Efficient Carrier Transport in 2D Bi2O2Se/CsBi3I10 Perovskite Heterojunction Enables Highly-Sensitive Broadband Photodetection.

2D Bi2O2Se has recently garnered significant attention in the electronics and optoelectronics fields due to its remarkable photosensitivity, broad spectral absorption, and excellent long-term environmental stability. However, the development of integrated Bi2O2Se photodetector with high performance and low-power consumption is limited by material synthesis method and the inherent high carrier concentration of Bi2O2Se. Here, a type-I heterojunction is presented, comprising 2D Bi2O2Se and lead-free bismuth perovskite CsBi3I10, for fast response and broadband detection. Through effective charge transfer and strong coupling effect at the interfaces of Bi2O2Se and CsBi3I10, the response time is accelerated to 4.1 µs, and the detection range is expanded from ultraviolet to near-infrared spectral regions (365-1500 nm). The as-fabricated photodetector exhibits a responsivity of 48.63 AW-1 and a detectivity of 1.22×1012 Jones at 808 nm. Moreover, efficient modulation of the dominant photocurrent generation mechanism from photoconductive to photogating effect leads to sensitive response exceeding 103 AW-1 for heterojunction-based photo field effect transistor (photo-FETs). Utilizing the large-scale growth of both Bi2O2Se and CsBi3I10, the as-fabricated integrated photodetector array demonstrates outstanding homogeneity and stability of photo-response performance. The proposed 2D Bi2O2Se/CsBi3I10 perovskite heterojunction holds promising prospects for the future-generation photodetector arrays and integrated optoelectronic systems.

Controlled Growth of Large-Sized and Phase-Selectivity 2D GaTe Crystals.

GaTe has recently attracted significant interest due to its direct bandgap and unique phase structure, which makes it a good candidate for optoelectronics. However, the controllable growth of large-sized monolayer and few-layer GaTe with tunable phase structures remains a great challenge. Here the controlled growth of large-sized GaTe with high quality, chemical uniformity, and good reproducibility is achieved through liquid-metal-assisted chemical vapor deposition method. By using liquid Ga, the rapid growth of 2D GaTe flakes with high phase-selectivity can be obtained due to its reduced reaction temperature. In addition, the method is used to synthesize many Ga-based 2D materials and their alloys, showing good universality. Raman spectra suggest that the as-grown GaTe own a relatively weak van der Waals interaction, where monoclinic GaTe displays highly-anisotropic optical properties. Furthermore, a p-n junction photodetector is fabricated using GaTe as a p-type semiconductor and 2D MoSe2 as a typical n-type semiconductor. The GaTe/MoSe2 heterostructure photodetector exhibits large photoresponsivity of 671.52 A W-1 and high photo-detectivity of 1.48 × 1010 Jones under illumination, owing to the enhanced light absorption and good quality of as-grown GaTe. These results indicate that 2D GaTe is a promising candidate for electronic and photoelectronic devices.

High-performance mesoporous γ-Fe2O3 sphere/graphene aerogel composites towards enhanced lithium storage.

Transition metal oxides have recently been demonstrated as highly attractive anodes for high-capacity lithium ion batteries, whose electrochemical properties could be further improved through rational architecture design and incorporating reliable conductive network. Herein, mesoporous γ-Fe2O3 spheres/graphene aerogel composites were synthesized via a solvothermal pathway followed by suitable annealing. Experimental results reveal the uniform mesoporous structure and well-dispersed γ-Fe2O3 spheres with the size of 300-400 nm embedded in the mesopores of the graphene aerogel network. Compared with α-Fe2O3/graphene aerogel and pure γ-Fe2O3, the as-synthesized composite delivers, at the first cycle, a high discharging capacity of 1080 mAh g-1 at current density of 200 mA g-1. Even at much higher current density of 8000 mA g-1, satisfactory discharging capacities of 421.5 mAh g-1 can still be achieved. Upon 100 charging-discharging cycles, the specific capacity of as high as 890.5 mAh g-1 at 200 mA g-1 is maintained. The enhanced electrochemical properties could be attributed to their favorable three-dimensional graphene aerogel network, which accounts for the improved structural stability and electronic conductivity of γ-Fe2O3 during the lithiation/delithiation process.

