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We report the use of halogen bonding (XB) for the generation of aryl radicals from aryl halides under blue light irradiation and applied it in radical generation/1,5-hydrogen-atom transfer/radical cyclization cascade reactions for the synthesis of oxindoles and isoindolinones. On the basis of experimental studies, we propose that DBU can serve as a suitable XB acceptor with aryl halides for the formation of a photoactive electron donor and acceptor complex.
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AIM AND BACKGROUND: Postoperative nausea and vomiting (PONV) remains a significant clinical problem for surgical patients. Amisulpride is a well-studied D2/D3 antagonist that has the potential to be used for preventing and treating PONV. Our aim was to assess the efficacy and safety of amisulpride for prevention and treatment of PONV through a systematic review and meta-analysis. METHOD: A systematic literature search was performed using MEDLINE, EMBASE, PUBMED, clinicaltrials.gov, and the Cochrane Central Register of Controlled Trials from their inception to Feb 15th, 2019. The efficacy outcome was the incidence of complete response, defined as no emesis and no rescue antiemetic use in a 24-h period after study drug administration. The safety outcomes were the adverse effects associated with amisulpride. RESULTS: Five studies comprising 3243 patients met inclusion critieria. Compared with placebo, amisulpride showed a significantly improved incidence of complete response [relative risk (RR): 1.30; 95% confidence interval (CI): 1.20-1.41; P < 0.00001, I2 = 0%] with firm evidence from the trial sequential analysis. Particularly, the amisulpride at 5 mg dose indicated a significant benefit than placebo [relative risk (RR): 1.28; 95% confidence interval (CI): 1.18-1.39; P < 0.00001, I2 = 4%]. The adverse event profile of amisulpride was generally similar to the placebo. CONCLUSION: Based on our findings, low-dose, intravenous amisulpride is safe and efficacious for the prevention and treatment of PONV compared to placebo. Further studies are needed to explore the optimal dose and timing. CLINICAL TRIAL REGISTRATION: PROSPERO: CRD42019121483.
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Amisulprida/uso terapéutico , Antagonistas de Dopamina/uso terapéutico , Náusea y Vómito Posoperatorios/tratamiento farmacológico , Humanos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Catalytic activation of Caryl-O bonds is considered as a powerful strategy for the production of aromatics from lignin. However, due to the high reduction potentials of diaryl ether 4-O-5 linkage models, their single electron reduction remains a daunting challenge. This study presents the blue light-induced bifunctional N-heterocyclic carbene (NHC)-catalyzed one-electron reduction of diaryl ether 4-O-5 linkage models for the synthesis of trivalent phosphines. The H-bond between the newly devised bifunctional NHC and diaryl ethers is responsible for the success of the single electron transfer. Furthermore, this approach demonstrates selective one-electron reduction of unsymmetric diaryl ethers, oligomeric phenylene oxide, and lignin model.
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Stacking engineering in van der Waals (vdW) materials is a powerful method to control topological electronic phases for quantum device applications. Atomic intercalation into the vdW material can modulate the stacking structure at the atomic scale without a highly technical protocol. Here we report that lithium intercalation in a topologically structured graphene/buffer system on SiC(0001) drives dynamic topological domain wall (TDW) motions associated with stacking order change by using an in situ aberration-corrected low-energy electron microscope in combination with theoretical modelling. We observe sequential and selective lithium intercalation that starts at topological crossing points (AA stacking) and then selectively extends to AB stacking domains. Lithium intercalation locally changes the domain stacking order to AA and in turn alters the neighbouring TDW stacking orders, and continuous intercalation drives the evolution of the whole topological structure network. Our work reveals moving TDWs protected by the topology of stacking and lays the foundation for controlling the stacking structure via atomic intercalation. These findings open up new avenues to realize intercalation-driven vdW electronic devices.
