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1.
World Neurosurg ; 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32058118

RESUMO

Angioleiomyoma is a kind of benign soft tissue tumor that manifests as pain and is more common in the extremities. However, primary intracranial angioleiomyoma is an extremely rare entity with poor clinical, radiological, and histopathological characterization. We will compile and examine reported cases of intracranial angioleiomyoma in an attempt to provide an up-to-date summary of the condition. A literature search was performed using PubMed with specific key terms. Selected case studies and case series were then compared, and statistical analyses were performed where appropriate. We report a 59-year-old woman presenting with epileptic seizures and a 2-month history of progressive headache. Magnetic resonance imaging(MRI) of the brain revealed a right temporal pole tumor, near the right cavernous sinus. Gross total resection was performed. Histopathological and immunohistochemical examination revealed an angioleiomyoma. No adjuvant radiation or chemotherapy was administered. MRI of the brain performed at a 6-month follow-up showed no signs of recurrence. Primary intracranial angioleiomyoma is an exceedingly rare central nervous system tumor. The clinical and radiological manifestations are nonspecific. The diagnosis depends on the histopathological and immunohistochemical examination. For patients with clinical symptoms,surgical resection should be the first-choice treatment.

2.
Microbes Infect ; 22(2): 86-91, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32088333

RESUMO

Only a month after the outbreak of pneumonia caused by 2019-nCoV, more than forty-thousand people were infected. This put enormous pressure on the Chinese government, medical healthcare provider, and the general public, but also made the international community deeply nervous. On the 25th day after the outbreak, the Chinese government implemented strict traffic restrictions on the area where the 2019-nCoV had originated-Hubei province, whose capital city is Wuhan. Ten days later, the rate of increase of cases in Hubei showed a significant difference (p = 0.0001) compared with the total rate of increase in other provinces of China. These preliminary data suggest the effectiveness of a traffic restriction policy for this pandemic thus far. At the same time, solid financial support and improved research ability, along with network communication technology, also greatly facilitated the application of epidemic prevention measures. These measures were motivated by the need to provide effective treatment of patients, and involved consultation with three major groups in policy formulation-public health experts, the government, and the general public. It was also aided by media and information technology, as well as international cooperation. This experience will provide China and other countries with valuable lessons for quickly coordinating and coping with future public health emergencies.


Assuntos
Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Epidemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Animais , China , Quirópteros/virologia , Comunicação , Governo , Humanos , Saúde Pública/métodos , Viagem , Zoonoses/virologia
3.
Front Genet ; 10: 531, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275351

RESUMO

Background: Diabetic retinopathy (DR) is a common diabetes complication and was considered as the major cause of blindness among young adults. MiRNAs are a group of small non-coding RNAs regulating the expression of target genes and have been reported to be associated with the development of DR in a variety of molecular mechanisms. In this study, we aimed to identify miRNAs that are differentially expressed (DE) in the serum of DR patients. Methods: We recruited 21 type 2 diabetes mellitus (T2DM) inpatients of Chinese Han ancestry, consisting of 10 non-proliferative DR patients (DR group) and 11 non-DR T2DM patients (NDR group). MiRNA was extracted from fasting peripheral serum and quantified by RNA-seq. The expression levels of miRNA were evaluated and compared between the two groups, with adjustments made for age differences. The validated target genes of miRNAs were subjected to a pathway analysis. We also constructed a weighted polygenic risk score using the DE miRNA and evaluated its predictive power. Results: Five miRNAs were DE between DR and NDR groups (p-Value ≤ 0.01, LFC ≥ 2 or LFC ≤-2). These included miR-4448, miR-338-3p, miR-190a-5p, miR-485-5p, and miR-9-5p. In total, these miRNAs were validated to regulate 55 target genes. Four target genes were found to overlap with the NAD metabolism, sirtuin, and aging pathway, which was thought to control the vascular growth and morphogenesis. The predictive power of our polygenic risk score was apparently high (AUC = 0.909). However, it needs to be interpreted with caution. Conclusion: In this study, we discovered novel DR-specific miRNAs in human serum samples. These circulating miRNAs may represent the pathological changes in the retina in response to diabetes and may serve as non-invasive biomarkers for early DR risk prediction.

