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We report the control of Rashba spin-orbit interaction by tuning asymmetric hybridization between Ti orbitals at the LaAlO_{3}/SrTiO_{3} interface. This asymmetric orbital hybridization is modulated by introducing a LaFeO_{3} layer between LaAlO_{3} and SrTiO_{3}, which alters the Ti-O lattice polarization and traps interfacial charge carriers, resulting in a large Rashba spin-orbit effect at the interface in the absence of an external bias. This observation is verified through high-resolution electron microscopy, magnetotransport and first-principles calculations. Our results open hitherto unexplored avenues of controlling Rashba interaction to design next-generation spin orbitronics.
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A topological meron features a non-coplanar structure, whose order parameters in the core region are perpendicular to those near the perimeter. A meron is half of a skyrmion, and both have potential applications for information carrying and storage. Although merons and skyrmions in ferromagnetic materials can be readily obtained via inter-spin interactions, their behaviour and even existence in ferroelectric materials are still elusive. Here we observe using electron microscopy not only the atomic morphology of merons with a topological charge of 1/2, but also a periodic meron lattice in ultrathin PbTiO3 films under tensile epitaxial strain on a SmScO3 substrate. Phase-field simulations rationalize the formation of merons for which an epitaxial strain, as a single alterable parameter, plays a critical role in the coupling of lattice and charge. This study suggests that by engineering strain at the nanoscale it should be possible to fabricate topological polar textures, which in turn could facilitate the development of nanoscale ferroelectric devices.
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Objective: To examine the long-term efficacy of radiofrequency closure in the treatment of great saphenous vein varicose. Methods: The clinic data of 185 patients with varicose veins of lower limbs treated with radiofrequency closure admitted at Department of Vascular Surgery, Beijing Shijitan Hospital, Capital Medical University from July 2016 to January 2017 was analyzed retrospectively. A total of 203 limbs were treated by radiofrequency closure. The long-term efficacy of radiofrequency closure was evaluated by analyzing the closure rate, clinical-etiology- anatomy-pathophysiology (CEAP) grading, venous clinical severity score (VCSS), chronic venous insufficiency questionnaire (CIVIQ) score, and complications, using repeated measures analysis of variance. Results: All procedures were successful. The closure rate was 98.0% (199/203) at one year and two years postoperative, which was still maintained at 97.5% (198/203) at 3 years of follow-up. Postoperative CEAP grading was significantly downgraded compared with that before the operation. Totally 88.4% (76/86) of C5 to C6 grade patients downgraded to C2 to C4 grade at 6 months, and 95.3% (82/86) downgraded to C0 to C2 garde at 3 years postoperative. VCSS and CIVIQ score in both groups significantly improved at all follow-up time points compared to preoperative scores (VCSS: F=1 064.7, P=0.003; CIVIQ score: F=2 984.3, P=0.001). The most common complication was subcutaneous blood stasis (10.8%), most of which disappeared within 1 month after the surgery. Other complications included pigmentation and thrombophlebitis (5.9% and 3.9%, respectively). Conclusion: The long-term efficacy of radiofrequency closure of the great saphenous vein is satisfactory.
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Várices , Insuficiencia Venosa , Humanos , Estudios Retrospectivos , Vena Safena/cirugía , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Várices/cirugía , Insuficiencia Venosa/cirugíaRESUMEN
Internal ribosomal entry site (IRES) functions as a cis-acting RNA element, which drives an alternative and cap-independent translation initiation pathway. Currently, there are few studies on effects of nucleotide usages at key nucleotide positions +4 and -3 flanking start codon mediated by IRES of hepatitis C virus (HCV). Herein, we focus on the effect of nucleotide usages at -3 and +4 positions mediated by HCV IRES. The nucleotide contexts flanking AUG start codon employed by HCV IRES is firstly analyzed. We found that each position in the six nucleotide positions (-4 to +6) flanking start codon of HCV has a strong tendency to select the specific nucleotide. A set of bicistronic expression vectors containing CAT gene, HCV IRES and EGFP gene were constructed, including 16 different nucleotide combinations at position -3 and +4. Each set, in which nucleotide at the -3 and +4 position has been changed into different nucleotides, included 16 types of bicistronic expression vectors. It was found that the purine nucleotide at the position -3 or +4 obviously impacts on HCV IRES-related expression, and IRES-driven translation is potentially influenced by the Kozak rule. Our results suggest that optimization of nucleotides at positions -3 and +4 is a convenient and efficient way to enhance the level of IRES-mediated translation. Keywords: Cap-independent translation; internal ribosomal entry site; hepatitis C virus; bicistronic expression vector; translation efficiency.
