90 research outputs found
Fabrication and Optical Behaviors of Core–Shell ZnS Nanostructures
Novel core–shell nanostructures comprised of cubic sphalerite and hexagonal wurtzite ZnS have been synthesized at 150°C by a simple hydrothermal method. The results of HR-TEM and SAED investigation reveal that the cores of hexagonal wurtzite ZnS (ca. 200 nm in average diameter) are encapsulated by a shell of cubic sphalerite ZnS. The FE-SEM image of the nanomaterials shows a surface tightly packed with nanoparticles (<10 nm in size). The optical properties of the fabricated material have been studied in terms of ultraviolet–visible absorption and photoluminescence. Furthermore, a possible mechanism for the fabrication of the core–shell nanostructures has been presented
Effects of intra-aortic balloon pump on cerebral blood flow during peripheral venoarterial extracorporeal membrane oxygenation support
BACKGROUND: The addition of an intra-aortic balloon pump (IABP) during peripheral venoarterial extracorporeal membrane oxygenation (VA ECMO) support has been shown to improve coronary bypass graft flows and cardiac function in refractory cardiogenic shock after cardiac surgery. The purpose of this study was to evaluate the impact of additional IABP support on the cerebral blood flow (CBF) in patients with peripheral VA ECMO following cardiac procedures. METHODS: Twelve patients (mean age 60.40 ± 9.80 years) received VA ECMO combined with IABP support for postcardiotomy cardiogenic shock after coronary artery bypass grafting. The mean CBF in the bilateral middle cerebral arteries was measured with and without IABP counterpulsation by transcranial Doppler. The patients provided their control values. The mean CBF data were divided into two groups (pulsatile pressure greater than 10 mmHg, P group; pulsatile pressure less than 10 mmHg, N group) based on whether the patients experienced cardiac stun. The mean cerebral blood flow in VA ECMO (IABP turned off) alone and VA ECMO with IABP support were compared using the paired t test. RESULTS: All of the patients were successfully weaned from VA ECMO, and eight patients survived to discharge. The addition of IABP to VA ECMO did not change the mean CBF (251.47 ± 79.28 ml/min vs. 251.30 ± 79.47 ml/min, P = 0.96). The mean CBF was higher in VA ECMO alone than in VA ECMO combined with IABP support in the N group (257.68 ± 97.21 ml/min vs. 239.47 ± 95.60, P = 0.00). The addition of IABP to VA ECMO support increased the mean CBF values significantly compared with VA ECMO alone (261.68 ± 82.45 ml/min vs. 244.43 ± 45.85 ml/min, P = 0.00) in the P group. CONCLUSION: These results demonstrate that an IABP significantly changes the CBF during peripheral VA ECMO, depending on the antegrade blood flow by spontaneous cardiac function. The addition of an IABP to VA ECMO support decreased the CBF during cardiac stun, and it increased CBF without cardiac stun
III–V Nanowires: Synthesis, Property Manipulations, and Device Applications
III–V semiconductor nanowire (NW) materials possess a combination of fascinating properties, including their tunable direct bandgap, high carrier mobility, excellent mechanical flexibility, and extraordinarily large surface-to-volume ratio, making them superior candidates for next generation electronics, photonics, and sensors, even possibly on flexible substrates. Understanding the synthesis, property manipulation, and device integration of these III–V NW materials is therefore crucial for their practical implementations. In this review, we present a comprehensive overview of the recent development in III–V NWs with the focus on their cost-effective synthesis, corresponding property control, and the relevant low-operating-power device applications. We will first introduce the synthesis methods and growth mechanisms of III–V NWs, emphasizing the low-cost solid-source chemical vapor deposition (SSCVD) technique, and then discuss the physical properties of III–V NWs with special attention on their dependences on several typical factors including the choice of catalysts, NW diameters, surface roughness, and surface decorations. After that, we present several different examples in the area of high-performance photovoltaics and low-power electronic circuit prototypes to further demonstrate the potential applications of these NW materials. Towards the end, we also make some remarks on the progress made and challenges remaining in the III–V NW research field
Improved performance of InSe field-effect transistors by channel encapsulation
Due to the high electron mobility and photo-responsivity, InSe is considered as an excellent candidate for next generation electronics and optoelectronics. In particular, in contrast to many high-mobility two-dimensional (2D) materials, such as phosphorene, InSe is more resilient to oxidation in air. Nevertheless, its implementation in future applications requires encapsulation techniques to prevent the adsorption of gas molecules on its surface. In this work, we use a common lithography resist, poly (methyl methacrylate) (PMMA) to encapsulate InSe-based field-effect transistors (FETs). The encapsulation of InSe by PMMA improves the electrical stability of the FETs under a gate bias stress, and increases both the drain current and electron mobility. These findings indicate the effectiveness of the PMMA encapsulation method, which could be applied to other 2D materials