Enhanced Transmission and Self-Cleaning of Patterned Sapphire Substrates Prepared by Wet Chemical Etching Using Silica Masks.

Highly transparent and superhydrophilic sapphire with surface antireflective subwavelength structures were prepared by wet etching using colloidal monolayer silica masks. The film thicknesses of the silica masks were adjusted by the volume concentrations of polystyrene spheres. The evolution of etching morphologies of sapphire was studied, and antireflective concave pyramid nanoarrays on sapphire substrates were designed by calculation and were then prepared. The transmission and wettability of as-obtained patterned sapphire substrates were also investigated. As for sapphire with optimum surface concave micropyramid arrays, average visible transmittance can reach 91.7%, which is apparently higher than that of flat sapphire (85.5%). Moreover, the concave pyramid arrays can significantly increase the surface hydrophilicity of sapphire, exhibiting a water contact angle of 12.6° compared with 62.7° of flat sapphire. The proposed method can be an excellent strategy for preparing antireflective and self-cleaning concave micropyramid subwavelength structures on sapphire without complicated equipment and expensive raw materials.

Broad-band anti-reflective pore-like sub-wavelength surface nanostructures on sapphire for optical windows.

Compared with conventional anti-reflective film, an anti-reflective sub-wavelength surface structure provides an ideal choice for a sapphire optical window especially in harsh environments. However, it is still a challenge to obtain a sapphire anti-reflective surface microstructure because of its high hardness and chemical inertness. In this paper, combined with optical simulation, we proposed a facile method based on the anodic oxidation of aluminum film and following epitaxial annealing. Al thin film was deposited on a sapphire substrate by magnetron sputtering, and anodic oxidation was then performed to prepare surface pore-like structures on the Al film. Followed by two-step annealing, both the anodic oxidized coating and underlying unoxidized Al film were transformed totally into alumina. The parameters of anodic oxidation were analyzed to obtain the optimal pore-like structures for the antireflection in the mid-infrared and visible spectrum regions, respectively. Finally, the optimized surface sub-wavelength nanostructure on sapphire can increase the transmittance by 7% in the wavelength range of 3000-5000 nm and can increase 13.2% significantly for visible spectrum region, respectively. Meanwhile, the surface wettability can be also manipulated effectively. The preparation of surface pore-like sub-wavelength structure by the annealing of anodic oxidized aluminum film on sapphire is a feasible, economical and convenient approach and can find the applications for various optoelectronic fields.

A retrospective study of the efficacy and safety of levofloxacin in children with severe infection.

Objectives: Levofloxacin is widely used because of its broad-spectrum antimicrobial activity and convenient dosing schedule. However, the relevance of its use in children remains to be investigated. The purpose of this study is to investigate the efficacy and safety of levofloxacin use in children with severe infections. Methods: We conducted a retrospective observational study of patients <18 years of age who received levofloxacin intravenously in the Pediatric Intensive Care Unit (PICU) of our hospital during the period between 2021 and 2022. Patient demographics, course characteristics, clinical effectiveness, and adverse event correlations were extracted through a retrospective tabular review. Results: We included 25 patients treated with 28 courses of levofloxacin. The mean age of these children treated with levofloxacin was 4.41 years. Conversion of pathogenic microbiological test results to negative after levofloxacin treatment was detected in 11 courses (39.29%). A decrease in inflammatory markers, white blood cell or C-reactive protein counts, was detected in 18 courses (64.29%). A total of 57 adverse events occurred during the treatment period, of which 21 were possibly related to levofloxacin and no adverse events were probably related to levofloxacin. Conclusion: The effectiveness of levofloxacin use in children with serious infections is promising, especially for the treatment of multidrug-resistant bacteria. Adverse events occurring during the initiation of levofloxacin therapy in children are reported to be relatively common, but in this study, only a small percentage of them were possibly related to levofloxacin, and none of them were highly possibly related to levofloxacin.

Plasma metagenomics reveals regional variations of emerging and re-emerging pathogens in Chinese blood donors with an emphasis on human parvovirus B19.

