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1.
Nat Commun ; 15(1): 3133, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605052

RESUMO

Bernal bilayer graphene (BLG) offers a highly flexible platform for tuning the band structure, featuring two distinct regimes. One is a tunable band gap induced by large displacement fields. Another is a gapless metallic band occurring at low fields, featuring rich fine structure consisting of four linearly dispersing Dirac cones and van Hove singularities. Even though BLG has been extensively studied experimentally, the evidence of this band structure is still elusive, likely due to insufficient energy resolution. Here, we use Landau levels as markers of the energy dispersion and analyze the Landau level spectrum in a regime where the cyclotron orbits of electrons or holes in momentum space are small enough to resolve the distinct mini Dirac cones. We identify the presence of four Dirac cones and map out topological transitions induced by displacement field. By clarifying the low-energy properties of BLG bands, these findings provide a valuable addition to the toolkit for graphene electronics.

2.
CNS Neurosci Ther ; 30(2): e14611, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38353051

RESUMO

AIMS: Basolateral amygdala (BLA), as a center for stress responses and emotional regulation, is involved in visceral hypersensitivity of irritable bowel syndrome (IBS) induced by stress. In the present study, we aimed to investigate the role of EphB2 receptor (EphB2) in BLA and explore the underlying mechanisms in this process. METHODS: Visceral hypersensitivity was induced by water avoidance stress (WAS). Elevated plus maze test, forced swimming test, and sucrose preference test were applied to assess anxiety- and depression-like behaviors. Ibotenic acid or lentivirus was used to inactivate BLA in either the induction or maintenance stage of visceral hypersensitivity. The expression of protein was determined by quantitative PCR, immunofluorescence, and western blot. RESULTS: EphB2 expression was increased in BLA in WAS rats. Inactivation of BLA or downregulation of EphB2 in BLA failed to induce visceral hypersensitivity as well as anxiety-like behaviors. However, during the maintenance stage of visceral pain, visceral hypersensitivity was only partially relieved but anxiety-like behaviors were abolished by inactivation of BLA or downregulation of EphB2 in BLA. Chronic WAS increased the expression of EphB2, N-methyl-D-aspartate receptors (NMDARs), and postsynaptic density protein (PSD95) in BLA. Downregulation of EphB2 in BLA reduced NMDARs and PSD95 expression in WAS rats. However, activation of NMDARs after the knockdown of EphB2 expression still triggered visceral hypersensitivity and anxiety-like behaviors. CONCLUSIONS: Taken together, the results suggest that EphB2 in BLA plays an essential role in inducing visceral hypersensitivity. In the maintenance stage, the involvement of EphB2 is crucial but not sufficient. The increase in EphB2 induced by WAS may enhance synaptic plasticity in BLA through upregulating NMDARs, which results in IBS-like symptoms. These findings may give insight into the treatment of IBS and related psychological distress.


Assuntos
Complexo Nuclear Basolateral da Amígdala , Síndrome do Intestino Irritável , Dor Visceral , Animais , Ratos , Complexo Nuclear Basolateral da Amígdala/metabolismo , Síndrome do Intestino Irritável/metabolismo , Síndrome do Intestino Irritável/psicologia , Ratos Sprague-Dawley , Receptor EphB2/metabolismo , Estresse Psicológico/psicologia , Dor Visceral/metabolismo , Água/metabolismo
3.
Microbiol Spectr ; 12(3): e0384623, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38299831

