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1.
ACS Appl Mater Interfaces ; 16(13): 16962-16972, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38520330

ABSTRACT

Typical methods for stable immobilization of proteins often involve time-consuming surface modification of silicon-based materials to enable specific binding, while the nonspecific adsorption method is faster but usually unstable. Herein, we fused a silica-binding protein, Si-tag, to target proteins so that the target proteins could attach directly to silica substrates in a single step, markedly streamlining the immobilization process. The adhesion force between the Si-tag and glass substrates was determined to be approximately 400-600 pN at the single-molecule level by atomic force microscopy, which is greater than the unfolding force of most proteins. The adhesion force of the Si-tag exhibits a slight increase when pulled from the C-terminus compared to that from the N-terminus. Furthermore, the Si-tag's adhesion force on a glass surface is marginally higher than that on a silicon nitride probe. The binding properties of the Si-tag are not obviously affected by environmental factors, including pH, salt concentration, and temperature. In addition, the macroscopic adhesion force between the Si-tag-coated hydrogel and glass substrates was ∼40 times higher than that of unmodified hydrogels. Therefore, the Si-tag, with its strong silica substrate binding ability, provides a useful tool as an excellent fusion tag for the rapid and mechanically robust immobilization of proteins on silica and for the surface coating of silica-binding materials.


Subject(s)
Carrier Proteins , Silicon Dioxide , Silicon Dioxide/chemistry , Spectrum Analysis , Microscopy, Atomic Force , Surface Properties
2.
Zhonghua Nan Ke Xue ; 27(3): 231-235, 2021 Mar.
Article in Chinese | MEDLINE | ID: mdl-34914305

ABSTRACT

OBJECTIVE: To investigate the clinical characteristics, diagnosis, treatment and etiology of persistent Müllerian duct syndrome (PMDS). METHODS: A 3-year-old boy was diagnosed with PMDS according to the clinical manifestations and the results of ultrasonography, laboratory examinations and earlier surgical examination. We performed genetic tests for the patient and his family members, removed the infantile uterus by laparoscopic wedge hysterectomy, biopsied and descended the bilateral testes, and ligated the bilateral internal rings, followed by a retrospective analysis and review of relevant literature. RESULTS: The operation was successful. Gonad biopsy revealed testis tissue, and PMDS was confirmed by intraoperative findings and related examinations. Good bilateral testicular blood supply was found during the 6-month follow-up after surgery. Medical exome sequencing showed the AMHR2 gene c.1499G > A (p.Cys500Tyr) mutant homozygote (A/A) in the patient and his sister and mutant heterozygote (G/A) in his parents. CONCLUSIONS: Laparoscopy is definitely effective for the treatment of PMDS. In surgery, the infantile uterus should be removed in case of good blood supply to the testis, and so were the bilateral testes if they cannot be descended. The homozygous mutation in the AMHR2 gene c. 1499G > A (p. Cys500Tyr) can lead to male PMDS. Pedigree investigation may provide some evidence for possible fertility in PMDS patients.


Subject(s)
Laparoscopy , Child, Preschool , Disorder of Sex Development, 46,XY , Humans , Male , Pedigree , Retrospective Studies
3.
World J Clin Cases ; 9(25): 7372-7380, 2021 Sep 06.
Article in English | MEDLINE | ID: mdl-34616804

