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1.
Nature ; 546(7660): 627-631, 2017 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-28628922

RESUMO

In quantum field theory, Lorentz invariance leads to three types of fermion-Dirac, Weyl and Majorana. Although the existence of Weyl and Majorana fermions as elementary particles in high-energy physics is debated, all three types of fermion have been proposed to exist as low-energy, long-wavelength quasiparticle excitations in condensed-matter systems. The existence of Dirac and Weyl fermions in condensed-matter systems has been confirmed experimentally, and that of Majorana fermions is supported by various experiments. However, in condensed-matter systems, fermions in crystals are constrained by the symmetries of the 230 crystal space groups rather than by Lorentz invariance, giving rise to the possibility of finding other types of fermionic excitation that have no counterparts in high-energy physics. Here we use angle-resolved photoemission spectroscopy to demonstrate the existence of a triply degenerate point in the electronic structure of crystalline molybdenum phosphide. Quasiparticle excitations near a triply degenerate point are three-component fermions, beyond the conventional Dirac-Weyl-Majorana classification, which attributes Dirac and Weyl fermions to four- and two-fold degenerate points, respectively. We also observe pairs of Weyl points in the bulk electronic structure of the crystal that coexist with the three-component fermions. This material thus represents a platform for studying the interplay between different types of fermions. Our experimental discovery opens up a way of exploring the new physics of unconventional fermions in condensed-matter systems.

2.
Zhonghua Yi Xue Za Zhi ; 103(38): 3033-3040, 2023 Oct 17.
Artigo em Zh | MEDLINE | ID: mdl-37813654

RESUMO

Objective: To explore the difference of peripheral blood mononuclear cells (PBMC) transcripts between atopic dermatitis (AD) and healthy controls, and to screen and preliminarily validate potential biomarkers of AD. Methods: From January 2021 to May 2022, blood samples from 9 AD patients and 10 healthy controls were collected from the Dermatology and Cosmetic Center of the Third Affiliated Hospital of Chongqing Medical University, ribonucleic acid-sequencing (RNA-seq) was used to determine the transcriptome and relative expression of PBMC, the differentially expressed genes (DEGs) were analyzed by gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction networks (PPI) analysis, and the potential biomarkers were identified by quantitative real-time PCR (qRT-PCR). Results: The age of patients in the AD group [M (Q1, Q3)] was 26.50 (22.75, 30.50) years old, and the course of disease [M (Q1, Q3)] was 15 (10, 20) years,and the age of the healthy control group [M (Q1, Q3)] was 37.00 (27.75, 40.25) years old. Compared with healthy controls, 1 044 DEGs were detected in PBMC samples in AD group, including 668 up-regulated genes and 376 down-regulated genes. Differential variable splicing (AS) showed that mutually exclusive exons (46.74%) and skipped exon (31.01%) accounted for a large proportion. GO and KEGG enrichment analysis revealed that AD is closely linked to DEGs implicated in the inflammatory response and cytokine interaction and signal pathway. Comprehensive enrichment analysis and PPI analysis selected the expression of 8 candidate genes (CCL4, CCR3, CXCR5, NFKBIA, CXCL1, IL-1B, CCL20, LY96), which was confirmed by qRT-PCR and were consistent with that of RNA-seq. Conclusions: CCL4, CCR3, CXCR5, NFKBIA, CXCL1, IL-1B, CCL20 and LY96 might be potential biomarkers of AD, participating in the occurrence and development of AD.


Assuntos
Dermatite Atópica , Perfilação da Expressão Gênica , Humanos , Adulto , Leucócitos Mononucleares , Biomarcadores , Transcriptoma , RNA , Biologia Computacional
3.
Biophys J ; 121(12): 2290-2296, 2022 06 21.
Artigo em Inglês | MEDLINE | ID: mdl-35614854

RESUMO

The matrix proteins (M) of many enveloped RNA viruses mediate virus assembly and budding. However, it remains poorly understood how M are involved in virus budding and how they interact with envelope proteins. Here, we show that the expression level of Nipah (NiV) M in particles produced by the host cells deviates from a gamma distribution and does not reflect that of the host cells, indicating assembly of the NiV-M in the process. Our data reveal that NiV-M affects the circularity of the particles while the NiV envelope proteins do not. The organization of NiV envelope proteins on the membrane of the particles is similar to those that do not express NiV-M, suggesting that NiV-M does not directly interact with the envelope proteins during assembly and budding.