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Hepacivirus , Sitios Internos de Entrada al Ribosoma , Nucleótidos , Codón Iniciador , Hepacivirus/genética , Nucleótidos/genética , Biosíntesis de Proteínas , ARN Viral , Secuencias Reguladoras de Ácidos NucleicosRESUMEN
The magnetoelectric (ME) effect originating from the effective coupling between electric field and magnetism is an exciting frontier in nanoscale science such as magnetic tunneling junction (MTJ), ferroelectric/piezoelectric heterojunctions etc. The realization of switchable ME effect under external electric field in d0 semiconducting materials of single composition is needed especially for all-silicon spintronics applications because of its natural compatibility with current industry. We employ density functional theory (DFT) to reveal that the pristine Si(111)-3×3 R30° (Si3 hereafter) reconstructed surfaces of thin films with a thickness smaller than eleven bilayers support a sizeable linear ME effect with switchable direction of magnetic moment under external electric field. This is achieved through the interlayer exchange coupling effect in the antiferromagnetic regime, where the spin-up and spin-down magnetized density is located on opposite surfaces of Si3 thin films. The obtained coefficient for the linear ME effect can be four times larger than that of ferromagnetic Fe films, which fail to have the reversal switching capabilities. The larger ME effect originates from the spin-dependent screening of the spin-polarized Dirac fermion. The prediction will promote the realization of well-controlled and switchable data storage in all-silicon electronics.
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Objective: To increase the consciousness of incident deep venous thrombosis (DVT) in hospitalized patients. Methods: This is a retrospective study of hospitalized patients with DVT in Beijing Shijitan Hospital from 2007 to 2016. Clinical features of DVT patients who were admitted with no DVT were summarized. The demographic and epidemiological characteristics, involved site of veins, department of patients and risk factors were discussed. Results: A total of 5 063 patients were complicated with DVT from 305 922 inpatients who were without DVT at the admission during past 10 years. Among them, 54.36% (2 752/5 063) were men. The age of the patients was (74.1±15.9) years old (range 1-103 years) with 37.78% of them in 80 to 89 age group. The incidence of DVT in the hospital was 1.65%. It increased yearly during the past decade (from 0.50% to 2.74%), and increased with age in patients from 1 to 99 years old (7.32% in 90-99 age group). Totally, 5 204 veins were involved in the patients. Most thrombosis involved inferior vena cava system (96.54%,5 024/5 204), especially deep veins of lower extremity (83.78%,4 360/5 204), some involved portal veins (8.61%,448/5 204) and a little was found in superior venae cava (3.46%, 180/5 204). More DVT patients were in department of internal medicine than those in department of surgery (2.95% vs 0.97%, P<0.01). ICU had the highest rate of DVT among the hospital departments (9.75%). No DVT occurred in department of newborn. Risk factors of DVT were inflammatory diseases (71.54%), age over 75 years old (67.25%), and heart diseases (58.98%). Conclusion: Sensitivity of detection on DVT should be emphasized in hospitalized patients with DVT risk, especially at the department with high incident of DVT.
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Hospitalización/estadística & datos numéricos , Pacientes Internos/estadística & datos numéricos , Vena Cava Inferior/fisiopatología , Trombosis de la Vena/epidemiología , Adolescente , Adulto , Distribución por Edad , Factores de Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , China/epidemiología , Femenino , Humanos , Incidencia , Lactante , Extremidad Inferior/irrigación sanguínea , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Adulto JovenRESUMEN
As for the alternative AUGs in foot-and-mouth disease virus (FMDV), nucleotide bias of the context flanking the AUG(2nd) could be used as a strong signal to initiate translation. To determine the role of the specific nucleotide context, dicistronic reporter constructs were engineered to contain different versions of nucleotide context linking between internal ribosome entry site (IRES) and downstream gene. The results indicate that under FMDV IRES-dependent mechanism, the nucleotide contexts flanking start codon can influence the translation initiation efficiencies. The most optimal sequences for both start codons have proved to be UUU AUG(1st) AAC and AAG AUG(2nd) GAA.