RESUMO

Acidovorax citrulli is the main pathogen causing bacterial fruit blotch, which seriously threatens the global watermelon industry. At present, rapid, sensitive, and low-cost detection methods are urgently needed. The established CRISPR/LbCas12a visual detection method can specifically detect A. citrulli and does not cross-react with other pathogenic bacteria such as Erwinia tracheiphila, Pseudomonas syringae, and Xanthomonas campestris. The sensitivity of this method for genomic DNA detection is as low as 0.7 copies/µL, which is higher than conventional PCR and real-time PCR. In addition, this method only takes 2.5 h from DNA extraction to quantitative detection and does not require complex operation and sample treatment. Additionally, the technique was applied to test real watermelon seed samples for A. citrulli, and the results were contrasted with those of real-time fluorescence quantitative PCR and conventional PCR. The high sensitivity and specificity have broad application prospects in the rapid detection of bacterial fruit blotch bacterial pathogens of watermelon.IMPORTANCEBacterial fruit blotch, Acidovorax citrulli, is an important seed-borne bacterial disease of watermelon, melon, and other cucurbits. The lack of rapid, sensitive, and reliable pathogen detection methods has hampered research on fruit spot disease prevention and control. Here, we demonstrate the CRISPR/Cas12a system to analyze aspects of the specificity and sensitivity of A. citrulli and to test actual watermelon seed samples. The results showed that the CRISPR/Cas12a-based free-amplification method for detecting bacterial fruit blotch pathogens of watermelons was specific for A. citrulli target genes and 100-fold more sensitive than conventional PCR with quantitative real-time PCR. This method provides a new technical tool for the detection of A. citrulli.


Assuntos
Citrullus , Comamonadaceae , Citrullus/genética , Citrullus/microbiologia , Frutas/microbiologia , Doenças das Plantas/microbiologia , Comamonadaceae/genética , DNA
4.
Science ; 383(6678): 42-48, 2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38175887

RESUMO

Quantum oscillations originating from the quantization of electron cyclotron orbits provide sensitive diagnostics of electron bands and interactions. We report on nanoscale imaging of the thermodynamic magnetization oscillations caused by the de Haas-van Alphen effect in moiré graphene. Scanning by means of superconducting quantum interference device (SQUID)-on-tip in Bernal bilayer graphene crystal axis-aligned to hexagonal boron nitride reveals large magnetization oscillations with amplitudes reaching 500 Bohr magneton per electron in weak magnetic fields, unexpectedly low frequencies, and high sensitivity to superlattice filling fraction. The oscillations allow us to reconstruct the complex band structure, revealing narrow moiré bands with multiple overlapping Fermi surfaces separated by unusually small momentum gaps. We identified sets of oscillations that violate the textbook Onsager Fermi surface sum rule, signaling formation of broad-band particle-hole superposition states induced by coherent magnetic breakdown.

5.
Proc Natl Acad Sci U S A ; 120(39): e2305943120, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37738298

RESUMO

Different superconducting pairing mechanisms are markedly distinct in the underlying Cooper pair kinematics. Quantum-critical soft modes drive pairing interactions in which the pair scattering processes are highly collinear and can be classified into two categories: forward scattering and backscattering. Conversely, in conventional phonon mechanisms, Cooper pair scattering is of a generic noncollinear character. In this study, we present a method to discern the kinematic type by observing the evolution of superconductivity while adjusting the Fermi surface geometry. To demonstrate our approach, we utilize the recently reported phase diagrams of untwisted graphene multilayers. Our analysis connects the emergence of superconductivity at "ghost crossings" of Fermi surfaces in distinct valleys to the pair kinematics of a backscattering type. Together with the observed nonmonotonic behavior of superconductivity near its onset (sharp rise followed by a drop), it lends strong support to a particular quantum-critical superconductivity scenario in which pairing is driven by intervalley coherence fluctuations. These findings offer direct insights into the genesis of pairing in these systems, providing compelling evidence for the electron-electron interactions driving superconductivity. More broadly, our work highlights the potential of tuning bands via ghost crossings as a promising means of boosting superconductivity.

