, and the optical and electrical properties of the resulting films as well as their energy bounding characteristics and microstructures were carefully investigated. The optical properties of the obtained TAS material were compared with those of well-known transparent metal oxide glasses such as ZnO/Ag/ZnO, TiO2/Ag/TiO2, ZnO/Cu/ZnO, and ZnO/Al/ZnO. The weathering resistance of the TAS film was improved by using a protective SiO2 film as the uppermost layer. The transmittance spectra and sheet resistance of the material were carefully measured and analyzed as a function of the layer thickness. By properly adjusting the thickness of the metal and dielectric films, a low sheet resistance of 6.5 ohm/sq and a high average transmittance of over 89% in the 400 to 700 nm wavelength regions were achieved. We found that the Ag layer played a significant role in determining the optical and electrical properties of this film.

Genetic variation plays a significant role in maintaining the evolutionary potential of a species. Comparing the patterns of adaptive and neutral diversity in extant populations is useful for understanding the local adaptations of a species. In this study, we determined the fine-scale genetic structure of 6 extant populations of the giant panda (Ailuropoda melanoleuca) using mtDNA and DNA fingerprints, and then overlaid adaptive variations in 6 functional Aime-MHC class II genes (DRA, DRB3, DQA1, DQA2, DQB1, and DQB2) on this framework. We found that: (1) analysis of the mtDNA and DNA fingerprint-based networks of the 6 populations identified the independent evolutionary histories of the 2 panda subspecies; (2) the basal (ancestral) branches of the fingerprint-based Sichuan-derived network all originated from the smallest Xiaoxiangling (XXL) population, suggesting the status of a glacial refuge in XXL; (3) the MHC variations among the tested populations showed that the XXL population exhibited extraordinary high levels of MHC diversity in allelic richness, which is consistent with the diversity characteristics of a glacial refuge; (4) the phylogenetic tree showed that the basal clades of giant panda DQB sequences were all occupied by XXL-specific sequences, providing evidence for the ancestor-resembling traits of XXL. Finally, we found that the giant panda had many more DQ alleles than DR alleles (33∶13), contrary to other mammals, and that the XXL refuge showed special characteristics in the DQB loci, with 7 DQB members of 9 XXL-unique alleles. Thus, this study identified XXL as a glacial refuge, specifically harboring the most number of primitive DQB alleles.

Five new hydroanthraquinone derivatives, tetrahydroaltersolanols C-F (1-4) and dihydroaltersolanol A (5), and five new alterporriol-type anthranoid dimers, alterporriols N-R (12-16), along with seven known analogues (6-11 and 17), were isolated from the culture broth and the mycelia of Alternaria sp. ZJ-2008003, a fungus obtained from a Sarcophyton sp. soft coral collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods including 1D and 2D NOE spectra as well as single-crystal X-ray crystallography. Compound 13 represents the first isolated alterporriol dimer with a C-4-C-4' linkage, and the absolute configuration of 4 was determined using the modified Mosher's method. Compounds 1 and 15 exhibited antiviral activity against the porcine reproductive and respiratory syndrome virus (PRRSV), with IC₅₀ values of 65 and 39 μM, respectively. Compound 14 showed cytotoxic activity against PC-3 and HCT-116 cell lines, with IC₅₀ values of 6.4 and 8.6 μM, respectively.

Four new bisabolane-type sesquiterpenoids, aspergiterpenoid A (1), (−)-sydonol (2), (−)-sydonic acid (3), and (−)-5-(hydroxymethyl)-2-(2′,6′,6′-trimethyltetrahydro-2H- pyran-2-yl)phenol (4) together with one known fungal metabolite (5) were isolated from the fermentation broth of a marine-derived fungus Aspergillus sp., which was isolated from the sponge Xestospongia testudinaria collected from the South China Sea. Four of them (1–4) are optically active compounds. Their structures and absolute configurations were elucidated by using NMR spectroscopic techniques and mass spectrometric analysis, and by comparing their optical rotations with those related known analogues. Compounds 1–5 showed selective antibacterial activity against eight bacterial strains with the MIC (minimum inhibiting concentrations) values between 1.25 and 20.0 µM. The cytotoxic, antifouling, and acetylcholinesterase inhibitory activities of these compounds were also examined.

Three new phenolic bisabolane sesquiterpenoid dimers, disydonols A-C (1-3), and one known compound (S)-(+)-sydonol (4) were isolated from the fermentation broth of a marine-derived fungus Aspergillus sp., which was isolated from the sponge Xestospongia testudinaria collected from the South China Sea. Their structures were elucidated on the basis of comprehensive spectral analysis including 1D and 2D NMR spectra and HR-ESI-MS. These compounds were evaluated for cytotoxic activity against HepG-2 and Caski human tumour cell lines. Among them, compounds 1 and 3 exhibited cytotoxicity against the two cell lines.

The Pere David's deer is a highly inbred, but recovered, species, making it interesting to consider their adaptive molecular evolution from an immunological perspective. Prior to this study, genomic sequencing was the only method for isolating all functional MHC genes within a certain species. Here, we report a novel protocol for isolating MHC class II loci from a species, and its use to investigate the adaptive evolution of this endangered deer at the level of multi-locus haplotypes. This protocol was designated “HURRAH” based on its various steps and used to estimate the total number of MHC class II loci. We confirmed the validity of this novel protocol in the giant panda and then used it to examine the Pere David's deer. Our results revealed that the Pere David's deer possesses nine MHC class II loci and therefore has more functional MHC class II loci than the eight genome-sequenced mammals for which full MHC data are currently available. This could potentially account at least in part for the strong survival ability of this species in the face of severe bottlenecking. The results from the HURRAH protocol also revealed that: (1) All of the identified MHC class II loci were monomorphic at their antigen-binding regions, although DRA was dimorphic at its cytoplasmic tail; and (2) these genes constituted two asymmetric functional MHC class II multi-locus haplotypes: DRA1*01 ~ DRB1 ~ DRB3 ~ DQA1 ~ DQB2 (H1) and DRA1*02 ~ DRB2 ~ DRB4 ~ DQA2 ~ DQB1 (H2). The latter finding indicates that the current members of the deer species have lost the powerful ancestral MHC class II haplotypes of nine or more loci, and have instead fixed two relatively weak haplotypes containing five genes. As a result, the Pere David's deer are currently at risk for increased susceptibility to infectious pathogens.