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OBJECTIVE: To explore the efficacy and safety of tandospirone for adolescents with anxiety disorder. METHODS: In this multicenter open-label 12-week study, a total of 169 adolescents met the criteria of DSM-IV for anxiety disorder were treated with flexible dose of tandospirone. The effects and safety of treatment were assessed by the Hamilton anxiety scale (HAMA), state-trait anxiety inventory (STAI), clinical global impression (CGI) and side effects at baseline and Weeks 2, 4, 8 and 12. RESULTS: In 151 cases completing the 12-week treatment, the scores of HAMA decreased by 18% ± 12%, 38% ± 16%, 54% ± 20% and 63% ± 17% at Weeks 2, 4, 8 and 12. Significant reductions in HAMA scores were seen at Weeks 2-12 (P < 0.01) and marked improvement appeared in 81.5% cases at Week 12 (reduction rate of HAMA: 50%). At Week 12, the HAMD(17) scores were markedly lower versus baseline (7 ± 2 vs 13 ± 3, P < 0.01). Adverse effect of tandospirone was scarcely found (9.9%). CONCLUSION: Tandospirone is an effective and safe anti-anxiety drug for adolescents.
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Ansiolíticos/uso terapéutico , Trastornos de Ansiedad/tratamiento farmacológico , Isoindoles/uso terapéutico , Piperazinas/uso terapéutico , Pirimidinas/uso terapéutico , Adolescente , Ansiolíticos/efectos adversos , Femenino , Humanos , Isoindoles/efectos adversos , Masculino , Piperazinas/efectos adversos , Pirimidinas/efectos adversos , Resultado del Tratamiento , Adulto JovenRESUMEN
A compact setup with a planar-cathode and grid-anode plus free field drift distance configuration (momentatron) has provided a new way to measure the transverse momentum and, hence, the emittance of the electron beam from a photocathode. This method has been used for analysis of the transverse momentum and emittance of the photoemitted electron beam from the photocathode in a stepwise manner during the fabrication process. The errors caused by the lensing effect from opening holes of the grid anode and misalignments caused by tilting and curving have been systematically analyzed. An analytical method has been developed, and a full three-dimensional electrostatic field particle tracing simulation has been performed to validate this measurement technique. The results show that a momentatron can provide an accurate measurement of transverse momentum and emittance of the photoemitted electrons. The reasonable experimental errors that may be encountered will only have a modest (few %) effect on the emittance measurement.
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We present experimental observations of high order phase contrast in aberration corrected low energy electron microscopy (AC-LEEM). Phase contrast produced by atomic steps on a Ag (111) surface exhibits prominent high order interference fringes, which have not been reported before. These phase contrast features depend upon defocus and incident electron energy, similar to the prominent first order fringes observed previously and in agreement with Fourier optics (FO) model predictions. The comparison of experimental results and FO model simulations demonstrates that fringe amplitudes are strongly affected at large defocus by the source divergence. This effect is exploited to quantitatively determine the divergence, 0.055 ± 0.005 mrad, of the field emission source in AC-LEEM under the imaging conditions used. Although the divergence determines the spatial coherence of the illumination in microscopy, it has not been possible to characterize this key instrumental parameter in LEEM before.
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Spin Polarized Low Energy Electron Microscopy (SPLEEM) is a powerful tool to reveal the magnetic structure of ferromagnetic surfaces on the atomic depth scale level[1-3]. With aberration corrected LEEM and a high brightness spin polarized electron gun, high spatial resolution will provide more details for ultra-thin ferromagnetic film studies. This study reports the first realization of aberration corrected SPLEEM (AC-SPLEEM). The performance of the setup was tested on ferromagnetic Fe nanoscale islands on a W(110) single crystal, with spatial resolution of 3.3 nm in spin asymmetry images.
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The characterization and control of atomic substitution process is crucial in fabricating high-quality two-dimensional layered compound materials and tuning their physical properties. With intensity-voltage low energy electron microscopy (IV-LEEM), we found that the concentration of copper in the topmost copper silicide monolayer on Si (111) substrates varies gradually from 1.7 to 1.0 ML while preserving it's unique '5 × 5' incommensurate phase in a transition region as large as 1000â¯nm. This gradual variation of the copper concentration is due to the incomplete substitution of the Si with Cu, as revealed by atomic-resolved scanning tunneling microscopy with a tip that nicely resolved the '5 × 5' periodicity. Our experiments indicate that besides the widely-accepted phase of Cu2Si with both substitutional and interstitial Cu atoms, another type of precursor copper silicide CuSi3 with only interstitial Cu atoms also plays important roles in the substitutional diffusion and reaction processes during the formation of the topmost copper silicide monolayer. This precursor phase might exist in the growth of other two-dimensional layered materials with potential applications in integrated optoelectronics, spintronics or low dissipative devices.