6.
J Clin Gastroenterol ; 2023 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-37732730

RESUMO

BACKGROUND AND AIMS: Recently, the location-based resect-and-discard (LBRD) strategy, which does not depend on optical diagnosis, was developed and demonstrated different surveillance interval agreement with the pathology-based reference in several researches. We aimed to evaluate the performance of LBRD in our first-time colonoscopy cohort, and improve the LBRD. METHODS: The first-time colonoscopy with complete pathologic information were enrolled. The accuracy of LBRD strategy applied in diminutive polyps in different colonic segments was used as indicator to develop modified LBRD (mLBRD) strategy. Surveillance interval agreement with pathology-based reference was compared between LBRD and mLBRD. The ≥ 90% agreement with pathology was used as benchmark. RESULTS: The polyps in sigmoid colon were significantly associated with higher proportion of neoplastic compared with polyps in rectum. The accuracy of LBRD applied in polyps in sigmoid colon were only 53.5%, which was significantly lower than that applied in polyps in other colonic segments. Thus, we hypothesized that mLBRD requiring pathology examination of diminutive polyps in sigmoid colon was more efficient in clinical use. The mLBRD significantly outperformed LBRD in surveillance interval agreement with pathology-based reference (90.2% vs. 83.4%, P<0.001), had lower proportion of patients assigned a longer surveillance interval (3.6% vs. 10.5%, P<0.001) and reached the benchmark, although the proportion of patients with an immediate surveillance interval recommendations and pathology examination avoided decreased. CONCLUSIONS: The mLBRD, but not LBRD, achieved sufficient surveillance interval agreement with pathology-based surveillance interval assignment and reduced over 30% of pathology examinations.

7.
J Environ Radioact ; 270: 107284, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37634424

RESUMO

The surface isotope radon measurement method (SIRMM) is widely used in fire source detection in abandoned mines. However, studies on the long-distance migration of radon during coal spontaneous combustion are lacking, which hinders the further popularization of this technology in coal fire prevention and control. For this reason, the migration law of radon in overlying strata in fire areas was studied through experiments and numerical simulation. The radon exhalation concentration of coal was found to increase at first and then decrease in the range of 30-350 °C through experiments. The radon concentration reaches the maximum value (557.1 Bq/m3) at 150 °C, which is 6.3 times higher than that at 30 °C. Based on the radon source term obtained by fitting the experimental data, the radon migration model of coal spontaneous combustion in abandoned goaf was constructed, and the dynamic distribution characteristics of the airflow, temperature, and radon concentration fields in the overlying strata area were analyzed. The internal relationship between surface radon and underground fire source was discussed. The simulation results revealed the sharp change in the porosity of the overlying rock causes radon concentration at the interface between the caving and fissure zones to increase continually with the process of spontaneous combustion, providing material and energy support for the long-distance radon migration. When the maximum temperature of the coal pile reaches 70 °C, the concentration of radon released from the coal pile increases rapidly to 13696 Bq/m3, and the radon from the underground space appears on the surface at this temperature. In the range of 70-150 °C, with rapid increase in radon released from coal piles, the surface concentration of radon also increased rapidly to 225 Bq/m3. At the high-temperature stage exceeding 150 °C, the concentration of radon released from coal piles exhibited a downward trend, resulting in a decrease in the rate of increase of radon concentration on the surface. A close relationship between the surface radon concentration and underground fire source temperature in the process of coal spontaneous combustion was observed. In the spatial position, the peak position of radon on the surface was highly consistent with that of the fire source longitudinally, which ensures the accuracy of the SIRMM to determine the location of the hidden fire source. This suggests that the SIRMM can accurately evaluate the fire source's temperature and fire area's development trend.


Assuntos
Minas de Carvão , Incêndios , Monitoramento de Radiação , Radônio , Radônio/análise , Combustão Espontânea , Carvão Mineral/análise , Monitoramento de Radiação/métodos , Incêndios/prevenção & controle
8.
Phys Rev Lett ; 130(20): 206701, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37267555

RESUMO

We argue that spin- and valley-polarized metallic phases recently observed in graphene bilayers and trilayers support chiral edge modes that allow spin waves to propagate ballistically along system boundaries without backscattering. The chiral edge behavior originates from the interplay between the momentum-space Berry curvature in Dirac bands and the geometric phase of a spin texture in position space. The edge modes are weakly confined to the edge, featuring dispersion that is robust and insensitive to the detailed profile of magnetization at the edge. This unique character of edge modes reduces their overlap with edge disorder and enhances the mode lifetime. The mode propagation direction reverses upon reversing valley polarization, an effect that provides a clear testable signature of geometric interactions in isospin-polarized Dirac bands.