At present, many infectious pathogens, especially emerging/re-emerging pathogens, exist in the blood of voluntary blood donors and may be transmitted through blood transfusions. However, most of Chinese blood centers only routinely screen for HBV, HCV, HIV, and syphilis. We employed metagenomic next-generation sequencing (mNGS) to investigate the microbiome in healthy voluntary blood donors to help assess blood safety in China by identifying infectious pathogens presented in donations that could lead to transfusion-acquired infections. We collected 10,720 plasma samples from voluntary blood donors from seven blood centers in different cities during 2012-2018 in China. A total of 562 GB of clean data was obtained. By analyzing the sequencing data, it was found that the most commonly identified bacteria found in the healthy blood were Serratia spp. (5.0176%), Pseudomonas spp. (0.6637%), and Burkholderia spp. (0.5544%). The principal eukaryote were Leishmania spp (1.3723%), Toxoplasma gondii (0.6352%), and Candida dubliniensis (0.1848%). Among viruses, Human Parvovirus B19 (B19V) accounts for the highest proportion (0.1490%), followed by Torque teno midi virus (0.0032%) and Torque teno virus (0.0015%). Since that B19V is a non-negligible threat to blood safety, we evaluated the positive samples for B19V tested by mNGS using quantitative polymerase chain reaction, Sanger sequencing, and phylogenetic analysis to achieve a better understanding of B19V in Chinese blood donors. Subsequently, 9 (0.07%) donations were positive for B19V DNA. The quantitative DNA levels ranged from 5.58 × 102 to 7.24 × 104 IU/ml. The phylogenic analyses showed that prevalent genotypes belonged to the B19-1A subtype, which disclosed previously unknown regional variability in the B19V positivity rate. The investigation revealed that many microbes dwell in the blood of healthy donors, including some pathogens that may be dormant in the blood and only cause disease under specific conditions. Thus, investigating the range and nature of potential pathogens in the qualified donations provided a framework for targeted interventions to help prevent emerging and re-emerging infectious diseases.

Hepatitis B surface antigen variants in voluntary blood donors in Nanjing, China.

BACKGROUND: Hepatitis B virus (HBV) is still one of the serious infectious risks for the blood transfusion safety in China. One plausible reason is the emergence of the variants in the major antigenic alpha determinant within the major hydrophilic region (MHR) of hepatitis B surface antigen (HBsAg), which have been assumed to evade the immune surveillance and pose a challenge to the disease diagnosis. It is well documented that some commercial ELISA kits could detect the wild-type but not the mutant viruses. The high prevalence of HBV in China also impaired the application of nucleic acid testing (NAT) in the improvement of blood security. Molecular epidemiological study of HBsAg variations in China is still limited. This study was designed to identify the prevalence of mutations in the HBsAg in voluntary blood donors in Nanjing, China. METHODS: A total of 20,326 blood units were enrolled in this study, 39 donors were positive for HBV S gene in the nested-PCR. Mutations in the major hydrophilic region (MHR; aa 99-169) were identified by direct sequencing of S region. RESULTS: Among of 20,326 blood units in the Red Cross Transfusion Center of Nanjing from October 2008 to April 2009, 296 samples (1.46%, 296/20,326) were HBsAg positive in the 2 successive rounds of the ELISA test. In these HBsAg positive units, HBV S gene could be successfully amplified from 39 donors (13.18%, 39/296) in the nested-PCR. Sequence analysis revealed that 32 strains (82.1%, 32/39) belong to genotype B, 7 strains (17.9%, 7/39) to genotype C. Besides well known G145R, widely dispersed variations in the MHR of S region, were observed in 20 samples of all the strains sequenced. CONCLUSIONS: HBV/B and HBV/C are dominant in Nanjing, China. The mutations in the MHR of HBsAg associated with disease diagnosis are common.

[Effect of technological parameters of sputtering on the microstructure of silicon film investigated by Raman analysis].

In order to facilitate optical polishing of silicon carbide space telescope, in the present paper, silicon film, which has similar coefficient of thermal expansion with silicon carbide, was fabricated on SiC substrate by radio frequency magnetron sputtering. The effect of substrate temperature, radio frequency power, and substrate bias voltage was investigated by Raman scattering. The results indicate that at lower substrate temperature, the crystalline volume fraction of Si films increases with the increase in deposition temperature. Exceeding a certain temperature, the crystalline volume fraction decreases with further increasing deposition temperature; the increase in substrate bias voltage is bad for forming crystalline structure; the effect of radio power on microstructure of silicon film is comparatively complicated. As the rf power increases, the cluster size and crystallite volume fraction decrease, and both of them increase with further increasing the rf power. But when the rf power is too high, the crystallite volume fraction of the silicon film will decrease slightly.