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Codón Iniciador/genética , Virus de la Fiebre Aftosa/genética , Fiebre Aftosa/virología , Biosíntesis de Proteínas , Animales , Secuencia de Bases , Virus de la Fiebre Aftosa/química , Virus de la Fiebre Aftosa/aislamiento & purificación , Virus de la Fiebre Aftosa/metabolismo , Humanos , Datos de Secuencia Molecular , ARN Viral/química , ARN Viral/genética , ARN Viral/metabolismoRESUMEN
The titin immunoglobulin domain (TTID) protein localizes to the Z line in muscle and binds to alpha-actinin and gamma-filamin. It plays an indispensable role in stabilizing and anchoring of thin filaments. In this study, the 5'-regulatory region of the porcine TTID gene was analyzed with bioinformatic methods. Another objective of this study was to further investigate the polymorphism in the intron 6 of the porcine TTID gene. We determined allele frequency among six Chinese porcine purebreds. The polymorphisms were genotyped in a population of 280 F2 pigs representing two Large White x Meishan reference families. Different TTID genotypes were significantly associated with carcass traits, including skin percentage (P < 0.05), loin eye area (P < 0.05), and average skin thickness (P < 0.01). Our study will continue to lay the groundwork for further investigations into the detailed function of the porcine TTID gene.
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Composición Corporal , Conectina/genética , Estudios de Asociación Genética/métodos , Región de Flanqueo 5' , Crianza de Animales Domésticos , Animales , Secuencia de Bases , Frecuencia de los Genes , Genotipo , Análisis de los Mínimos Cuadrados , Datos de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , PorcinosRESUMEN
MicroRNAs (miRNAs) are small non-coding RNA molecules that play key roles in the regulation of development processes of many tissues and organs at the post-transcriptional level. However, little is known about how they affect chicken gonadal development. We examined the expression of four miRNAs (miR-218, -200b, -196, and -206) in chicken embryonic gonads at embryonic days 3.5-6.5. Their target genes were predicted by miRDB, TargetScan and PicTar algorithms. The expression levels of these four miRNAs differed with sex to varying degrees; miR-200b was expressed at a significantly higher level in female gonads during the entire interval. The whole mount in situ hybridization result showed considerably higher expression of miR-200b in females than in males in E5.5 embryos. The miRNA target scanning results indicated several genes with functions in gonad development and gonad function. We conclude that miR-200b is involved in the regulation of gonad development and sexual differentiation of chicken embryos.
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Regulación del Desarrollo de la Expresión Génica , MicroARNs/biosíntesis , Diferenciación Sexual/genética , Animales , Embrión de Pollo , Pollos/genética , Femenino , Perfilación de la Expresión Génica , Gónadas/crecimiento & desarrollo , Gónadas/metabolismo , Hibridación in Situ , Masculino , MicroARNs/genética , Ovario/crecimiento & desarrollo , Ovario/metabolismoRESUMEN
Nucleotide and codon usage are typically examined to investigate viral evolution. In this study, we analyzed the genetic information of 46 strains of classical swine fever virus (CSFV) RNA, nucleotide usage in the internal ribosome entry site (IRES), the nucleotide context surrounding the initiation codon, and synonymous codon usage in the translation initiation region. Phylogenetic analysis of the IRES element indicated that the genetic diversity of this element is generally similar to the phylogenetic clusters of CSFV genotypes. Nucleotides surrounding the initiation codon of CSFV RNA were generally more stable (ACAUGGCACAUGGAGUUG) compared to the internal AUG in the CSFV coding sequence. The second codon position after the initiation codon was generally selected to be GAG, which has lower tRNA abundance in pigs than its synonymous member (GAA). Regarding the synonymous codon usage bias in the CSFV translation initiation region, some codons showing low tRNA abundance in pigs are more frequently located in the translation initiation region than in the open reading frame of CSFV. Although CSFV, similarly to other RNA viruses, has a high mutation rate in nature, the regulatory features of nucleotide and synonymous codon usage of the IRES element, the nucleotide context surrounding the initiation codon and the translation initiation region in CSFV RNA have been 'branded' in the system of translation initiation to accommodate gene expression mediated by the cap-independent translation mechanism.