Assuntos
Vírus Nipah , Microscopia , Vírus Nipah/genética , Proteínas do Envelope Viral/metabolismo , Proteínas da Matriz Viral/metabolismo , Vírion/metabolismo , Montagem de Vírus
4.
Clin Radiol ; 76(1): 81.e11-81.e19, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32962807

RESUMO

AIM: To evaluate the imaging characteristics of simultaneous multi-slice (SMS) accelerated diffusion-weighted imaging (DWI) with decreased section thickness, with and without motion correction, in comparison to conventional DWI (cDWI) for the detection of lesions in patients with neuroendocrine tumour (NET) liver metastases. MATERIALS AND METHODS: Fifteen patients with NET liver metastases underwent cDWI (section thickness [SL]=4 mm) and SMS-DWI (SL=2 mm). Non-linear motion-corrected (Moco)-SMS-DWI was generated in addition to the original series. Qualitative imaging characteristics (five-point Likert scale), the number of high signal lesions, and the detectability and delineation of lesions were evaluated and compared using the Friedman and the Dunn-Bonferroni tests. The test-retest variability (TRV) of the cDWI and SMS-DWI techniques was investigated among 11 healthy volunteers who underwent cDWI (SL=4 mm) and SMS-DWI (SL=4 mm) twice. The Friedman and the Dunn-Bonferroni post-hoc tests were used to compare the mean apparent diffusion coefficient (ADC) and the TRV in different liver regions between the three series. RESULTS: Moco-SMS-DWI demonstrated significantly superior overall image quality (p<0.001) with significantly fewer artefacts (p=0.003) than cDWI. The number of lesions detected by cDWI, SMS-DWI, and Moco-SMS-DWI were 348, 504, and 523, respectively. The detectability and delineation of the lesions and the ADC values were significantly higher on the SMS-DWI and Moco-SMS-DWI images than on the cDWI images (all p<0.001). Moco-SMS-DWI showed significantly higher TRV than cDWI in regions near the liver edge (p=0.018). CONCLUSIONS: SMS-DWI achieves higher spatial resolution than cDWI within the same acquisition time, detects more lesions, and provides better lesion delineation. By applying motion correction, the TRV of DWI could be enhanced in regions near the liver edge.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/secundário , Tumores Neuroendócrinos/patologia , Adulto , Idoso , Estudos de Casos e Controles , Meios de Contraste , Ácido Edético , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Compostos Organometálicos , Estudos Prospectivos , Reprodutibilidade dos Testes
5.
Zhonghua Yi Xue Za Zhi ; 101(13): 934-938, 2021 Apr 06.
Artigo em Zh | MEDLINE | ID: mdl-33789374

RESUMO

Objective: To explore the prognosis effect of the expression of long-chain non-coding RNA (lncRNA) MBNL1-AS1 on acute myeloid leukemia (AML) patients. Methods: One hundred and twenty-five AML patients of the Cancer Genome Atlas (TCGA) from November 2001 to March 2010 were involved, including 70 patients who received chemotherapy only and other 55 patients treated with allogeneic hematopoietic stem cell transplantation (allo-HSCT) in addition to chemotherapy. According to the median expression of lncRNA MBNL1-AS1, patients of chemotherapy group were divided into high expression sub-group(n=35) and low expression sub-group (n=35), and patients of allo-HSCT group were also divided into high expression sub-group (n=28) and low expression sub-group (n=27) for prognosis analysis. Clinical characteristics at diagnosis, including peripheral white blood cell counts (WBC), blast percentages in peripheral blood and bone marrow (BM), French-American-British (FAB) subtypes and the frequencies of common genetic mutations in AML were described. The event-free survival (EFS) rate and overall survival (OS) rate of patients in different groups were analyzed, and the influence of the clinical characteristics of patients on the prognosis of AML was analyzed by COX multivariate analysis. Results: In the chemotherapy group, patients with low lncRNA-MBNL1-AS1 expression had significantly lower EFS and OS (60.0%, 8.6%) than patients with high lncRNA-MBNL1-AS1 expression (68.6%, 34.3%) (χ²=7.817, 10.880, all P<0.01). However, in the alloHSCT group, no significant differences were observed in EFS and OS of patients between high and low expression groups of lncRNA-MBNL1-AS1 (all P>0.05). COX multivariate analysis confirmed that age≥60 years old (EFS: HR (95%CI): 6.934 (1.918-25.075),P=0.003;OS: HR (95%CI): 4.119 (1.812-9.364), P=0.001), and low expression of lncRNA MBNL1-AS1 (EFS: HR (95%CI): 0.354 (0.126-0.941), P=0.038; OS: HR (95%CI): 0.424 (0.231-0.778), P=0.006)were independent risk factors for EFS and OS in the chemotherapy group. Conclusion: The long-chain non-coding RNA MBNL1-AS1 is related to the prognosis of AML, and its low expression is an independent poor prognostic factor in AML patients.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , RNA Longo não Codificante , Humanos , Leucemia Mieloide Aguda/genética , Pessoa de Meia-Idade , Prognóstico , Intervalo Livre de Progressão , RNA Longo não Codificante/genética , Proteínas de Ligação a RNA
6.
Zhonghua Yi Xue Za Zhi ; 100(8): 610-613, 2020 Mar 03.
Artigo em Zh | MEDLINE | ID: mdl-32164116