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BACKGROUND: Pediatric chronic pain is relatively common in the world. Although cognitive behavior therapy (CBT) has been shown to be efficacious in children and adolescents, it is generally recognized that availability and accessibility of CBT are limited. While Internet-delivered cognitive-behavioral therapy (ICBT) performs better in these areas. OBJECTIVES: This systematic review aims to evaluate the clinical effects of ICBT for chronic pain in youth when compared with the control treatments. METHODS: We searched electronic databases to identify randomized controlled trials that compared ICBT with the control therapy for pediatric chronic pain. The primary outcomes were 95% confidence intervals and mean difference or standardized mean difference in change of pain intensity and activity limitations. RESULTS: Four trials met the inclusion criteria with a total of 404 participants of whom 208 received ICBT. Compared with pretreatment, children reported significant, medium to large benefits on pain intensity, activity limitations, and parental protective behaviors after receiving ICBT immediately. Significant small to medium effects were found for outcomes of depressive symptoms, anxiety, and sleep quality from baseline to post-treatment in the ICBT group. But most measures of ICBT did not show statistically significant superiority to those of the control conditions, except parental protective behaviors. Generally children and their parents were highly acceptable and satisfied with ICBT. CONCLUSION: ICBT for physical and psychological conditions in youth with chronic pain is a full potential therapy; it can be successful on clinically effects and socioeconomic benefits. However, only limited data supported the conclusion, we require further methodologically robust trials. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42017069811.
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Dolor Crónico/terapia , Terapia Cognitivo-Conductual , Internet , Manejo del Dolor , Terapia Asistida por Computador , Adolescente , Niño , Humanos , Manejo del Dolor/métodos , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Van der Waals (vdW) assembly of layered materials is a promising paradigm for creating electronic and optoelectronic devices with novel properties. Ferroelectricity in vdW layered materials could enable nonvolatile memory and low-power electronic and optoelectronic switches, but to date, few vdW ferroelectrics have been reported, and few in-plane vdW ferroelectrics are known. We report the discovery of in-plane ferroelectricity in a widely investigated vdW layered material, ß'-In2Se3. The in-plane ferroelectricity is strongly tied to the formation of one-dimensional superstructures aligning along one of the threefold rotational symmetric directions of the hexagonal lattice in the c plane. Surprisingly, the superstructures and ferroelectricity are stable to 200°C in both bulk and thin exfoliated layers of In2Se3. Because of the in-plane nature of ferroelectricity, the domains exhibit a strong linear dichroism, enabling novel polarization-dependent optical properties.
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The effects of space charge, aberrations and relativity on temporal compression are investigated for a compact spherical electrostatic capacitor (α-SDA). By employing the three-dimensional (3D) field simulation and the 3D space charge model based on numerical General Particle Tracer and SIMION, we map the compression efficiency for a wide range of initial beam size and single-pulse electron number and determine the optimum conditions of electron pulses for the most effective compression. The results demonstrate that both space charge effects and aberrations prevent the compression of electron pulses into the sub-ps region if the electron number and the beam size are not properly optimized. Our results suggest that α-SDA is an effective compression approach for electron pulses under the optimum conditions. It may serve as a potential key component in designing future time-resolved electron sources for electron diffraction and spectroscopy experiments.
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We describe the design and commissioning of a novel aberration-corrected low energy electron microscope (AC-LEEM). A third magnetic prism array (MPA) is added to the standard AC-LEEM with two prism arrays, allowing the incorporation of an ultrafast spin-polarized electron source alongside the standard cold field emission electron source, without degrading spatial resolution. The high degree of symmetries of the AC-LEEM are utilized while we design the electron optics of the ultrafast spin-polarized electron source, so as to minimize the deleterious effect of time broadening, while maintaining full control of electron spin. A spatial resolution of 2nm and temporal resolution of 10ps (ps) are expected in the future time resolved aberration-corrected spin-polarized LEEM (TR-AC-SPLEEM). The commissioning of the three-prism AC-LEEM has been successfully finished with the cold field emission source, with a spatial resolution below 2nm.