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Virus de la Fiebre Porcina Clásica/clasificación , Virus de la Fiebre Porcina Clásica/genética , ARN Viral/genética , Secuencias Reguladoras de Ácido Ribonucleico , Animales , Virus de la Fiebre Porcina Clásica/fisiología , Codón Iniciador , Evolución Molecular , Variación Genética , Filogenia , Biosíntesis de Proteínas , ARN de Transferencia/genética , Análisis de Secuencia de ARNRESUMEN
Adaptation in the overall codon usage pattern of West Nile virus (WNV) to that of two hosts was estimated based on the synonymous codon usage value (RSCU). Synonymous codon usage biases for the beginning coding sequence of this virus were also analyzed by calculating the usage fluctuation for each synonymous codon along the target region (the first 270 codon sites of the whole coding sequence of WNV). Adaptation of WNV to Anopheles gambiae regarding the overall codon usage revealed a mixture of synonymous codon usage patterns between this virus and its vector. Regarding the adaptation of WNV to its dead-end host and codon usage, although a mixture of overall codon usage patterns exists, the number of codons with reversed tendency codon usage is lower than that between the virus and its vector. In addition, some codons with low RSCU values for this virus are highly selected in the beginning translation region of WNV, while codons with low RSCU values in this region tend to pair with tRNAs present in low abundance in the host, suggesting that highly selected codons in a specific region in the beginning region of WNV are, to some degree, influenced by the corresponding low tRNA abundance of hosts to regulate the translation speed of the WNV polyprotein.
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Codón , Sistemas de Lectura Abierta , ARN Viral , Virus del Nilo Occidental/genética , Interacciones Huésped-Patógeno , ARN de TransferenciaRESUMEN
The synonymous codon usage patterns in the initial and terminal translation regions (ITR, TTR) of the whole coding sequence of encephalomyocarditis virus (EMCV) were analyzed in relation to those in its natural hosts using the sequences accessible in databases. In general, some low-usage host codons were found over-represented in the ITR and TTR of the virus, while some high-usage host codons were found under-represented in the two viral regions. These relationships are thought to participate in the regulation of the speed of translation of viral proteins and in the suppression of ribosomal traffic jams, both aiming at the increase of virus yields.
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Codón , Virus de la Encefalomiocarditis/genética , Regulación Viral de la Expresión Génica/fisiología , Secuencia de Aminoácidos , Secuencia de Bases , Datos de Secuencia Molecular , ARN Viral/genéticaRESUMEN
To analyze the synonymous codon usage patterns of sequence regions flanking cleavage sites in the hepatitis A virus (HAV) polyprotein, the codon usage bias at codon positions and the synonymous codon usage in the target contexts of 30 virus strains were estimated by two simple methods that were based on the values for relative synonymous codon usage. In addition, the pattern of synonymous codon usage was compared between the genomic sequences in HAV and those of its human host. Our results indicated that HAV adopts a combination of coincidence and antagonism with the synonymous codon usage in humans. This characteristic may help HAV to efficiently use the translational machinery in its human host. We also observed that codon usage exhibited a strong bias in some specific positions in these contexts, and that the underrepresented synonymous codons, CUA for Leu, ACG for Thr, GUA for Val, and UCG for Ser, are preferentially used in these positions. These underrepresented synonymous codons likely play roles in regulating the rate of protein translation and influencing the secondary structure of the sequence regions flanking the cleavage sites.
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Codón/genética , Virus de la Hepatitis A/genética , Poliproteínas/genética , Proteolisis , Proteínas Virales/genética , ADN Viral/química , ADN Viral/metabolismo , Genoma Humano , Genoma Viral , Virus de la Hepatitis A/metabolismo , Humanos , Poliproteínas/metabolismo , Análisis de Secuencia de ADN , Proteínas Virales/metabolismoRESUMEN
1. Two splice variants of duck LRP8 were identified, one containing 8 ligand-binding repeats (LRP8-1) and the other containing only 7 repeats (LRP8-2). The two transcripts share ~71-91% nucleic acid identity and ~65-94% amino acid identity with their counterparts in other species. A phylogenetic tree based on amino acid sequences shows that duck LRP8 proteins are closely related to those of chicken, turkey and zebra finch. 2. The semi-quantitative reverse transcription polymerase chain reaction (RT-PCR )analysis indicates that the two transcripts are expressed in all the examined tissues, and the LRP8-1 transcript is more highly expressed in hypothalamus, ovary and pituitary gland than in other detected tissues. 3. Six single nucleotide polymorphisms (SNPs) were identified in the coding region. Association analysis demonstrated that the c.528C > T genotypes were associated with egg production (EP) (EP210d, EP300d and EP360d), age at laying the first egg (AFE) and body weight at sexual maturity (BWSM). The c.1371A > G genotypes were associated with egg production (EP210d, EP300d and EP360d). 4. The haplotypes of c.528C > T and c.1371A > G were associated with EP (EP210d, EP300d and EP360d), yolk weight (YW), albumen weight (AW), egg weight (EW), BWSM and the first egg weight (FEW). 5. Duck LRP8 gene was associated with some reproductive traits and is an important candidate gene for the genetic selection of improved reproductive traits.