ABSTRACT

BACKGROUND: Necrotizing enterocolitis (NEC) of the newborn is a frequently occurring clinical disease in infants. The mortality rate of NEC in premature infants is as high as 50%, and the morbidity rate is on the rise. NEC has already caused serious impacts on newborn survival and poses serious threats to both children and families. AIM: To investigate the expression and significance of mucin 1 (MUC1) and interleukin-11 (IL-11) in the intestinal mucosa of infants with neonatal NEC after surgery. METHODS: Forty-eight postoperative intestinal mucosal specimens from children with NEC (NEC group) and twenty-two intestinal mucosal specimens from children with congenital intestinal atresia (control group) were collected in our hospital. Immunohistochemical staining and Western blot analysis were used to examine the protein expression of MUC-1 and IL-11 in the two groups. The serum levels of tumor necrosis factor-α (TNF-α) and IL-1ß in the two groups were measured by enzyme-linked immunosorbent assay, and the relationship between MUC-1 and IL-11 protein expression and serum TNF-α and IL-1ß levels was analyzed by the linear correlation method. RESULTS: The protein expression of MUC-1 and IL-11 in the NEC group was significantly lower than that in the control group, and the difference was statistically significant (P < 0.05). The levels of serum TNF-α and IL-1ß in the NEC group were significantly higher than those in the control group (P < 0.05). The protein expression of MUC-1 and IL-11 in the NEC group negatively correlated with serum TNF-α and IL-1ß levels (P < 0.05). There was a significant negative correlation between the protein expression of MUC-1 and IL-11 and the levels of serum TNF-α and IL-1ß in the NEC group. CONCLUSION: The protein expression of MUC1 and IL-11 in the intestinal mucosa of children with NEC is significantly downregulated after surgery. This downregulation may be involved in the pathogenesis of this disease and has a certain correlation with inflammatory response factors in children with NEC.

4.
Phys Chem Chem Phys ; 22(16): 8672-8678, 2020 Apr 29.
Article in English | MEDLINE | ID: mdl-32270850

ABSTRACT

Electric control of magnetism by resistive switching is a simple and efficient approach to manipulate magnetism. However, the mechanism of magnetism manipulation by resistive switching is not well understood. Detailed characterization was performed to investigate the mechanism of magnetization changes with resistance state. We achieved a reversible and nonvolatile control of magnetization in a Co-Fe-Ta-B-O film at room temperature by resistive switching. It is found that a higher saturation magnetization could be attributed to the formation of a conducting filament rich in the reductive state of iron when the device is switched to low resistance. This work might provide a new insight to achieve magnetoelectric coupling.

5.
ACS Appl Mater Interfaces ; 11(46): 43344-43350, 2019 Nov 20.
Article in English | MEDLINE | ID: mdl-31659894

ABSTRACT

Memtransistor is a multiterminal device combining the concepts of memristor and field-effect transistor with two-dimensional (2D) materials. The gate tunability of resistive switching in 2D memtransistor enables the multifunctional modulation and promising applications in neuromorphic network. However, the tunability of switching ratio in 2D memtransistor remains small and seriously limits its practical application. Here, we investigate a memtransistor based on a 3-layer MoS2 and realize the electric, light, and their combined modulations. In the electric gate mode, switching ratio is tunable in a large scale in the range 100-105. In the light gate mode, a maximum conductance change of 450% can be obtained by increasing the light power. Moreover, the switching ratio can be further improved to ∼106 through a combination of electric and light dual gating. Such a gating effect can be ascribed to the modulation of carrier density in the MoS2 channel. Our work provides a simple approach for achieving a high-performance multifunctional memtransistor.

6.
ACS Omega ; 4(10): 14312-14316, 2019 Sep 03.
Article in English | MEDLINE | ID: mdl-31508556

ABSTRACT

Endotoxin is a highly toxic stimulator originated from the outer membrane of Gram-negative bacteria, which should be monitored sensitively and selectively for human health concerns. Traditional detection methods mainly rely on limulus amoebocyte lysate assay. However, it suffers drawbacks like the narrow detection range, and the results may be environment-dependent. In this work, we have developed a sensitive electrochemical biosensor for endotoxin assay. Peptide is first designed as specific recognition element toward endotoxin. Graphene oxide and DNA-modified gold nanoparticles are then used to enhance the electrochemical signal. The analytical performances are excellent with the limit of detection as low as 0.001 EU mL-1. This method has also been successfully applied in endotoxin assay in complex biological samples, which may have great potential use.