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Thioredoxin (Trx) is a member of the thioredoxin protein family and has a conserved catalytic domain (-Trp-Cys-Gly-Pro-Cys-Lys-) with reduction/oxidation (redox) activity. There are two main members in this family, Trx-1, a cytosolic and nuclear form, and Trx -2, a mitochondrial form. Trx-1 is a 104 amino acid multifunctional protein that has been extensively studied. Here we report the preparation of monoclonal antibodies (MAb) against recombinant human Trx-1(hTrx). To enhance its immunogenicity, Trx-1 was coupled to carrier protein bovine serum albumin by a two-step glutaraldehyde method. Using conventional procedures, we prepared three stable hybridoma cell lines that can produce and secret anti-Trx MAbs. We further analyzed their isotypes, titer, and affinity and found that those MAbs belong to the G1 subclass with kappa light chains, respectively. The MAbs were capable of recognizing hTrx-1, as determined by Western blotting.
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Anticuerpos Monoclonales/biosíntesis , Proteínas Recombinantes/inmunología , Tiorredoxinas/inmunología , Animales , Bovinos , Fusión Celular , Línea Celular , Línea Celular Tumoral , Humanos , Hibridomas , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia MolecularRESUMEN
Monoclonal antibodies (MAbs) against insulin are useful for insulin assays because of their specificity and plentiful supply. We have produced four monoclonal cell strains stably secreting the monoclonal antibodies against insulin; further established subpopulation, titer, affinity; and identified the antibodies as being of subclass IgG(2b)(kappa), one strain, or IgG(1)(kappa), three strains. The smallest detectable level of human insulin by ELISA using this IgG(1) was 1.25 microg/L. The monoclonal antibodies have been used for analyzing insulin content from the sera of type 2 diabetes patients and normal subjects.
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Anticuerpos Monoclonales/biosíntesis , Insulina/inmunología , Animales , Bovinos , Diabetes Mellitus Tipo 2/sangre , Ensayo de Inmunoadsorción Enzimática/métodos , Humanos , Hibridomas/inmunología , Inmunoglobulina G/biosíntesis , Insulina/sangre , Ratones , Ratones Endogámicos BALB CRESUMEN
Different cell line with increased thioredoxin-1 (Trx-1) showed a decreased or increased sensitivity to cell killing by cisplatin. Recently, several studies found that the subcellular localization of Trx-1 is closely associated with its functions. In this study, we explored the association of the nuclear Trx-1 with the cisplatin-mediated apoptosis of breast cancer cells MCF-7. Firstly, we found that higher total Trx-1 accompanied by no change of nuclear Trx-1 can not influence apoptosis induced by cisplatin in MCF-7 cells transferred with Trx-1 cDNA. Secondly, higher nuclear Trx-1 accompanied by no change of total Trx-1 can protect cells from apoptosis induced by cisplatin. Thirdly, high nuclear Trx-1 involves in the cisplatin-resistance in cisplatin-resistive cells. Meanwhile, we found that the mRNA level of p53 is closely correlated with the level of nuclear Trx-1. In summary, we concluded that the nuclear Trx-1 is required to resist apoptosis of MCF-7 cells induced by cisplatin, probably through up-regulating the anti-apoptotic gene, p53.
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Apoptosis/efectos de los fármacos , Núcleo Celular/metabolismo , Cisplatino/farmacología , Tiorredoxinas/metabolismo , Apoptosis/efectos de la radiación , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Núcleo Celular/efectos de la radiación , Resistencia a Antineoplásicos/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de la radiación , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Humanos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Rayos UltravioletaRESUMEN
Daintain is a 17-kDa polypeptide originally purified from porcine intestine. This polypeptide is associated with insulin secretion and inflammatory responses. Daintain is highly similar in amino acid sequence to allograft inflammatory factor-1 (AIF-1). Here we report the preparation and identification of monoclonal antibodies (MAbs) against daintain. To enhance its immunogenicity, daintain was coupled to carrier protein bovine serum albumin (BSA) by a two-step glutaraldehyde method. Using conventional procedures, we obtained four stable hybridoma cell lines that can produce and secret anti-daintain MAbs. We further analyzed their isotypes, titer, and affinity, and found that those MAbs belong to the G1 subclass with kappa light chains. The MAbs were capable of recognizing daintain as determined by Western blotting. The produced MAbs will be a useful tool for further investigation of daintain functions in organisms.