4.
Ultramicroscopy ; 204: 10-17, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31112832

RESUMO

In order to address two main obstacles that affect the practical application of coherent modulation imaging (CMI)i.e., the low signal-to-noise ratio (SNR) and limited field of view (FOV), a new algorithm providing extended FOV based on CMI is proposed. A weak scattering modulator was used instead of a binary random phase modulator with strong scattering ability, to improve the final resolution of CMI combined with probe scanning. An unlimited FOV was achieved in a noniterative manner, resulting in a superior SNR compared with ptychography. Compared with the original CMI with a binary random phase modulator, the errors decreased obviously when continuous phase plate was utilized based on simulation and experimental results. Moreover, the random speckles that are associated with coherent diffractive imaging could be effectively eliminated. The proposed algorithm facilitates single-shot or extended FOV phase imaging with a high SNR and high resolution.

5.
Nano Lett ; 19(4): 2450-2455, 2019 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-30915851

RESUMO

Quantitative analysis of the weak antilocalization (WAL) effect of topological surface states in topological insulators is of tremendous importance. The major obstacle to achieve accurate results is how to eliminate the contribution of the anisotropic magnetoconductance of bulk states when the Fermi level lies in bulk bands. Here, we demonstrate that we can analyze quantitatively and accurately the WAL effect of topological surface states in topological insulator, BiSbTeSe2 (BSTS), by measuring the anisotropic magnetoconductance. The anomalous conductance peaks induced by the WAL effect of topological surface states of BSTS together with the anisotropic magnetoconductance of bulk states have been observed. By subtracting the anisotropic magnetoconductance of bulk states, we are able to analyze the WAL effect of topological surface states using the Hikami-Larkin-Nagaoka expression. Our findings offer an alternative strategy for the quantitative exploration of the WAL effect of topological surface states in topological insulators.

6.
Opt Express ; 26(20): 25869-25879, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-30469682

RESUMO

Ptychography is a lensless phase imaging technique that obtains an image by scanning a specimen at several points with respect to a localized illumination beam. For larger specimens, it takes a longer time to complete scanning and hence higher stability is required in the setup which is often not guaranteed. An alternative technique is proposed here that reduces the sequential scanning time for such applications. A pinhole array is used to generate multiple tiny spatially separated beams to scan an object simultaneously at various points. The resulting diffraction patterns are recorded and processed in the Fresnel regime to obtain the images. Unlike other ptychographic methods using multiple beams, the proposed method does not require the use of a multimode ptychography algorithm or autocorrelation filtering of the diffraction patterns. The effectiveness of the method is studied through simulations and experiments. In contrast to conventional single-beam ptychography, the proposed method has the ability to achieve a larger field of view while leaving the number of scanned positions unchanged.

7.
World Neurosurg ; 120: 372-381, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30144612

RESUMO

BACKGROUND: Primary intracranial squamous cell carcinoma (PISCC) is extremely rare, and most cases are caused by malignant changes in an epidermoid cyst or a dermoid cyst. We report a case of intracranial squamous cell carcinoma (SCC) that arose without a preexisting tumor. In addition, the literature on PISCC is reviewed. CASE DESCRIPTION: A 20-year-old man presented with a 4-day history of headache. Magnetic resonance imaging of the brain showed a heterogeneous and irregularly marginated solid-cystic lesion in the left lateral ventricle, which enhanced dramatically. The patient underwent removal of the lesion, and a postoperative histologic examination showed SCC. The patient did not undergo postoperative radiotherapy and was admitted to the hospital again 40 days later because of dizziness, right lower extremity pain, and difficulty in bending. Computed tomography showed hydrocephalus. The cerebrospinal fluid examination confirmed an intracranial infection. The patient was discharged after treatment. The patient survived for 9 months from the onset of the disease. CONCLUSIONS: Most cases of PISCC arise from the malignant transformation of epidermoid cysts. However, SCC arising de novo is even less common. Although rare, the malignant transformation of intracranial epithelial cysts has a poor prognosis. Future prospective trials are necessary to evaluate the optimal treatment modality for patients with PISCC.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Neoplasias do Ventrículo Cerebral/cirurgia , Ventrículos Laterais/cirurgia , Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Neoplasias do Ventrículo Cerebral/diagnóstico por imagem , Neoplasias do Ventrículo Cerebral/patologia , Craniotomia , Humanos , Imuno-Histoquímica , Ventrículos Laterais/diagnóstico por imagem , Ventrículos Laterais/patologia , Imagem por Ressonância Magnética , Masculino , Adulto Jovem
8.
Opt Express ; 26(17): 21929-21938, 2018 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-30130894