9.
ACS Omega ; 8(9): 8683-8694, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36910988

RESUMO

A FeMnCe-activated semi-coke catalyst (FeMnCe/ASC) was prepared by the co-precipitation method using semi-coke as the raw material. The structure and morphology were characterized by X-ray diffraction, Brunauer-Emmett-Teller, scanning electron microscopy, and transmission electron microscopy analyses. The catalytic activity and stability of the FeMnCe/ASC catalyst were investigated with piperazine as the target degradation pollutant and ammonia nitrogen and chemical oxygen demand (COD) as the evaluation indexes. The results showed that the average pore size of FeMnCe/ASC mesopores was 6.68 nm, and the active components were uniformly dispersed on the carrier surface. Under the optimum conditions of piperazine solution including a mass concentration of 100 mg/L, a catalyst mass concentration of 4.0 g/L, a reaction temperature of 240 °C, an oxygen partial pressure of 1.2 MPa, a stirring speed of 500 rpm, and a reaction time of 120 min, the degradation rates of both ammonia nitrogen and COD reached 100%. After the catalyst was recycled five times, the degradation rates of ammonia nitrogen and COD still reached more than 90%. The elemental valence changes before and after the reaction were analyzed by X-ray photoelectron spectroscopy, and the intermediate products generated from piperazine degradation were analyzed by gas chromatography-mass spectroscopy to evaluate the mechanism of piperazine degradation and speculate about the degradation pathway of piperazine.

10.
ACS Omega ; 8(1): 1476-1485, 2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36643557

RESUMO

The threshold dilution ratio of acetaldehyde is much larger than those of other odor compounds generated during the spontaneous combustion process and so it is the most important odorant. Studying the mechanism by which acetaldehyde is generated can provide the necessary theoretical support for acetaldehyde-based odor analysis. In the present work, the release of acetaldehyde was monitored while heating lignite, long-flame coal, and coking coal specimens under either air or nitrogen. The data show that acetaldehyde was primarily produced by the oxidation of active sites in the coal rather than by the pyrolysis of oxygen-containing functional groups. Based on quantum chemistry and coal-oxygen reaction theory, the transition state approach was used to further study the formation of acetaldehyde during the low-temperature oxidation of coal. Using density functional theory, three different coal molecule structures were modeled and optimized structures for acetaldehyde formation and the energies, bond lengths, and virtual frequencies of each reaction stagnation point were obtained at the B3LYP-D3/6-311G** and M062X-D3/Def2-TZVP levels. The results indicate that the low-temperature oxidation of coal to generate acetaldehyde involves the capture of H atoms from aliphatic side chains to generate peroxy radicals. These radicals then attack unsaturated C atoms through complex inversions to generate peroxides. In the third step of this process, the O-O single bonds in the peroxides break in response to thermal energy to form carbonyl groups. Finally, specific C-C or C-O bonds on the aliphatic side chains are thermally cleaved to generate acetaldehyde.

11.
Front Public Health ; 10: 1076461, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36483258

RESUMO

Prefabricated construction is one of the solutions to the problem of balancing environmental improvements with the new buildings in the construction industry. Some work originally done on site is transferred to the front end, and the occupational health risks to industrial workers during the production of prefabricate concrete components are thus aggravated. This study aims to propose a framework to simulate the occupational health risks of workers in prefabricate concrete component plants from the perspective of risk identification, risk assessment, and risk control. Through the following 4 steps, including environmental release monitoring, diffusion and human inhalation mechanism analysis, occupational health risk evaluation, and full-path health risk simulation, this study maps physical entities to virtual reality. The proposed method tends to address the root causes behind occupational health risks, such as the lack of measurement, assessment and prevention criteria, and providing new ideas for theoretical research and innovative practice of HSE management and risk management in the construction industry.