Ample variations of the major histocompatibility complex (MHC) genes are essential for vertebrates to adapt to various environmental conditions. In this study, we investigated the genetic variations and evolutionary patterns of seven functional MHC class II genes (one DRA, two DRB, two DQA, and two DQB) of the giant panda. The results showed the presence of two monomorphic loci (DRA and DQB2) and five polymorphic loci with different numbers of alleles (seven at DRB1, six at DRB3, seven at DQA1, four at DQA2, six at DQB1). The presence of balancing selection in the giant panda was supported by the following pieces of evidence: (1) The observed heterozygosity was higher than expected. (2) Amino acid heterozygosity was significantly higher at antigen-binding sites (ABS) compared with non-ABS sequences. (3) The selection parameter ω (dN/dS) was significantly higher at ABS compared with non-ABS sequences. (4) Approximately 95.45% of the positively selected codons (P>0.95) were located at or adjacent to an ABS. Furthermore, this study showed that (1) The Qinling subspecies exhibited high ω values across each locus (all >1), supporting its extensive positive selection. (2) The Sichuan subspecies displayed small ω at DRB1 (ω

Improved resistive switching memory characteristics by controlling the formation polarity in an IrOx/Al2O3/IrOx-ND/Al2O3/WOx/W structure have been investigated. High density of 1 × 1013/cm2 and small size of 1.3 nm in diameter of the IrOx nano-dots (NDs) have been observed by high-resolution transmission electron microscopy. The IrOx-NDs, Al2O3, and WOx layers are confirmed by X-ray photo-electron spectroscopy. Capacitance-voltage hysteresis characteristics show higher charge-trapping density in the IrOx-ND memory as compared to the pure Al2O3 devices. This suggests that the IrOx-ND device has more defect sites than that of the pure Al2O3 devices. Stable resistive switching characteristics under positive formation polarity on the IrOx electrode are observed, and the conducting filament is controlled by oxygen ion migration toward the Al2O3/IrOx top electrode interface. The switching mechanism is explained schematically based on our resistive switching parameters. The resistive switching random access memory (ReRAM) devices under positive formation polarity have an applicable resistance ratio of > 10 after extrapolation of 10 years data retention at 85°C and a long read endurance of 105 cycles. A large memory size of > 60 Tbit/sq in. can be realized in future for ReRAM device application. This study is not only important for improving the resistive switching memory performance but also help design other nanoscale high-density nonvolatile memory in future.

Artificial breeding is an important project to protect, recover and reintroduce endangered species. Knowledge of the population’s genetic diversity at functional loci is important for the establishment of effective captive breeding programs. The major histocompatibility complex (MHC) genes are ideal candidate genetic markers to inform planned breeding, due to their high levels of polymorphism and importance in the main immune coding region of the vertebrate genome. In this study, we constructed BAC-based contigs and isolated six functional MHC class I genes from the giant panda (Ailuropoda melanoleuca), which we designated Aime-C, Aime-F, Aime-I, Aime-K, Aime-L and Aime-1906. Analyses of the tissue expression patterns and full-length cDNA sequences of these class I genes revealed that Aime-C, -F, -I and -L could be considered classical class I loci, due to their extensive expression patterns and normal exonic structures. In contrast, Aime-K and -1906 appeared to be nonclassical genes based on their tissue-specific expression patterns and the presence of an abnormal exon 7 in both genes. We established techniques for genotyping exons 2 and 3 of the classical loci using locus-specific single strand conformation polymorphism (SSCP) and sequence analysis. In the Chengdu captive population, we identified one monomorphic locus (Aime-F) and three polymorphic loci with different numbers of alleles (4/4/4 exon 2 alleles at Aime-C/I/L and 6/5/5 exon 3 alleles at Aime-C/I/L). The distributions of the Aime-C, -I and -L alleles among members of different families were in good agreement with the known pedigree relationships, suggesting that the genotyping results are reliable. Therefore, the MHC-I genotyping techniques established in this study may provide a powerful tool for the future design of scientific breeding or release/reintroduction programs.

Enhanced resistive switching phenomena of IrO x /GdO x /W cross-point memory devices have been observed as compared to the via-hole devices. The as-deposited Gd2O3 films with a thickness of approximately 15 nm show polycrystalline that is observed using high-resolution transmission electron microscope. Via-hole memory device shows bipolar resistive switching phenomena with a large formation voltage of -6.4 V and high operation current of >1 mA, while the cross-point memory device shows also bipolar resistive switching with low-voltage format of +2 V and self-compliance operation current of x /GdO x interface, owing to oxygen ion migration. The oxygen-rich GdO x layer formation at the IrO x /GdO x interface will also help control the resistive switching characteristics. This cross-point memory device has also Repeatable 100 DC switching cycles, narrow distribution of LRS/HRS, excellent pulse endurance of >10,000 in every cycle, and good data retention of >104 s. This memory device has great potential for future nanoscale high-density non-volatile memory applications.