RESUMO

Objective: To investigate the causes of misdiagnosis of suprasellar arachnoid cysts, analyze its characteristics and put forward the diagnostic basis and differential points. Methods: The clinical data fo 97 cases of suprasellar arachnoid cysts diagnosed and treated in the neurosurgery department of Beijing Tiantan Hospital and Hebei General Hospital from March 2015 to March 2019 were analyzed retrospectively. All patients underwent CT and MRI scans with obstructive hydrocephalus. 13 cases were misdiagnosed, including 7 males and 6 females. First visit age 1-31 years old, with an average age of 6.3 years. There were 10 patients younger than 6 years old. The remaining 15-year-old patients, 31-year-old patients and 26-year-old patients each have one case. 11 cases were misdiagnosed as obstructive hydrocephalus, 2 cases as cystic craniopharyngioma. Results: 13 cases were misdiagnosed and mistreated, 11 cases were treated with intraventricular and abdominal shunt, 9 cases were treated with neuroendoscopy and recovered well. One cases of intracranial hematomas underwent craniotomy again, the hematomas were removed again and the bone slise were decompressed. One case had fissured stable after shunt. There were no operative deaths and no complications in this group. After endoscopic reoperation, CT and/or MRI scans showed that the ventricle narrowed in varying degrees, some of them returned to normal size and the flow of cerebrospinal fluid (cerebrospinal fluid) was unobstruct at the end of magnetic resonance cerebrospinal fluid angiography (MRI) fistula after endoscopic reoperation. Conclusions: The incidence of suprasellar arachnoid cysts is low, it is rare in clinic and it is easy to misdiagnose and mistreate. At present, it is recognized that the best treatment methods are partial resection of endoscope cyst wall, cyst ventricle fistula and third ventricle floor fisthla.


Assuntos
Cistos Aracnóideos , Neuroendoscopia , Neoplasias Hipofisárias , Adolescente , Adulto , Criança , Pré-Escolar , Erros de Diagnóstico , Feminino , Humanos , Lactente , Imageamento por Ressonância Magnética , Masculino , Estudos Retrospectivos , Adulto Jovem
7.
Neuroimage ; 192: 52-65, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30669009

RESUMO

How pain emerges from cortical activities remains an unresolved question in pain neuroscience. A first step toward addressing this question consists in identifying brain activities that occur preferentially in response to painful stimuli in comparison to non-painful stimuli. A key confound that has affected this important comparison in many previous studies is the intensity of the stimuli generating painful and non-painful sensations. Here, we compared the brain activity during iso-intense painful and tactile sensations sampled by functional MRI in 51 healthy participants. Specifically, the perceived intensity was recorded for every stimulus and only the stimuli with rigorously matched perceived intensity were selected and compared between painful and tactile conditions. We found that all brain areas activated by painful stimuli were also activated by tactile stimuli, and vice versa. Neural responses in these areas were correlated with the perceived stimulus intensity, regardless of stimulus modality. More importantly, among these activated areas, we further identified a number of brain regions showing stronger responses to painful stimuli than to tactile stimuli when perceived intensity was carefully matched, including the bilateral opercular cortex, the left supplementary motor area and the right frontal middle and inferior areas. Among these areas, the right frontal middle area still responded more strongly to painful stimuli even when painful stimuli were perceived less intense than tactile stimuli, whereas in this condition other regions showed stronger responses to tactile stimuli. In contrast, the left postcentral gyrus, the visual cortex, the right parietal inferior gyrus, the left parietal superior gyrus and the right cerebellum had stronger responses to tactile stimuli than to painful stimuli when perceived intensity was matched. When tactile stimuli were perceived less intense than painful stimuli, the left postcentral gyrus and the right parietal inferior gyrus still responded more strongly to tactile stimuli while other regions now showed similar responses to painful and tactile stimuli. These results suggest that different brain areas may be engaged differentially when processing painful and tactile information, although their neural activities are not exclusively dedicated to encoding information of only one modality but are strongly determined by perceived stimulus intensity regardless of stimulus modality.