Assuntos
Saúde Ocupacional , Humanos
12.
Artigo em Inglês | MEDLINE | ID: mdl-36078249

RESUMO

It has been more than two years since the outbreak of the COVID-19 epidemic at the end of 2019. Many scholars have introduced the "resilience" concept into COVID-19 prevention and control to make up for the deficiencies in traditional community governance. This study analyzed the progress in research on social resilience, which is an important component of community resilience, focusing on the current literature on the impact of social resilience on COVID-19, and proposed a generalized dimension to integrated previous relevant literature. Then, VOSviewer was used to visualize and analyze the current progress of research on social resilience. The PRISMA method was used to collate studies on social resilience to the pandemic. The result showed that many current policies are effective in controlling COVID-19, but some key factors, such as vulnerable groups, social assistance, and socioeconomics, affect proper social functioning. Some scholars have proposed effective solutions to improve social resilience, such as establishing an assessment framework, identifying priority inoculation groups, and improving access to technology and cultural communication. Social resilience to COVID-19 can be enhanced by both external interventions and internal regulation. Social resilience requires these two aspects to be coordinated to strengthen community and urban pandemic resilience.


Assuntos
COVID-19 , Resiliência Psicológica , COVID-19/epidemiologia , Surtos de Doenças , Humanos , Pandemias/prevenção & controle , Fatores Socioeconômicos
13.
Front Cell Neurosci ; 16: 922750, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36072567

RESUMO

Tandospirone, a third-generation of antianxiety agent with fewer side effects, has been widely used in the treatment of anxiety. Moreover, it is interesting that tandospirone has been found to relieve gastrointestinal symptoms in patients with refractory irritable bowel syndrome who also have psychological dysfunctions. However, the underlying mechanism remains unclear. In this study, using a visceral hypersensitivity rat model induced by chronic water avoidance stress to mimic the symptoms of irritable bowel syndrome, we found that tandospirone relieved anxiety-like behavior and visceral hypersensitivity induced by stress. Meanwhile, stressed rats had increased 5-HT concentration, less 5-HT1A receptor expression, and enhanced theta oscillations in the anterior cingulate cortex (ACC). Furthermore, the power of the theta band in ACC is positively correlated with the level of visceral sensitivity. Activation of 5-HT1A receptors by its agonist, 8-OH-DPAT, to compensate for their effect in ACC reduced the enhancement of theta oscillations in ACC slices in stressed rats, whereas 5-HT1A receptor antagonist, WAY100135, facilitates theta oscillations in slices of normal rats. Tandospirone reduced the enhancement of theta band power in ACC in vitro and in vivo, thus alleviating anxiety-like behavior and visceral hypersensitivity through 5-HT1A receptors in stressed rats. These results suggest a novel mechanism by which tandospirone activates 5-HT1A receptors to relieve stress-induced anxiety and visceral hypersensitivity by suppressing theta oscillation enhancement in ACC.