Selenium-rich nickel cobalt bimetallic selenides with core-shell architecture enable superior hybrid energy storage devices.

The continuous exploration of advanced electrode materials is of remarkable significance to revolutionize next-generation high-performance energy storage devices towards a green future. Benefiting from their electrochemically active sites and abundant redox centers, bimetallic selenides with desirable nanostructures recently have emerged as promising electrode alternatives for battery-supercapacitor hybrid (BSH) devices which demonstrate enormous potential in bridging the gap between electrochemical properties with high power densities (supercapacitors) and energy densities (batteries). Herein, employing the hydrothermal approach with solid Ni-Co spheres as precursors followed by the selenization process, selenide-rich bimetallic selenide spheres with a core-shell nanostructure were rationally designed and synthesized for use as the cathode electrode in superior BSH devices. The as-obtained (NiCo)9Se8/(NiCo)0.85Se (Ni-Co-Se) exhibits a high specific capacity of 164.44 mA h g-1 at a current density of 1 A g-1 with 85.72% capacity retention even after 5000 cycles at a current density of as high as 8 A g-1, suggesting its great promise in practical applications for BSH devices. By integrating activated carbon as the anode with the as-obtained bimetallic selenides as the cathode, an alkaline aqueous BSH device is fabricated and delivers a high energy density of 37.54 W h kg-1 at a high power density of 842.7 W kg-1. It is found that the excellent electrochemical performances can be ascribed to facile ion and electron transport pathways, high electrical conductivity and reliable structural robustness of the prepared selenides. Moreover, the synthetic strategy presented in this paper opens up an avenue to guide the synthesis of various anion doped bimetallic compounds towards high-performance energy conversion and storage devices.

Self-templated formation of (NiCo)9S8 yolk-shelled spheres for high-performance hybrid supercapacitors.

Rational materials design for the synthesis of desirable hollow micro- and nanostructures has recently revealed the remarkable potential for high-performance energy storage and conversion devices. Owing to their unique "core-void-shell" structural configurations, yolk-shell-structured electrode materials can achieve intimate contact with the electrolyte and alleviate the volume expansion issue during electrochemical cycling, which is therefore poised to further boost the electrochemical properties of hybrid supercapacitors. Herein, a facile self-templated strategy, consisting of a hydrothermal step and a high-temperature sulfurization process, has been developed for the construction of yolk-shell (NiCo)9S8 spheres in situ coated by graphite carbon ((NiCo)9S8/GC) due to the non-equilibrium thermal treatment of alkali metal alkoxides. The as-synthesized yolk-shelled sphere exhibits a high specific capacitance of 1434.4 F g-1 (179.3 mA h g-1) at a current density of 1 A g-1, and good rate capability and cycling stability with 83.1% capacitance retention at 8 A g-1 over 5000 cycles. To further demonstrate its practical application, a hybrid supercapacitor device was assembled using (NiCo)9S8/GC as the battery-type positive electrode and activated carbon (AC) as the capacitive-type electrode. The as-fabricated device can reach a wide voltage window of up to 1.6 V, deliver a high energy density of 55.6 W h kg-1 at a power density of 800.3 W kg-1 and maintain 90.2% of specific capacitance after 3000 cycles.

Comparison of cyanobacterial communities in temperate deserts: A cue for artificial inoculation of biological soil crusts.