7.
ACS Appl Mater Interfaces ; 9(24): 20637-20647, 2017 Jun 21.
Article in English | MEDLINE | ID: mdl-28540731

ABSTRACT

Strain-mediated ferromagnetic/ferroelectric (FE) heterostructures have played an important role in multiferroic materials to investigate the electric-field control of magnetism in the past decade, due to their excellent performances, such as room-temperature operation and large magnetoelectric (ME) coupling effect. Because of the different FE-switching-originated strain behaviors and varied interfacial coupling effect, both loop-like (nonvolatile) and butterfly-like (volatile) converse ME effects have been reported. Here, we investigate the electric-field control of magnetism in a multiferroic heterostructure composed of a polycrystalline Fe thin film and a Pb(Mg1/3Nb2/3)0.7Ti0.3O3 single crystal, and the experimental results exhibit complex behaviors, suggesting the coexistence of volatile and nonvolatile converse ME effects. By separating the symmetrical and antisymmetrical parts of the electrical modulation of magnetization, we distinguished the loop-like hysteresis and butterfly-like magnetization changes tuned by electric fields, corresponding to the strain effects related to the FE 109° switching and 71/180° switching, respectively. Further magnetic-field-dependent as well as angular-dependent investigation of the converse ME effect confirmed the strain-mediated magnetism involving competition among the Zeeman energy, magnetocrystalline anisotropy energy, and strain-generated magnetoelastic energy. This study is helpful for understanding the electric-field control of magnetism in multiferroic heterostructures as well as its relevant applications.

8.
Adv Mater ; 29(4)2017 Jan.
Article in English | MEDLINE | ID: mdl-27862413

ABSTRACT

In magnetic logic, four basic Boolean logic operations can be programmed by a magnetic bit at room temperature with a high output ratio (>103 %). In the same clock cycle, benefiting from the built-in spin Hall effect, logic results can be directly written into magnetic bits using an all-electric method.

9.
ACS Appl Mater Interfaces ; 9(3): 2642-2649, 2017 Jan 25.
Article in English | MEDLINE | ID: mdl-28025891

ABSTRACT

Intrinsic spatial inhomogeneity or phase separation in cuprates, manganites, etc., related to electronic and/or magnetic properties, has attracted much attention due to its significance in fundamental physics and applications. Here we use scanning Kerr microscopy and scanning electron microscopy with polarization analysis with in situ electric fields to reveal the existence of intrinsic spatial inhomogeneity of the magnetic response to an electric field on a mesoscale with the coexistence of looplike (nonvolatile) and butterfly-like (volatile) behaviors in Co40Fe40B20/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 ferromagnetic/ferroelectric (FM/FE) multiferroic heterostructures. Both the experimental results and micromagnetic simulations suggest that these two behaviors come from the 109° and the 71°/180° FE domain switching, respectively, which have a spatial distribution. This FE domain-switching-controlled magnetism is significant for understanding the nature of FM/FE coupling on the mesoscale and provides a path for designing magnetoelectric devices through domain engineering.