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Patos/fisiología , Regulación de la Expresión Génica/fisiología , Proteínas Relacionadas con Receptor de LDL/fisiología , Filogenia , Polimorfismo Conformacional Retorcido-Simple/fisiología , Reproducción/fisiología , Animales , Secuencia de Bases , Clonación Molecular , Cruzamientos Genéticos , Patos/genética , Femenino , Regulación de la Expresión Génica/genética , Estudio de Asociación del Genoma Completo , Haplotipos , Proteínas Relacionadas con Receptor de LDL/genética , Datos de Secuencia Molecular , Polimorfismo de Longitud del Fragmento de Restricción , Polimorfismo Conformacional Retorcido-Simple/genética , ARN/química , ARN/genética , Reproducción/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/veterinaria , Alineación de Secuencia , Análisis de Secuencia de ADNRESUMEN
Objective: To explore the pathological characteristics of three mice models of temporomandibular joint degenerative joint disease (TMJDJD), including osteoarthritis and osteoarthrosis, and to provide references for animal experimental study regarding the pathological mechanism of osteoarthritis and osteoarthrosis. Methods: A total of 54 8-week-old male C57BL/6 mice were selected to construct three TMJDJD animal models, including bilateral temporomandibular joint (TMJ) Freund's complete adjuvant (FCA) injection model, bilateral TMJ monosodium iodoacetate (MIA) injection model, and right TMJ discectomy model. FCA injection model (15 mice) was divided into saline injection group, FCA injection group-1 week, FCA injection group-2 week, FCA injection group-4 week and FCA injection group-6 week, 3 mice were used at each time point, with a total of 6 TMJs on both sides. MIA injection model (15 mice) was separated into saline injection group, MIA injection group-1 week, MIA injection group-2 week, MIA injection group-4 week and MIA injection group-6 week, 3 mice were used at each time point, with a total of 6 TMJs on both sides. TMJ discectomy model (24 mice) was split into control group, discectomy group-2 week group, discectomy group-4 week and discectomy group-6 week, six mice were used at each time point, with a total of six right TMJs. General pictures of the bilateral joints area of mice were collected 1 day after drug injection, and stereoscopic images of condylar tissues were collected 4 weeks after microsurgery for discectomy. Mouse TMJ tissue sections from each time point were stained with HE and toluidine blue, respectively, synovial tissues were scored for synovial inflammation, and the percentage of proteoglycan in condylar cartilage was quantitatively analyzed. Results: One day after intra-articular FCA or MIA injection, the width of bilateral TMJ were significantly increased in FCA injection groups [(24.60±0.46) mm] compared with the saline injection group [(21.63±0.52) mm] (t=4.25, P<0.013), the width of bilateral TMJ in MIA injection groups [(24.50±0.62) mm] were also significantly higher than that in saline injection group [(21.40±0.52) mm] (t=3.82, P=0.019). The synovitis scores in FCA injection groups 1, 2, 4, 6 weeks after FCA injection were significantly higher than that of the saline injection group (F=18.09, P<0.001), with the proteoglycan of condylar cartilage increased firstly and then decreased compared with the saline injection group (F=21.59, P<0.001). Condylar cartilage proteoglycan loss in different degrees were observed 1, 2, 4 and 6 weeks after MIA injection (F=13.59, P<0.001), and synovitis scores were increased at different degrees compared with saline injection group (F=14.79, P<0.001). The morphology of condylar cartilage in discectomy groups mice were severely damaged, synovial tissues showed dense connective tissue lesions at 2, 4 and 6 weeks postoperatively, condylar cartilage tissues showed a time-dependent loss of proteoglycan compared with the control group (F=40.62, P<0.001). Conclusions: Intra-articular FCA injection establishes a mouse model of TMJ osteoarthritis with severe synovial inflammation. Intra-articular MIA injection constructs a mouse model of typical TMJ osteoarthritis. Discectomy establishes a mouse TMJ osteoarthrosis model with severe condylar cartilage destruction.