14.
J Pain ; 23(11): 1973-1988, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35914642

RESUMO

The rostral anterior cingulate cortex (rACC) has been found to be an important brain region in mediating visceral hypersensitivity. However, the underlying mechanisms remain unclear. This study aimed to explore the role of astrocytes in the maintenance of visceral hypersensitivity induced by chronic water avoidance stress (WAS) as well as the potential signaling pathway that activates astrocytes in the rACC. We found that ACC-reactive astrogliosis resulted in the overexpression of c-fos, TSP-1, and BDNF in stress-related visceral hypersensitivity rats. Visceral hypersensitivity was reversed by pharmacological inhibition of astrocytic activation after WAS, as were the overexpression of c-fos, TSP-1 and BDNF. Activation of the astrocytic Gi-pathway increased the visceral sensitivity and expression of c-fos, TSP-1, and BDNF. Visceral hypersensitivity was also ameliorated by the pharmacological inhibition of ERK and STAT1 phosphorylation after WAS. Furthermore, inhibition of the ERK-STAT1 cascade reduced astrocytic activation. These findings suggest that astrocytic ERK/STAT1 signaling in the rACC contributes to the maintenance of stress-related visceral hypersensitivity. PERSPECTIVE: Visceral hypersensitivity is a key factor in the pathophysiology of irritable bowel syndrome. This study highlights the important role of astrocytic ERK/STAT1 signaling in activating astrocytes in the rostral anterior cingulate cortex, which contributes to visceral hypersensitivity.


Assuntos
Astrócitos , Dor Visceral , Ratos , Animais , Astrócitos/metabolismo , Trombospondina 1/metabolismo , Ratos Sprague-Dawley , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Transdução de Sinais/fisiologia , Fator de Transcrição STAT1/metabolismo
15.
Front Mol Neurosci ; 15: 908911, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35966013

RESUMO

Early adverse life events (EALs), such as maternal separation (MS), can cause visceral hypersensitivity, which is thought to be a key pathophysiological mechanism of irritable bowel syndrome (IBS). Previous studies mainly focused on EALs-induced visceral hypersensitivity in adulthood but did not consider that it may have occurred in the preadult period. We previously found that rats who experienced MS suffered from visceral hypersensitivity starting from the post-weaning period. Moreover, the hippocampus is considered to be critical in regulating the formation of visceral hypersensitivity induced by MS. But the underlying mechanisms throughout different life periods are unclear. In this study, behavioral tests, RNA-seq, lentiviral interference, and molecular biology techniques were applied to investigate the molecular mechanism in the hippocampus underlying MS-induced long-lasting visceral hypersensitivity. It was found that both visceral sensitivity and anxiety-like behaviors were significantly increased in MS rats in post-weaning, prepubertal, and adult periods, especially in the prepubertal period. Subsequently, RNA-seq targeting the hippocampus identified that the expression level of Netrin-1 was significantly increased in all periods, which was further confirmed by quantitative real-time PCR and Western blot. Knocking-down hippocampal Netrin-1 in the post-weaning period by lentivirus interference alleviated visceral hypersensitivity and anxiety-like behaviors of MS rats in the later phase of life. In addition, deleted in colorectal cancer (DCC), instead of neogenin-1(Neo-1) or uncoordinated (UNC5), was proved to be the specific functional receptor of Netrin-1 in regulating visceral hypersensitivity, whose upregulation may result in the most severe symptoms in the prepubertal period. Furthermore, the activation of the Netrin-1/DCC pathway could enhance long-term potentiation (LTP) in the hippocampus, probably via recruitment of the AMPA receptor subunit GluA1, which finally resulted in the formation of visceral hypersensitivity. These novel findings suggest that long-lasting over-expression of Netrin-1 can mediate visceral hypersensitivity and anxiety disorder from the post-weaning period to adulthood by activating DCC/GluA1 pathway in the hippocampus. Moreover, early intervention of Netrin-1 in the post-weaning period could lead to significant symptom relief afterward, which provides evidence that the Netrin-1/DCC/GluA1 signaling pathway may be a potential therapeutic target for the treatment of visceral hypersensitivity in clinics.