10.
Stem Cells Transl Med ; 5(8): 1004-13, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27334487

ABSTRACT

UNLABELLED: : Stem cell therapy has emerged as a new strategy for treatment of ischemic heart disease. Although umbilical cord-derived mesenchymal stromal cells (UC-MSCs) have been used preferentially in the acute ischemia model, data for the chronic ischemia model are lacking. In this study, we investigated the effect of UC-MSCs originated from Wharton's jelly in the treatment of chronic myocardial ischemia in a porcine model induced by ameroid constrictor. Four weeks after ameroid constrictor placement, the surviving animals were divided randomly into two groups to undergo saline injection (n = 6) or UC-MSC transplantation (n = 6) through the left main coronary artery. Two additional intravenous administrations of UC-MSCs were performed in the following 2 weeks to enhance therapeutic effect. Cardiac function and perfusion were examined just before and at 4 weeks after intracoronary transplantation. The results showed that pigs with UC-MSC transplantation exhibited significantly greater left ventricular ejection fraction compared with control animals (61.3% ± 1.3% vs. 50.3% ± 2.0%, p < .05). The systolic thickening fraction in the infarcted left ventricular wall was also improved (41.2% ± 3.3% vs. 46.2% ± 2.3%, p < .01). Additionally, the administration of UC-MSCs promoted collateral development and myocardial perfusion. The indices of fibrosis and apoptosis were also significantly reduced. Immunofluorescence staining showed clusters of CM-DiI-labeled cells in the border zone, some of which expressed von Willebrand factor. These results suggest that UC-MSC treatment improves left ventricular function, perfusion, and remodeling in a porcine model with chronic myocardial ischemia. SIGNIFICANCE: Ischemic heart disease is the leading cause of death worldwide. Many patients with chronic myocardial ischemia are not suitable for surgery and have no effective drug treatment; they are called "no-option" patients. This study finds that umbilical cord-derived mesenchymal stromal cells transplanted by intracoronary delivery combined with two intravenous administrations was safe and could significantly improve left ventricular function, perfusion, and remodeling in a large-animal model of chronic myocardial ischemia, which provides a new choice for the no-option patients. In addition, this study used clinical-grade mesenchymal stem cells with delivery and assessment methods commonly used clinically to facilitate further clinical transformation.


Subject(s)
Coronary Circulation , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells , Myocardial Infarction/surgery , Umbilical Cord/cytology , Ventricular Function, Left , Ventricular Remodeling , Wharton Jelly/cytology , Angiogenic Proteins/metabolism , Animals , Apoptosis , Biomarkers/metabolism , Cell Differentiation , Cell Survival , Cells, Cultured , Collateral Circulation , Cytokines/metabolism , Disease Models, Animal , Female , Fibrosis , Humans , Mesenchymal Stem Cells/metabolism , Myocardial Contraction , Myocardial Infarction/metabolism , Myocardial Infarction/pathology , Myocardial Infarction/physiopathology , Myocardium/metabolism , Myocardium/pathology , Neovascularization, Physiologic , Phenotype , Recovery of Function , Stroke Volume , Swine , Time Factors , von Willebrand Factor/metabolism
11.
Adv Mater ; 28(14): 2760-4, 2016 Apr 13.
Article in English | MEDLINE | ID: mdl-26857904

ABSTRACT

The anomalous Hall effect of a magnetic material is coupled to the nonlinear transport effect of a semiconductor material in a simple structure to achieve a large geometric magnetoresistance (MR) based on a diode-assisted mechanism. An extremely large MR (>10(4) %) at low magnetic fields (1 mT) is observed at room temperature. This MR device shows potential for use as a logic gate for the four basic Boolean logic operations.

12.
Article in Chinese | MEDLINE | ID: mdl-26930938

ABSTRACT

OBJECTIVE: To evaluate the effect of soil-transmitted helminthes control through mass deworming and latrine improvement in rural areas. METHODS: The data including mass deworming (1998-2000) and latrine improvement (2001-2010) were collected, summarized and analyzed in Danyang City. The infection rate of the soil-transmitted helminthes was monitored annually by using Kato-Katz method from 2001 to 2010. In addition, 2 villages with the improved latrines strategy and one village without the strategy were selected for hygienic evaluation. RESULTS: Totally 1 130 000 person-times of mass deworming were carried out in Danyang City from 1998 to 2000, and the infection rate of soil transmitted helminthes of human was decreased from 40.82% to 1.10%. The infection rate (2.49%-4.81%) was bounced in the first five years (from 2001 to 2005) after mass deworming, while it gradually declined in the following five years (from 2006 to 2010) and maintained at a low level (0.07%-0.52%), and there was a significant difference between the average infection rates during the above two stages (χ2 = 353.83, P < 0.01). There was a negative correlation between the coverage rate of harmless latrine and the infection rate (r = -0.83, P < 0.01). CONCLUSION: The mass deworming and latrine improvement are effective measures for the control of soil-trans-mitted helminthes infection in rural areas.