The topsoil cyanobacteria in biological soil crusts (BSCs) play a vital role in stabilizing soil surface of disturbed habitats in water and nutrient-poor ecosystems. Currently, artificial inoculation of BSCs is considered as an effective approach to restore habitats and accelerate ecosystem regeneration. Understanding the character of cyanobacterial communities is the necessary prerequisite to explore the artificial inoculation of BSCs. For this reason, cyanobacterial communities in BSCs were compared between two mid-latitute temperate deserts with distinct precipitation patterns. The results showed that Oscillatoriales and Nostocales dominated crusts in the Tengger desert with majority of rainfall in summer and early autumn while Oscillatoriales dominated crusts in the Kyzyl kum desert with more rainfall in winter and early spring. Moreover, filamentous Microcoleus vaginatus overwhelmingly dominated all the crusts in both deserts with Mastigocladopsis sp. and Chroococcidiopsis spp. as the dominant heterocystous cyanobacteria. Of note, genus Wilmottia kept a relative stable and high abundance in both deserts. The top two abundantly shared cyanobacteria (> 1% of total sequences) were M. vaginatus and Mastigocladopsis sp. in both deserts, while 16 genera with significant variances were found between the two deserts (P <0.05). Total variations of cyanobacterial communities across the deserts were largely explained by a combination of biotic factors (microbial biomass C and N) and abiotic factors (soil pH, soil water content, soil water holding capacity, and soil available potassium). Compared to better-developed crusts, cyanobacterial abundance was higher in cyanobacterial crusts. BSC type and/or geographic location significantly affected cyanobacterial Shannon diversity without significantly influencing species richness. Our data suggest that the basic and major groups (e.g. M. vaginatus, Wilmottia spp., Mastigocladopsis sp., and Chroococcidiopsis spp.), and the abundantly shared phylotypes which showed significant difference in cyanobacterial communities between deserts, should be focused on to further explore the artificial inoculation of BSCs in temperate drylands.

[XPS and Raman spectral analysis of nitrogenated tetrahedral amorphous carbon (ta-C : N) films with different nitrogen content].

Nitrogenated tetrahedral amorphous carbon (ta-C : N) films were prepared on the polished C--Si substrates by introducing highly pure nitrogen gas into the cathode region and the depositing chamber synchronously using filtered cathodic vacuum arc (FCVA) technology. The nitrogen content in the films was controlled by changing the flow rate of nitrogen gas. The configuration of ta-C : N films was investigated by means of X-ray photoelectron spectroscopy (XPS) and visible Raman spectroscopy. It was shown that the nitrogen content in the films increased from 0.84 at% to 5.37 at% monotonously when the nitrogen flow rate was varied from 2 seem to 20 sccm. The peak position of C (1s) core level moved towards higher binding energy with the increase in nitrogen content. The shift of C (1s) peak position could be ascribed to the chemical bonding between carbon and nitrogen atoms even though more three-fold coordinated sp2 configuration as in graphite was formed when the films were doped with more nitrogen atoms. Additionally, the half width of C(1s) peak gradually was also broadened with increasing nitrogen content. In order to discover clearly the changing regularities of the microstructure of the films, the XPS C(1s) spectra and Raman spectra were deconvoluted using a Gaussian-Lorentzian mixed lineshape. It was shown that the tetrahedral hybridization component was still dominant even though the ratio of sp2/sp3 obtained from C(1s) spectra rose with the increase in nitrogen content. The Raman measurements demonstrated that the G peak position shifted towards higher frequency from 1,561 to 1,578 cm(-1) and the ratio of ID/IG also rose with the increase in nitrogen content. Both results indicated that the graphitizing tendency could occur with the increase in nitrogen content in the films.

Achieving Ultrahigh Capacity with Self-Assembled Ni(OH)2 Nanosheet-Decorated Hierarchical Flower-like MnCo2O4.5 Nanoneedles as Advanced Electrodes of Battery-Supercapacitor Hybrid Devices.

Self-assembled Ni(OH)2 nanosheet-decorated hierarchical flower-like MnCo2O4.5 nanoneedles were synthesized via a cost-effective and facile hydrothermal strategy, aiming to realize a high-capacity advanced electrode of a battery-supercapacitor hybrid (BSH) device. It is demonstrated that the as-synthesized hierarchical flower-like MnCo2O4.5@Ni(OH)2-nanosheet electrode exhibits a high specific capacity of 318 mAh g-1 at a current density of 3 A g-1 and still maintains a capacity of 263.5 mAh g-1 at a higher current density of 20 A g-1, with an extremely long cycle lifespan of 87.7% capacity retention after 5000 cycles. Moreover, using the unique core-shell structure as the cathode and hollow Fe2O3 nanoparticles/reduced graphene oxide as the anode, the BSH device delivers a high energy density of 56.53 Wh kg-1 when the power density reaches 1.9 kW kg-1, and there is an extraordinarily good cycling stability with the capacity retention rate of 90.4% after 3000 cycles. It is believed that the superior properties originate from desirable core-shell structures alleviating the impact of volume changes as well as the existence of two-dimensional Ni(OH)2 nanosheets with more active sites, thereby improving the cycle stability and achieving ultrahigh capacity. These results will provide more access to the rational material design of diverse nanostructures toward high-performance energy storage devices.