16.
Ther Clin Risk Manag ; 18: 561-569, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602262

RESUMO

Purpose: To identify pathology discrepancy between forceps biopsies and polypectomy specimens in colorectal polyps, as well as the reliability of biopsy-based treatment strategy. Methods: All endoscopic polypectomy cases with forceps biopsies performed within 6 months were included in the study. The biopsies were compared with polypectomy specimens in terms of concordance of histological diagnosis. A logistic regression model was used to investigate the independent predictors of upgrade in histological diagnosis compared with concordance in histological diagnosis. Results: A total of 1686 paired screening-therapeutic colonoscopies and 1739 paired biopsy-polypectomy specimens were enrolled in the study. The grade of dysplasia in 84.5% of biopsy specimens were concordant to polypectomy specimens, but this proportion decreased to 75.4% when the specimens were classified using tubular or villousness structure. 10.1% and 5.4% of biopsy specimens were upgraded and downgraded in assessing grade of dysplasia, respectively, while 14.3% and 10.3% of biopsy specimens were upgraded and downgraded in assessing tubular or villousness structure, respectively. In subgroup analysis stratified by size of polyps, 9.0% and 10.6% of biopsies obtained from polyps smaller than 10 mm were upgraded in assessing dysplasia and tubular or villousness structure, respectively. This proportion increased to 10.7% and 21.3%, respectively, in biopsies obtained from polyps larger than 10 mm. Larger size of polyps and pedunculated polyps were associated with a higher incidence of upgrade in histological diagnosis. Nearly 25% of biopsy specimens with high-grade dysplasia were identified as adenocarcinoma in polypectomy specimens. Conclusion: The concordance between biopsy and polypectomy specimens is not adequate. The biopsy-based treatment strategy is not reliable and should not be considered as an indicator for further treatment, particularly in large or pedunculated polyps.

17.
Gastroenterol Res Pract ; 2022: 4145810, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35386530

RESUMO

Objective: Effective therapies for reflux hypersensitivity are lacking. Endoscopic radiofrequency ablation may reduce the sensitivity of the distal esophagus through direct interference with nociceptors or vagal afferent fibers and thus may be useful in reflux hypersensitivity. The aim of this study is to assess the effectiveness and possible mechanisms of endoscopic radiofrequency ablation in reflux hypersensitivity patients. Methods: Patients with reflux hypersensitivity who fulfilled the Rome IV criteria and who wished to receive further treatment were recruited. Endoscopic radiofrequency ablation was delivered to the gastroesophageal junction. Data were collected by questionnaire using a 6-point Likert scale. The primary outcome measure was effect on symptoms including heartburn, regurgitation, and chest pain. The secondary outcomes were degree of satisfaction, medication use, acid exposure time (AET), low esophageal sphincter (LES) pressure, and total reflux episodes. We also assessed positive cell density of transient receptor potential vanilloid type 1 receptor (TRPV1) and calcitonin gene-related peptide (CGRP), both of which are biomarkers of afferent fibers, in biopsies obtained from esophageal mucosa 0.5 cm-1 cm above the Z line. These scales will be administered at baseline, 3-month follow-up, 6-month follow-up, and 12-month follow-up. Results: A total of 22 reflux hypersensitivity patients were enrolled (14 males, median age 50.0 years). A significant improvement in symptom scores (heartburn, regurgitation, and chest pain) was noted at 3 months, 6 months, and 12 months (P < 0.001). Satisfaction with life increased to 72.7% (16/22), 72.7% (16/22), and 68.2% (15/22) at 3, 6, and 12 mo, respectively, compared with baseline (P < 0.001). Nineteen patients reduced their medication use after treatment. Of these, 22.7% (5/22), 31.8% (7/22), and 40.9% (9/22) subjects stopped medication use at 3 mo, 6 mo, and 12 mo, respectively. No statistical differences were noted in AET, LES pressure, or total reflux episodes from preoperation to 12 mo postoperation. After treatment, the positive cell density of both TRPV1 and CGRP decreased significantly; however, only TRPV1 had a positive correlation with heartburn (r = 0.51, P = 0.03) and chest pain (r = 0.77, P < 0.01). Conclusion: Endoscopic radiofrequency ablation was an effective and safe therapeutic option in reflux hypersensitivity patients. Further studies with large sample size are required to validate the role of radiofrequency in reflux hypersensitivity.