Subject(s)
Helminthiasis/prevention & control , Helminths/physiology , Soil/parasitology , Toilet Facilities/standards , Adolescent , Adult , Age Factors , Aged , Animals , Anthelmintics/pharmacology , Child , China , Disease Eradication/methods , Disease Eradication/standards , Feces/parasitology , Female , Helminthiasis/diagnosis , Helminthiasis/parasitology , Helminths/drug effects , Humans , Male , Middle Aged , Rural Health/standards , Rural Health/statistics & numerical data , Sex Factors , Young Adult
13.
ScientificWorldJournal ; 2014: 150516, 2014.
Article in English | MEDLINE | ID: mdl-25506062

ABSTRACT

A method of damage identification of piles was established by using vibration characteristics. The approach focused on the application of the element strain energy and sensitive modals. A damage identification equation of piles was deduced using the structural vibration equation. The equation contained three major factors: change rate of element modal strain energy, damage factor of pile, and sensitivity factor of modal damage. The sensitive modals of damage identification were selected by using sensitivity factor of modal damage firstly. Subsequently, the indexes for early-warning of pile damage were established by applying the change rate of strain energy. Then the technology of computational analysis of wavelet transform was used to damage identification for pile. The identification of small damage of pile was completely achieved, including the location of damage and the extent of damage. In the process of identifying the extent of damage of pile, the equation of damage identification was used in many times. Finally, a stadium project was used as an example to demonstrate the effectiveness of the proposed method of damage identification for piles. The correctness and practicability of the proposed method were verified by comparing the results of damage identification with that of low strain test. The research provided a new way for damage identification of piles.


Subject(s)
Engineering , Stress, Mechanical , Vibration , Accelerometry , Finite Element Analysis , Models, Theoretical
14.
J Breast Cancer ; 17(4): 363-9, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25548585

ABSTRACT

PURPOSE: In the present study, we investigated the incidence of cardiotoxicity within 5 years of trastuzumab treatment and evaluated potential risk factors in clinical practice. METHODS: The study cohort included 415 patients diagnosed with early breast cancer (EBC). Cardiotoxicity incidence was evaluated in patients receiving trastuzumab and those who did not. Multivariate Cox proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals of potential risk factors for trastuzumab-related cardiotoxicity after appropriate adjustments. RESULTS: Incidence of cardiotoxicity in patients treated with trastuzumab was significantly higher than that in controls (23.7% vs. 10.8%, p<0.001). This result was adjusted for factors that might increase the risk of cardiotoxicity, such as history of coronary artery diseases or the use of anthracyclines for more than four cycles. CONCLUSION: Our findings indicated that treatment with trastuzumab was strongly associated with cardiotoxicity in EBC patients.

15.
Sci Rep ; 4: 6918, 2014 Nov 05.
Article in English | MEDLINE | ID: mdl-25370072

ABSTRACT

Quantum magnetic phase transition in square-octagon lattice was investigated by cellular dynamical mean field theory combining with continuous time quantum Monte Carlo algorithm. Based on the systematic calculation on the density of states, the double occupancy and the Fermi surface evolution of square-octagon lattice, we presented the phase diagrams of this splendid many particle system. The competition between the temperature and the on-site repulsive interaction in the isotropic square-octagon lattice has shown that both antiferromagnetic and paramagnetic order can be found not only in the metal phase, but also in the insulating phase. Antiferromagnetic metal phase disappeared in the phase diagram that consists of the anisotropic parameter λ and the on-site repulsive interaction U while the other phases still can be detected at T = 0.17. The results found in this work may contribute to understand well the properties of some consuming systems that have square-octagon structure, quasi square-octagon structure, such as ZnO.