[Spectroscopic ellipsometry investigations of amorphous diamond films deposited with filtered arc].

In order to investigate thoroughly the optical properties of amorphous diamond (alpha-D) films deposited by the filtered vacuum arc technology, the optical constants of the films were measured by spectroscopic ellipsometry. Moreover, the dispersion relations of the optical constants, and the correlations among refractive index, extinction coefficient, optical gap and the substrate bias were also analyzed. It has been shown that the refractive index of alpha-D films is higher than that of diamond crystal, and the absorption edge corresponding to the interband transformation can be described with the parabolic line shape. With increasing the wavelength, the extinction coefficient gradually declines and approaches nearly to zero in the infrared band. In addition, the adjustable amplitudes of the optical constants owing to the changing bias also reduce strikingly with the extension of the wavelength. With raising the bias, the refractive index and the optical gap firstly augment, then minish, and there is a maximal value when the substrate bias is -80 V. However, the extinction coefficient firstly minishes, then augments, and there is a minimal value when the bias is -80 V.

[Analysis of water sources of plants in artificial sand-fixation vegetation area based on large rainfall events.] / 基于较大降水事件的人工固沙植被区植物水分来源分析.

Water is a major limiting factor for plant growth in arid and semi-arid regions. To find out the main sources of water for two artificial sand-fixation plants (Caragana korshinskii and Artemisia ordosica), we analyzed the characteristics of hydrogen and oxygen stable isotopes in water molecules of rainfall, soil water and xylem water. To analyze water sources of these two plants, we used a direct comparison method and a multi-variate mixed linear model. The results showed that an equation of local meteoric water line in Shapotou was δD=7.83δ18O+5.64 (R2=0.91). The value for rainfall δ18O varied during plant-growing season, which was higher in the beginning and end of growing season, and lower in the peak of growing season. The value for soil water δ18O in the upper layers changed dramatically. The change range became smaller in the deeper soil layer. C. korshinskii had a greater efficiency (56.1%) in utilizing soil water in 40-80 cm soil layer. A. ordosica had a utilizing efficiency of 56.4% in 20-60 cm soil layer. A week after rain event, C. korshinskii and A. ordosica showed a higher efficiency in upper soil water. C. korshinskii showed an increase of 12.5% in utilizing soil water in 0-40 cm soil layer and A. ordosicas showed an increase of 10% in utilizing soil water in 0-20 cm layer. These results suggested that C. korshinskii and A. ordosica changed their water use strategy after large rainfall events, which might enable them to more easily adapt to arid environment.

Helical growth of aluminum nitride: new insights into its growth habit from nanostructures to single crystals.

By understanding the growth mechanism of nanomaterials, the morphological features of nanostructures can be rationally controlled, thereby achieving the desired physical properties for specific applications. Herein, the growth habits of aluminum nitride (AlN) nanostructures and single crystals synthesized by an ultrahigh-temperature, catalyst-free, physical vapor transport process were investigated by transmission electron microscopy. The detailed structural characterizations strongly suggested that the growth of AlN nanostructures including AlN nanowires and nanohelixes follow a sequential and periodic rotation in the growth direction, which is independent of the size and shape of the material. Based on these experimental observations, an helical growth mechanism that may originate from the coeffect of the polar-surface and dislocation-driven growth is proposed, which offers a new insight into the related growth kinetics of low-dimensional AlN structures and will enable the rational design and synthesis of novel AlN nanostructures. Further, with the increase of temperature, the growth process of AlN grains followed the helical growth model.