18.
Science ; 375(6579): 430-433, 2022 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-35084955

RESUMO

In thermodynamic equilibrium, current in metallic systems is carried by electronic states near the Fermi energy, whereas the filled bands underneath contribute little to conduction. Here, we describe a very different regime in which carrier distribution in graphene and its superlattices is shifted so far from equilibrium that the filled bands start playing an essential role, leading to a critical-current behavior. The criticalities develop upon the velocity of electron flow reaching the Fermi velocity. Key signatures of the out-of-equilibrium state are current-voltage characteristics that resemble those of superconductors, sharp peaks in differential resistance, sign reversal of the Hall effect, and a marked anomaly caused by the Schwinger-like production of hot electron-hole plasma. The observed behavior is expected to be common to all graphene-based superlattices.

19.
J Gastrointestin Liver Dis ; 30(3): 358-365, 2021 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-34551036

RESUMO

BACKGROUND AND AIMS: There is still considerable controversy surrounding the relationship between fatigue of endoscopists and the quality of colonoscopy. The aim of this study is to comprehensively explore the association between fatigue and adenoma detection rate (ADR) and cecal intubation rate (CIR). METHODS: The mixed effects logistic regression model was used to explore the relationship between fatigue- related factors including procedure order, session of procedures and the day of week and ADR as well as CIR. RESULTS: When controlling for confounders, the day of week (Monday as reference, Friday, p=0.022; weekends, p=0.015) and session of procedures (P<0.001) were significantly associated with ADR while procedure order (<5 as reference, 6-10, p<0.001; >10, p=0.001) and session of procedures (p=0.004) were independent predictors for CIR. Additionally, there was a significant downward trend on ADR and CIR with the approaching of weekends (p=0.005) and increasing procedure orders (p<0.001), respectively. In the subgroup analysis stratified by gender, age and workload intensity, significant lower ADR was found in the afternoon in all subgroups (male, p<0.001; female, p=0.005; <40 years, p<0.001; ≥40 years, p=0.020; intensity<50 per month, p=0.017; intensity≥50 per month, p<0.001) but the downward trend on ADR as the week progressed was only found in endoscopists with male gender (p=0.011), age<40 (p=0.027) and high workload intensity (p=0.003). Moreover, a significant downward trend on CIR as the procedure order increased was found in all subgroups except endoscopists with age≥40 (male, p=0.005; female, p<0.001; <40 years, p<0.001; intensity<50 per month, p=0.001; intensity≥50 per month, p<0.001). CONCLUSIONS: Colonoscopies in the afternoon will affect ADR negatively while increasing procedure order will cause a lower CIR. Importantly, the significant negative influence of Friday and weekends on ADR was first discovered in this study. Moreover, endoscopists with female gender and advanced age (≥40) but not high workload intensity showed superiority in resistance of fatigue caused by the end of the week and increasing daily procedures.


Assuntos
Adenoma , Esgotamento Profissional , Colonoscopia/normas , Neoplasias Colorretais , Fadiga , Adenoma/diagnóstico por imagem , Adulto , Neoplasias Colorretais/diagnóstico por imagem , Feminino , Humanos , Masculino , Programas de Rastreamento
20.
Phys Rev Lett ; 126(25): 256803, 2021 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-34241524

RESUMO

Achieving Bloch oscillations of free carriers under a direct current, a long-sought-after collective many-body behavior, has been challenging due to stringent constraints on the band properties. We argue that the flat bands in moiré graphene fulfill the basic requirements for observing Bloch oscillations, offering an appealing alternative to the stacked quantum wells used in previous work aiming to access this regime. Bloch-oscillating moiré superlattices emit a comblike spectrum of incommensurate frequencies, a property of interest for converting direct currents into high-frequency currents and developing broadband amplifiers in terahertz domain. The oscillations can be synchronized through coupling to an oscillator mode in a photonic or plasmonic resonator. Phase-coherent collective oscillations in the resonant regime provide a realization of current-pumped terahertz lasing.

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