RESUMO

A single-shot phase retrieval algorithm based on a random aperture and partially saturated diffraction pattern is proposed. The diffraction pattern in the saturated area could be retrieved during the iterative process, which circumvents the problem of limited dynamic range of the detector. Besides, the random aperture is easier to be manufactured and if the accuracy of the random aperture is high enough, the design value could be used directly for iterations. It has the potential to be adapted for different wavelengths without additional transmission measurement of the wave modulator. The validity has been demonstrated by simulations and experiment.

9.
Appl Opt ; 57(14): 3884-3889, 2018 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-29791358

RESUMO

Because of the limited dynamic range of common detectors, high-frequency components weaker than the threshold of the detector used are lost in digital holography (DH) even with the aid of coherent diffraction imaging (CDI)-based iterative computation, and this makes DH less preferable for many interesting applications. To overcome this problem, the partially saturated diffraction pattern was adopted to enhance the resolution of DH iteratively. Since more high-frequency components were retrieved in comparison with our former CDI-based digital holographic method, the resolution of DH was improved further. The feasibility of the proposed method is demonstrated both numerically and experimentally.

10.
Opt Lett ; 43(8): 1762-1765, 2018 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-29652377

RESUMO

A single shot multi-wavelength phase retrieval method is proposed by combining common coherent modulation imaging (CMI) and a low rank mixed-state algorithm together. A radiation beam consisting of multi-wavelength is illuminated on the sample to be observed, and the exiting field is incident on a random phase plate to form speckle patterns, which is the incoherent superposition of diffraction patterns of each wavelength. The exiting complex amplitude of the sample including both the modulus and phase of each wavelength can be reconstructed simultaneously from the recorded diffraction intensity using a low rank mixed-state algorithm. The feasibility of this proposed method was verified with visible light experimentally. This proposed method not only makes CMI realizable with partially coherent illumination but also can extend its application to various traditionally unrelated fields, where several wavelengths should be considered simultaneously.

11.
Opt Express ; 26(5): 6239-6248, 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-29529815

RESUMO

Coherent modulation imaging (CMI) is a promising technique for online laser beam diagnostics; however, obvious speckle noise is always generated in the reconstruction, seriously degrading the spatial resolution and, accordingly, the accuracy. To solve this problem, both the optical setup of the common CMI and its reconstruction algorithm are slightly modified, and the performance of CMI in laser beam diagnostics can be obviously improved. By adding the second detector to record additional intensity distribution and using it to strengthen the intensity constraint of common CMI algorithm, the speckle noise in the reconstructed image can be distinctively reduced, and thus both the spatial resolution and the measurement accuracy are improved significantly. The feasibility of this proposed method is verified by proof-of-principle experiments.

12.
Nanotechnology ; 29(13): 135705, 2018 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-29432212

RESUMO

We fabricated nanodevices from MoxW1-xTe2 (x = 0, 0.07, 0.35), and conducted a systematic comparative study of their electrical transport. Magnetoresistance measurements show that Mo doping can significantly suppress mobility and magnetoresistance. The results for the analysis of the two band model show that doping with Mo does not break the carrier balance. Through analysis of Shubnikov-de Haas oscillations, we found that Mo doping also has a strong suppressive effect on the quantum oscillation of the sample, and the higher the ratio of Mo, the fewer pockets were observed in our experiments. Furthermore, the effective mass of electron and hole increases gradually with increasing Mo ratio, while the corresponding quantum mobility decreases rapidly.