Assuntos
Encéfalo/fisiologia , Percepção da Dor/fisiologia , Percepção do Tato/fisiologia , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Física/métodos , Adulto Jovem
8.
Clin Radiol ; 74(4): 325.e1-325.e8, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30638606

RESUMO

AIM: To compare the simultaneous multi-slice (SMS) and integrated slice-by-slice shimming (iShim) single-shot echo planar imaging (ssEPI) for diffusion-weighted imaging (DWI) of the kidneys. MATERIALS AND METHODS: In this prospective study, six healthy volunteers and 22 patients with renal diseases underwent SMS and iShim DWI of the kidney with five b-values (0, 80, 400, 800, 1,600 s/mm2) at 3 T. The subjective image quality, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and ADC values were evaluated. The subjective image quality scores, SNR, CNR, ADC values and scan time of SMS and iShim DWI were compared. RESULTS: Scan time of SMS DWI (1 minute 38 seconds) was significantly reduced compared to iShim ssEPI (3 minutes 33 seconds). No statistically significant differences in the SNR or subjective image quality were observed on the b=0 images, but the SNR and overall image quality scores were significantly higher on the other four b-value images at SMS DWI. Image distortions were also comparable, but there were fewer artefacts on the b=80 and b=800 images in SMS DWI. CNR was significantly higher on the b=0 and b=1,600 images in SMS DWI. SNR and subjective image-quality scores of ADC maps were significantly higher in SMS DWI, whereas CNR showed no significant difference. The ADC value of renal parenchyma was similar in SMS and iShim DWI (1.54±0.11 × 10-3 versus 1.52±0.16×10-3 mm2/s, p=0.343). CONCLUSION: SMS can substantially reduce imaging time of kidney DWI with slightly improved image quality and comparable ADC values of renal parenchyma compared to iShim ss-EPI sequence.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Interpretação de Imagem Assistida por Computador/métodos , Nefropatias/diagnóstico por imagem , Adulto , Feminino , Humanos , Rim/diagnóstico por imagem , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes , Razão Sinal-Ruído
9.
Clin Radiol ; 74(1): 81.e19-81.e24, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30389175

RESUMO

AIM: To investigate whether there is an optimal time in the menstrual cycle to obtain the best image quality of uterine zonal structures with high-field magnetic resonance imaging (MRI). MATERIALS AND METHODS: Thirty-eight normal volunteers with regular menstrual cycles underwent pelvic 3 T high-resolution T2-weighted three-dimensional (3D) turbo spin echo (TSE) with variable flip angle MRI examinations during the menstrual phase (MP), follicular phase (FP), peri-ovulatory phase (OP), and luteal phase (LP). Two radiologists blinded evaluated the boundary sharpness of the three zonal structures of the uterine corpus and cervix on mid-sagittal images using a three-point Likert-scale. The signal intensity (SI) on T2-weighted sequences of each zonal structure was measured and the ratio between the SI of adjacent structures was calculated. Paired Wilcoxon's test and repeated measurement analysis of variance were used to investigate the differences among the four phases. RESULTS: No variation during the menstrual cycle was found in 10.5% (4/38) of volunteers and their boundaries were all well-defined. The OP exhibited the clearest boundaries of the corpus zonal structures. For the endometrium to junctional zone, mean scores of boundary sharpness from high to low were 3 (OP), 2.97 (FP), 2.76 (LP), 2.74 (MP); that for the junctional zone to myometrium were 2.76 (OP), 2.42 (FP), 2.32 (LP), 2.11 (MP); which were consistent with the SI ratio results. The results for the cervix showed no statistical difference during the menstrual cycle (p>0.05), and was well-defined throughout. CONCLUSIONS: The OP is recommended as the best phase to investigate zonal-related uterine corpus diseases due to the best contrast. For cervical diseases, imaging could be performed when necessary at any time point, due to the limited influence of menstrual phases on cervical zone delineation.