16.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 25(2): 129-32, 136, 2013 Apr.
Article in Chinese | MEDLINE | ID: mdl-23894830

ABSTRACT

OBJECTIVE: To understand the dynamics and the diffusion trend of Oncomelania snails in Danyang City, Jiangsu Province, so as to explore effective control measures. METHODS: The data of historical records and routine surveillance of snails were collected and analyzed according to the river systems. RESULTS: The snails were imported from external river systems and spread from the rivers to inland. The diffusion trend was from the upstream to downstream and from the rivers to irrigation canals. CONCLUSION: The inland rivers connecting with the Yangtze River are the main routes where marshland snails can spread from outside to the inland. The irrigation system plays an important role in snail spreading to the irrigation areas. The regular surveillance in combination with the basic construction of farmland and irrigation system is needed to prevent the spread of the snails and the retransmission of schistosomiasis japonica in Danyang.


Subject(s)
Rivers , Snails/growth & development , Animals , Population Dynamics
17.
Mol Med Rep ; 7(2): 543-8, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23229202

ABSTRACT

A number of studies have evaluated the correlation between the cytochrome P450 1A1 (CYP1A1) T6235C polymorphism and coronary artery disease (CAD) risk, however, at present the results remain inconclusive. To provide a more robust investigation of this correlation, a meta-analysis was performed. In the present study, a systematic search of PubMed, Embase and CBM databases for studies published prior to June 6, 2012 was performed. The correlation between the CYP1A1 T6235C polymorphism and CAD risk was assessed by calculating pooled odds ratios (ORs) and 95% confidence intervals (95% CIs). Seven studies with a total of 2,903 cases and 2,304 controls were included in the meta-analysis. Overall, the CYP1A1 T6235C polymorphism was not correlated with CAD risk (C vs. T: OR=1.03; 95% CI, 0.87-1.22; P=0.728; CC vs. TT: OR=1.04; 95% CI, 0.84­1.19; P=0.699; CC+TC vs. TT: OR=1.04; 95% CI, 0.93-1.18; P=0.478; CC vs. TC+TT: OR=1.04; 95% CI, 0.85­1.28; P=0.704). A meta-analysis of five high-quality studies demonstrated that the CYP1A1 T6235C polymorphism is not correlated with risk of CAD in 4 genetic models. Ethnic subgroup analyses identified no significant correlation in Caucasian, Asian and African populations. The present meta-analysis study indicates that the CYP1A1 T6235C polymorphism is not correlated with CAD risk. Additional studies with a larger sample size and consistent design must be performed to confirm the present hypothesis.


Subject(s)
Coronary Artery Disease/genetics , Cytochrome P-450 CYP1A1/genetics , Polymorphism, Single Nucleotide , Coronary Artery Disease/ethnology , Coronary Artery Disease/pathology , Databases, Genetic , Genotype , Humans , Odds Ratio , Risk Factors
18.
Chin Med J (Engl) ; 125(19): 3472-8, 2012 Oct.
Article in English | MEDLINE | ID: mdl-23044308

ABSTRACT

BACKGROUND: Exposure of cells to sublethal concentrations of hydrogen peroxide (H2O2) can alleviate subsequent oxidative stress-induced apoptosis. We assessed the effects of H2O2 preconditioning on the therapeutic potential of human umbilical cord Wharton's Jelly mesenchymal stem cells (WJ-MSCs) in a murine model of myocardial infarction. METHODS: WJ-MSCs were incubated in the media for 2 hours with or without 200 µmol/L H2O2. Mice underwent left anterior descending coronary artery ligation, and received injection of phosphate buffered saline, 1×10(6) WJ-MSCs, or 1×10(6) H2O2 preconditioned WJ-MSCs 3 hours later via tail vein. Echocardiography was performed 0, 7, 14 and 28 days after surgery, and the mice were euthanized on day 28 for histological analysis. In vitro cytokine concentrations in the WJ-MSC cell supernatant were measured by enzyme-linked immunosorbent assay (ELISA). The effect of WJ-MSC cell supernatant on the migration and proliferation of endothelial cells were observed by transwell migration and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazoliumbromide (MTT) assays. RESULTS: Echocardiographic measurements revealed a significant improvement in the left ventricular contractility of the WJ-MSCs-H2O2 group compared to the WJ-MSCs group. Histological analysis revealed increased neovascularization and reduced myocardial fibrosis in the WJ-MSCs-H2O2 group compared to the WJ-MSCs group. Pretreatment of WJ-MSCs with H2O2 increased the secretion of interleukin-6 (IL-6) into the cell culture supernatant by approximately 25-fold. The culture supernatant from WJ-MSCs-H2O2 significantly increased the migration and proliferation of endothelial cells; these effects could be blocked using an anti-IL-6 antibody. CONCLUSIONS: This study demonstrates that H2O2 preconditioning significantly enhanced the therapeutic potential of WJ-MSCs, possibly by stimulating the production of IL-6 by WJ-MSCs, which may cause migration and proliferation of endothelial cells and increase neovascularization.