Evaluation of clinical treatment of atrial fibrillation associated with rheumatic mitral valve disease by radiofrequency ablation.

OBJECTIVES: The aim of this clinical study was to evaluate the effectiveness and advantages of the radiofrequency ablation maze procedure in the treatment of atrial fibrillation associated with rheumatic mitral valve disease. METHODS: We developed one kind of modified Cox III maze procedure with the use of radiofrequency ablation in the treatment of atrial fibrillation associated with rheumatic mitral valve disease and compared the outcome of 96 patients of atrial fibrillation associated rheumatic mitral valve disease who underwent radiofrequency ablation maze procedure plus mitral valve replacement with that of 87 patients with atrial fibrillation associated rheumatic mitral valve disease who had mitral valve replacement during the same interval by the same surgeon. The patients in the two groups were similar in age, gender, preoperative New York Heart Association class and duration of preoperative atrial fibrillation. RESULTS: No operative deaths occurred in the study group and the control group. Duration of cardiopulmonary bypass (137.63 +/- 10.82 vs. 90.95 +/- 7.65 min, P<0.01) and duration of aortic crossclamping (56.96 +/- 6.19 vs. 32.66 +/- 3.55 min, P<0.01) were prolonged in the study group. Blood loss from chest tubes was similar in the two groups (494.06 +/- 100.44 vs. 476.09 +/- 115.84 ml, P=0.263). Freedom from atrial fibrillation in the study group was 77% 3 years after the operation compared with 25% in the control group (P<0.01). CONCLUSIONS: The addition of the radiofrequency ablation maze procedure to mitral valve replacement is safe and effective in the treatment of atrial fibrillation associated with rheumatic mitral valve disease.

Scale-dependent effects of habitat fragmentation on reproduction in the annual Circaeaster agristis, a narrow endemic and threatened species.

BACKGROUND: Habitat fragmentation and the resulting decline in population size and density commonly reduce the reproduction of rare and threatened species. We investigated the impacts of population size and density on reproduction in more than 30 populations of Circaeaster agristis, a narrow endemic and threatened species, in 2010 and 2011. We also examined the effects of NND (nearest neighbor distance) and LNS (local neighbor size), within radii of 0.1 m, 0.2 m and 0.3 m, on reproduction in two of the populations in 2011. RESULTS: Population size did not affect fruit (seed) number and fruit set in either year studied. Population density had an indirect negative effect on fruit number and fruit set as a consequence of a negative effect on plant size in 2010, but had no effect on fruit number and fruit set in 2011. Within populations, individual fruit number did not change, and individual fruit set increased independent of plant size, in response to increasing NND. Both individual fruit number and individual fruit set increased, independent of plant size, with increases in LNS within a 0.1 m radius, but did not change with increases in LNS within radii of between 0.1 m and 0.2 m radii or between 0.2 m and 0.3 m. CONCLUSIONS: The effect of habitat fragmentation on reproduction of C. agristis is scale-dependent. In contrast to the generally accepted idea that fragmentation reduces plant reproduction, reproductive success may increase in sparse populations or increase in response to decreases in LNS in C. agristis.

Large-scale fabrication of nanopatterned sapphire substrates by annealing of patterned Al thin films by soft UV-nanoimprint lithography.

Large-scale nanopatterned sapphire substrates were fabricated by annealing of patterned Al thin films. Patterned Al thin films were obtained by soft UV-nanoimprint lithography and reactive ion etching. The soft mold with 550-nm-wide lines separated by 250-nm space was composed of the toluene-diluted polydimethylsiloxane (PDMS) layer supported by the soft PDMS. Patterned Al thin films were subsequently subjected to dual-stage annealing due to the melting temperature of Al thin films (660°C). The first comprised a low-temperature oxidation anneal at 450°C for 24 h. This was followed by a high-temperature annealing in the range of 1,000°C and 1,200°C for 1 h to induce growth of the underlying sapphire single crystal to consume the oxide layer. The SEM results indicate that the patterns were retained on sapphire substrates after high-temperature annealing at less than 1,200°C. Finally, large-scale nanopatterned sapphire substrates were successfully fabricated by annealing of patterned Al thin films for 24 h at 450°C and 1 h at 1,000°C by soft UV-nanoimprint lithography.