13.
Nanotechnology ; 2018 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-29337298

RESUMO

We fabricated nanodevices of Mo<sub>x</sub>W<sub>1-x</sub>Te<sub>2</sub> (x =0, 0.07, 0.35) and conducted systematic comparative study of their electrical transport. Magnetoresistance measurements show that Mo doping can significantly suppress the mobility and magnetoresistance. The results for the analysis of two band model (TBM) show that the doping of Mo does not break the carrier balance. By Shubnikov-de Haas oscillations (SdHO) analysis, we found that Mo doping also has a strong suppress on the quantum oscillation of the sample, and the higher the ratio of Mo is, the fewer the pockets observed in our experiments are. Furthermore, with the increase of Mo ratio, the effective mass of electron and hole increases gradually, while the corresponding quantum mobility decreases rapidly.

14.
Sci Rep ; 7(1): 17939, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29247245

RESUMO

A correction to this article has been published and is linked from the HTML version of this paper. The error has not been fixed in the paper.

15.
Sci Rep ; 7(1): 12688, 2017 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-28978938

RESUMO

Here we introduce lattice defects in WTe2 by Ga+ implantation (GI), and study the effects of defects on the transport properties and electronic structures of the samples. Theoretical calculation shows that Te Frenkel defects is the dominant defect type, and Raman characterization results agree with this. Electrical transport measurements show that, after GI, significant changes are observed in magnetoresistance and Hall resistance. The classical two-band model analysis shows that both electron and hole concentration are significantly reduced. According to the calculated results, ion implantation leads to significant changes in the band structure and the Fermi surface of the WTe2. Our results indicate that defect engineering is an effective route of controlling the electronic properties of WTe2 devices.

16.
Nat Commun ; 8(1): 977, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-29042566

RESUMO

Dirac Fermions with different helicities exist on the top and bottom surfaces of topological insulators, offering a rare opportunity to break the degeneracy protected by the no-go theorem. Through the application of Co clusters, quantum Hall plateaus were modulated for the topological insulator BiSbTeSe2, allowing an optimized surface transport. Here, using renormalization group flow diagrams, we show the extraction of two sets of converging points in the conductivity tensor space, revealing that the top surface exhibits an anomalous quantization trajectory, while the bottom surface retains the 1/2 quantization. Co clusters are believed to induce a sizeable Zeeman gap ( > 4.8 meV) through antiferromagnetic exchange coupling, which delays the Landau level hybridization on the top surface for a moderate magnetic field. A quasi-half-integer plateau also appears at -7.2 Tesla. This allows us to study the interesting physics of parity anomaly, and paves the way for further studies simulating exotic particles in condensed matter physics.The topological surface states usually appear in pairs in a topological insulator, with one on the top surface and the other on the bottom surface. Here, Zhang et al. utilize Co cluster to induce a Zeeman gap on one surface through antiferromagnetic exchange coupling, and observe a quasi-half-integer plateau, suggesting the parity anomaly of Dirac fermions.

17.
Sci Rep ; 7(1): 1758, 2017 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-28496170

RESUMO

The recently discovered two-dimensional (2D) semimetal 1 T´-MoTe2 exhibits colossal magnetoresistance and superconductivity, driving a strong research interest in the material's quantum phenomena. Unlike the typical hexagonal structure found in many 2D materials, the 1 T´-MoTe2 lattice has strong in-plane anisotropy. A full understanding of the anisotropy is necessary for the fabrication of future devices which may exploit these quantum and topological properties, yet a detailed study of the material's anisotropy is currently lacking. While angle resolved Raman spectroscopy has been used to study anisotropic 2D materials, such as black phosphorus, there has been no in-depth study of the Raman dependence of 1 T´-MoTe2 on different layer numbers and excitation energies. Here, our angle resolved Raman spectroscopy shows intricate Raman anisotropy dependences of 1 T´-MoTe2 on polarization, flake thickness (from single layer to bulk), photon, and phonon energies. Using a Paczek approximation, the anisotropic Raman response can be captured in a classical framework. Quantum mechanically, first-principle calculations and group theory reveal that the anisotropic electron-photon and electron-phonon interactions are nontrivial in the observed responses. This study is a crucial step to enable potential applications of 1 T´-MoTe2 in novel electronic and optoelectronic devices where the anisotropic properties might be utilized for increased functionality and performance.