Controllable Synthesis of Single-Crystalline CdO and Cd(OH)2Nanowires by a Simple Hydrothermal Approach
Single-crystalline Cd(OH)2 or CdO nanowires can be selectively synthesized at 150 °C by a simple hydrothermal method using aqueous Cd(NO3)2 as precursor. The method is biosafe, and compared to the conventional oil-water surfactant approach, more environmental-benign. As revealed by the XRD results, CdO or Cd(OH)2 nanowires can be generated in high purity by varying the time of synthesis. The results of FESEM and HRTEM analysis show that the CdO nanowires are formed in bundles. Over the CdO-nanowire bundles, photoluminescence at ~517 nm attributable to near band-edge emission of CdO was recorded. Based on the experimental results, a possible growth mechanism of the products is proposed
Psoriasis Regression Analysis of MHC Loci Identifies Shared Genetic Variants with Vitiligo
Psoriasis is a common inflammatory skin disease with genetic components of both immune system and the epidermis. PSOR1 locus (6q21) has been strongly associated with psoriasis; however, it is difficult to identify additional independent association due to strong linkage disequilibrium in the MHC region. We performed stepwise regression analyses of more than 3,000 SNPs in the MHC region genotyped using Human 610-Quad (Illumina) in 1,139 cases with psoriasis and 1,132 controls of Han Chinese population to search for additional independent association. With four regression models obtained, two SNPs rs9468925 in HLA-C/HLA-B and rs2858881 in HLA-DQA2 were repeatedly selected in all models, suggesting that multiple loci outside PSOR1 locus were associated with psoriasis. More importantly we find that rs9468925 in HLA-C/HLA-B is associated with both psoriasis and vitiligo, providing first important evidence that two major skin diseases share a common genetic locus in the MHC, and a basis for elucidating the molecular mechanism of skin disorders
Preliminary Report on the Successful Breeding of the Endangered Fish Sinocyclocheilus grahami Endemic to Dianchi Lake
The fish Sinocyclocheilus grahami is one of the indicative and endemic
species in the Dianchi Lake eco-system. As a result of pollution and
invasion of exotic fishes, the fish had disappeared from Dianchi Lake
since 1986 and only a few small populations survive in springs and
streams around the lake. Due to the endangered status and special
scientific value, S. grahami was listed as the second class protective
animal of China in 1989. The importance of S. grahami and the
indigenous biodiversity of Dianchi Lake were recognized by the Global
Environment Foundation (GEF) /World Bank and Yunnan Development &
Reform Committee. Therefore a special grant was set up to restore and
conserve the indigenous biodiversity of Dianchi Lake. The artificial
breeding of S. grahami is a part of the targeted activities. Two
successful breeding experiments were achieved using five females plus
six males up to early March 2007. Approximately 1 600 eggs were
collected, of which 1 320 eggs fertilized using the dry-fertilizing
method. The mean fertilization rate was 73%. Approximately 480 fish fry
was hatched and the mean hatching rate was 36%. After 10 days of
cultivation, 95% fingerlings survived and their body lengths were up to
8-12 mm. The importance of the artificial breeding success of S.
grahami could be summarized as following: effectively protecting the
fish from extinction; releasing the fish fry back to appropriate water
body of the lake could help to restore the indigenous biodiversity of
Dianchi Lake; facilitating the shift of local fish cultivation from the
present non-indigenous to the future indigenous fishery
Artificial Propagation and Larvae Cultivation of Sinocyclocheilus tingi
The Fuxian golden line ( Sinocyclocheilus tingi ) is a famous fish
endemic to Fuxian Lake. From March to April 2009, four breeding
experiments were undertaken. 40 females and 20 males were injected with
hormones. 19 females and 15 males bred successfully, accounting for
47.5% of females and 75.0% of males. A total of 25 547 eggs were
obtained and subjected to dry-fertilization, with 16 810 eggs being
fertilized with a 65.8% success rate. 6 040 larvae were obtained with a
23.6% hatching rate. 3 056 larvae survived 20 days of cultivation with
a 50.6% survival rate. Reproductive dysfunctions are major constraining
factors to low Induced spawning of S. tingi in a captive environment.
Artificial conditions that did not reflect the necessary natural
environment of the fish may have also been a factor. This paper also
addresses the issue of massive larvae mortality. Determining the
constraints of artificial propagation is critical to the transfer of
this species into cultivation fish. The presented success in
propagation of S. tingi will contribute to understanding its biology
and protection from extinction
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