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Cartílago Articular , Osteoartritis , Sinovitis , Ratones , Masculino , Animales , Osteoartritis/patología , Ácido Yodoacético , Cloruro de Tolonio , Ratones Endogámicos C57BL , Articulación Temporomandibular/patología , Modelos Animales de Enfermedad , Proteoglicanos , Sinovitis/patología , Inflamación/patologíaRESUMEN
High-index perovskite ferroelectric thin films possess excellent dielectric permittivity, piezoelectric coefficient, and exotic ferroelectric switching properties. They also exhibit complications in the ferroelastic domains, misfit dislocations, and strain-relaxation behaviors. Exploring the relationship of the ferroelastic domains and misfit dislocations may be of benefit for promoting the high-quality growth of these thin films. Here, the strain field of the ferroelastic domains and misfit dislocations in [101]-oriented PbTiO3/(La, Sr)(Al, Ta)O3 epitaxial thin films were investigated by advanced aberration-corrected (scanning) transmission electron microscopy (TEM) combined with geometry phase analysis (GPA). Two types of misfit dislocations with projected Burgers vectors of a[001] or a[100] on the (010) plane were elucidated, whose strain fields included in-plane strain and lattice rotation coupled with the c domains above them. Besides, it was demonstrated that the coupling was kept inside the PbTiO3 films when the film thickness was increased. Furthermore, the polarization rotation was observed in both narrow c domains and around the misfit dislocation cores, which may be attributed to the flexoelectric effect. These results are expected to provide useful information for understanding the nucleation and propagation mechanism of ferroelastic domains and for further modifying the growth of high-index ferroelectric thin films.
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Band gap narrowing is important for applications of ZnO, especially for photoelectrochemical water splitting. In this work, we carried out first-principles electronic structure calculations with a hybrid density functional on defected ZnO. It is found that nitrogen substitutional doping alone cannot explain the largely enhanced conversion efficiency observed in nitrogen doped ZnO. Instead, complex defects formed by substitutional nitrogen and intrinsic defects play an important role in the band gap narrowing, in agreement with recent experimental results. We propose ZnO fabricated in a Zn-rich environment with heavy nitrogen doping as a photocatalyst for hydrogen generation from water splitting. A method for controlling the band gap of ZnO is also proposed.
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Objective: To investigate the effects and mechanism of sodium hydrosulfide on rat epidermal cells intervened with serum from burned rat (hereinafter referred to as burn serum). Methods: The experimental research method was used. Ten male Sprague-Dawley (SD) rats aged eight months were taken to prepare normal rat serum (hereinafter referred to as normal serum), 30 male SD rats aged eight months were taken to prepare burn serum after full-thickness burn, and epidermal cells (the third passage)isolated from 10 SD rats born one day were used for the experiments. The cells were divided into normal serum group treated with normal serum and burn serum group treated with burn serum. Cell counting kit 8 method was used to detect cell survival rate after 1, 2, 4, 6, and 8 h of culture, respectively, to screen the subsequent intervention time of burn serum. The cells were divided into burn serum control group treated only with burn serum and 50, 100, 150, 200, 250 µmol/L sodium hydrosulfide groups treated with burn serum+ sodium hydrosulfide at corresponding final molarity. After 30 min of culture following the burn serum intervention, the cell survival rate was detected as above to screen the subsequent intervention concentration of sodium hydrosulfide. The cells were divided into burn serum control group treated with burn serum only and sodium hydrosulfide only group, glibenclamide only group, and sodium hydrosulfide+ glibenclamide group treated with burn serum+ corresponding reagents. After 5, 10, 15 min of culture following the burn serum intervention, the cell survival rate was detected as above to screen the subsequent intervention time of glibenclamide. The cells were divided into burn serum control group treated with burn serum and sodium hydrosulfide only group, glibenclamide only group, and sodium hydrosulfide+ glibenclamide group treated with burn serum+ corresponding reagents. After completing corresponding culture time of each reagent, the mitochondria were extracted to detect cytochrome c oxidase (CCO) activity using a