Subject(s)
Hydrogen Peroxide/pharmacology , Mesenchymal Stem Cells/drug effects , Myocardial Infarction/therapy , Wharton Jelly/cytology , Animals , Cell Movement/physiology , Echocardiography , Enzyme-Linked Immunosorbent Assay , Humans , Immunohistochemistry , Interleukin-6/metabolism , Male , Mesenchymal Stem Cell Transplantation , Mesenchymal Stem Cells/metabolism , Mice , Mice, Inbred C57BL , Myocardial Infarction/pathology , Reactive Oxygen Species/metabolism
19.
Article in Chinese | MEDLINE | ID: mdl-22164501

ABSTRACT

OBJECTIVE: To evaluate the effectiveness of blocking diffusion of Oncomelania snails with the blocking network via collecting water from middle layer. METHODS: According to the principle of the installation preventing snails via collecting water from middle layer without snails, the blocking network was manufactured. The field test of the blocking diffusion of snails with the blocking network was carried out in the electric pumping station and the irrigation located in the area with snails. The snails stained were put into the water inlet of the pump when the pump was actuating, and the snails pumped were observed during the test period. The cost of the test was also calculated. RESULTS: The rate of blocking diffusion of snails with the blocking network was 100%, and the direct costs were only 11 030 CNY. CONCLUSIONS: The blocking network via collecting water from middle layer has good effect for prevention of snail dispersal. It is simple for manutacturing and installation, and suitable for emergency blocking diffusion of snails in the east route of South-to-North Water Diversion Project and the electric pumping station with snails.


Subject(s)
Pest Control/methods , Schistosomiasis/prevention & control , Snails/growth & development , Technology/methods , Animals , Humans , Pest Control/economics , Pest Control/instrumentation , Rivers/parasitology , Schistosomiasis/economics , Schistosomiasis/parasitology , Snails/parasitology , Technology/economics
20.
Nature ; 477(7364): 304-7, 2011 Sep 14.
Article in English | MEDLINE | ID: mdl-21921912

ABSTRACT

Inhomogeneity-induced magnetoresistance (IMR) reported in some non-magnetic semiconductors, particularly silicon, has generated considerable interest owing to the large magnitude of the effect and its linear field dependence (albeit at high magnetic fields). Various theories implicate spatial variation of the carrier mobility as being responsible for IMR. Here we show that IMR in lightly doped silicon can be significantly enhanced through hole injection, and then tuned by an applied current to arise at low magnetic fields. In our devices, the 'inhomogeneity' is provided by the p-n boundary formed between regions where conduction is dominated by the minority and majority charge carriers (holes and electrons) respectively; application of a magnetic field distorts the current in the boundary region, resulting in large magnetoresistance. Because this is an intrinsically spatial effect, the geometry of the device can be used to enhance IMR further: we designed an IMR device whose room-temperature field sensitivity at low fields was greatly improved, with magnetoresistance reaching 10% at 0.07 T and 100% at 0.2 T, approaching the performance of commercial giant-magnetoresistance devices. The combination of high sensitivity to low magnetic fields and large high-field response should make this device concept attractive to the magnetic-field sensing industry. Moreover, because our device is based on a conventional silicon platform, it should be possible to integrate it with existing silicon devices and so aid the development of silicon-based magnetoelectronics.

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