18.
Medicine (Baltimore) ; 96(52): e9524, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29384961

RESUMO

RATIONALE: Hemolymphangioma is a rare, noninvasive benign tumor of mesenchymal origin resulting from malformation of vascular and lymphatic vessels. The incidence of hemolymphangioma in the spinal canal is low. PATIENT CONCERNS: This report describes 2 patients with a lesion located in the thoracic spinal canal or spinal epidural space, who were misdiagnosed with suspected meningioma or suspected schwannoma, respectively, based on magnetic resonance imaging (MRI). DIAGNOSES: Hemolymphangioma. INTERVENTIONS: The application of a surgery was designed to treat the 2 patients. OUTCOMES: 2 patients stated that symptoms were improved after the operation. LESSONS: This report should raise awareness among clinicians that careful image analysis and consideration of patient history and pathology is required for accurate differential diagnosis of hemolymphangioma in the spinal canal and spinal epidural space.


Assuntos
Espaço Epidural/patologia , Hemangioma/patologia , Linfangioma/patologia , Canal Vertebral/patologia , Vértebras Torácicas/patologia , Diagnóstico Diferencial , Feminino , Hemangioma/diagnóstico , Hemangioma/cirurgia , Humanos , Linfangioma/diagnóstico , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
19.
Nat Commun ; 7: 13643, 2016 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-27917858

RESUMO

The recent discovery of a Weyl semimetal in TaAs offers the first Weyl fermion observed in nature and dramatically broadens the classification of topological phases. However, in TaAs it has proven challenging to study the rich transport phenomena arising from emergent Weyl fermions. The series MoxW1-xTe2 are inversion-breaking, layered, tunable semimetals already under study as a promising platform for new electronics and recently proposed to host Type II, or strongly Lorentz-violating, Weyl fermions. Here we report the discovery of a Weyl semimetal in MoxW1-xTe2 at x=25%. We use pump-probe angle-resolved photoemission spectroscopy (pump-probe ARPES) to directly observe a topological Fermi arc above the Fermi level, demonstrating a Weyl semimetal. The excellent agreement with calculation suggests that MoxW1-xTe2 is a Type II Weyl semimetal. We also find that certain Weyl points are at the Fermi level, making MoxW1-xTe2 a promising platform for transport and optics experiments on Weyl semimetals.

20.
Sci Rep ; 6: 29254, 2016 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-27404226

RESUMO

Tungsten ditelluride (WTe2) is a semi-metallic layered transition metal dichalcogenide with a stable distorted 1T phase. The reduced symmetry of this system leads to in-plane anisotropy in various materials properties. We have systemically studied the in-plane anisotropy of Raman modes in few-layer and bulk WTe2 by angle-dependent and polarized Raman spectroscopy (ADPRS). Ten Raman modes are clearly resolved. Their intensities show periodic variation with sample rotating. We identify the symmetries of the detected modes by quantitatively analyzing the ADPRS results based on the symmetry selection rules. Material absorption effect on the phonon modes with high vibration frequencies is investigated by considering complex Raman tensor elements. We also provide a rapid and nondestructive method to identify the crystallographic orientation of WTe2. The crystallographic orientation is further confirmed by the quantitative atomic-resolution force image. Finally, we find that the atomic vibrational tendency and complexity of detected modes are also reflected in the shrinkage degree defined based on ADPRS, which is confirmed by corresponding density functional calculation. Our work provides a deep understanding of the interaction between WTe2 and light, which will benefit in future studies about the anisotropic physical properties of WTe2 and other in-plane anisotropic materials.

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