spectrophotometer, and the protein expression level of adenosine triphosphate (ATP)-sensitive potassium channel was detected by Western blotting. Except for the number of samples for ATP-sensitive potassium channel protein detection, which was 3, the number of samples for the other indicators was 10. Data were statistically analyzed with analysis of variance for factorial design, one-way analysis of variance, least significant difference (LSD)-t test, LSD test, and Bonferroni correction. Results: Compared with that of normal serum group, the cell survival rate was significantly decreased in burn serum group after only 4 and 6 h of culture (t=4.02, 6.42, P<0.05). An overall comparison showed statistically significant differences in cell survival rate among the time points within normal serum group and burn serum group (F=19.74, 4.48, P<0.05 or P<0.01). Four hours of culture was selected as the subsequent intervention time of burn serum. After 30 min of culture following the burn serum intervention, compared with that of burn serum control group, only 150, 200, 250 µmol/L sodium hydrosulfide groups had a significantly higher cell survival rate (P<0.01), thus 150 µmol/L was selected as the subsequent intervention concentration of sodium hydrosulfide. Compared with that of burn serum control group, the cell survival rate decreased significantly in glibenclamide only group after 5 and 15 min of culture following burn serum intervention (P<0.05) and increased significantly in glibenclamide only group after 10 min of culture following the burn serum intervention and sodium hydrosulfide only group at each time point (P<0.05 or P<0.01). The cell survival rate in sodium hydrosulfide+ glibenclamide group was significantly lower than that of sodium hydrosulfide only group at each time point (P<0.05). The difference in cell survival rate was statistically significant among the time points within glibenclamide only group (F=11.81, P<0.01). Five minutes of culture was selected as the subsequent intervention time of glibenclamide. After 35 min of culture following the burn serum intervention, compared with (1.62±0.08) nmol·min(-1)·mg(-1) and 0.682±0.063 in burn serum control group, the CCO activity of cells and the protein expression level of ATP-sensitive potassium channel were significantly increased in sodium hydrosulfide only group ((1.99±0.09) nmol·min(-1)·mg(-1) and 0.932±0.014, P<0.01) and significantly decreased in glibenclamide only group ((1.44±0.09) nmol·min(-1)·mg(-1) and 0.600±0.012, P<0.01); the CCO activity of cells and the protein expression level of ATP-sensitive potassium channel in sodium hydrosulfide+ glibenclamide group ((1.79±0.06) nmol·min(-1)·mg(-1) and 0.744±0.071) was significantly lower than those of sodium hydrosulfide only group (P<0.05 or P<0.01). Conclusions: Sodium hydrosulfide can improve the survival rate of rat epidermal cells after burn serum intervention, by a mechanism which is related to the alleviation of epidermal cell mitochondrial damage and mediated by ATP-sensitive potassium channel.
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Quemaduras , Animales , Quemaduras/tratamiento farmacológico , Células Epidérmicas , Masculino , Ratas , Ratas Sprague-Dawley , Suero , SulfurosRESUMEN
We report direct evidence of room-temperature ferromagnetic ordering in O-deficient ZnO:Cu films by using soft x-ray magnetic circular dichroism and x-ray absorption. Our measurements have revealed unambiguously two distinct features of Cu atoms associated with (i) magnetically ordered Cu ions present only in the oxygen-deficient samples and (ii) magnetically disordered regular Cu2+ ions present in all the samples. We find that a sufficient amount of both oxygen vacancies (V(O)) and Cu impurities is essential to the observed ferromagnetism, and a non-negligible portion of Cu impurities is uninvolved in the magnetic order. Based on first-principles calculations, we propose a microscopic "indirect double-exchange" model, in which alignments of localized large moments of Cu in the vicinity of the V(O) are mediated by the large-sized vacancy orbitals.
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We demonstrate, both theoretically and experimentally, that cation vacancy can be the origin of ferromagnetism in intrinsic dilute magnetic semiconductors. The vacancies can be controlled to tune the ferromagnetism. Using Li-doped ZnO as an example, we found that while Li itself is nonmagnetic, it generates holes in ZnO, and its presence reduces the formation energy of Zn vacancy, and thereby stabilizes the zinc vacancy. Room temperature ferromagnetism with p type conduction was observed in pulsed laser deposited ZnO:Li films with certain doping concentration and oxygen partial pressure.