Assuntos
Imageamento por Ressonância Magnética/métodos , Ciclo Menstrual , Útero/diagnóstico por imagem , Adulto , Colo do Útero/diagnóstico por imagem , Colo do Útero/fisiologia , Endométrio/diagnóstico por imagem , Endométrio/fisiologia , Feminino , Humanos , Aumento da Imagem , Ovulação , Útero/fisiologia , Adulto Jovem
10.
Nano Lett ; 17(3): 1616-1622, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28145719

RESUMO

MoTe2 is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T'- or ß-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ∼1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe2 through W substitution by unveiling the phase-diagram of the Mo1-xWxTe2 solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration xc ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with x close to xc might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe2.

11.
Phys Rev Lett ; 118(4): 046802, 2017 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-28186797

RESUMO

We discover a pair of spin-polarized surface bands on the (111) face of grey arsenic by using angle-resolved photoemission spectroscopy (ARPES). In the occupied side, the pair resembles typical nearly-free-electron Shockley states observed on noble-metal surfaces. However, pump-probe ARPES reveals that the spin-polarized pair traverses the bulk band gap and that the crossing of the pair at Γ[over ¯] is topologically unavoidable. First-principles calculations well reproduce the bands and their nontrivial topology; the calculations also support that the surface states are of Shockley type because they arise from a band inversion caused by crystal field. The results provide compelling evidence that topological Shockley states are realized on As(111).

12.
Phys Rev Lett ; 118(10): 106406, 2017 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-28339253

RESUMO

The Weyl semimetal phase is a recently discovered topological quantum state of matter characterized by the presence of topologically protected degeneracies near the Fermi level. These degeneracies are the source of exotic phenomena, including the realization of chiral Weyl fermions as quasiparticles in the bulk and the formation of Fermi arc states on the surfaces. Here, we demonstrate that these two key signatures show distinct evolutions with the bulk band topology by performing angle-resolved photoemission spectroscopy, supported by first-principles calculations, on transition-metal monophosphides. While Weyl fermion quasiparticles exist only when the chemical potential is located between two saddle points of the Weyl cone features, the Fermi arc states extend in a larger energy scale and are robust across the bulk Lifshitz transitions associated with the recombination of two nontrivial Fermi surfaces enclosing one Weyl point into a single trivial Fermi surface enclosing two Weyl points of opposite chirality. Therefore, in some systems (e.g., NbP), topological Fermi arc states are preserved even if Weyl fermion quasiparticles are absent in the bulk. Our findings not only provide insight into the relationship between the exotic physical phenomena and the intrinsic bulk band topology in Weyl semimetals, but also resolve the apparent puzzle of the different magnetotransport properties observed in TaAs, TaP, and NbP, where the Fermi arc states are similar.

13.
J Clin Pharm Ther ; 42(5): 519-529, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28639290

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Therapeutic effects of anti-VEGF agents, corticosteroids and laser therapy have been previously examined for treating macular oedema secondary to branch and central retinal vein occlusion (BRVO and CRVO). However, anti-VEGF efficacy has not been previously compared to corticosteroid or laser therapy efficacy. We performed a meta-analysis to compare these treatments. METHODS: Pertinent publications were identified through comprehensive literature searches. Therapeutic effects were estimated using best-corrected visual acuity (BCVA), central retinal thickness (CRT) and intraocular pressure (IOP). The Review Manager (version 5.3.5) was used to perform searches. RESULTS AND DISCUSSION: Eleven randomized, controlled trials that included 1045 RVO patients were identified. For eyes with BRVO, anti-VEGF therapy improved BCVA significantly more than corticosteroid/laser therapy at 3 (P=.0002), 6 (P<.00001) and 12 months (P<.00001). For eyes with CRVO, this difference was only significant at 6 months (P=.002). The same was true when efficacy was examined using CRT at 3 and 6 months (BRVO: both P<.00001, CRVO 6 months: P=.02). Long-term efficacy of anti-VEGF agents was limited in eyes with BRVO and CRVO. Improvements in BCVA were similar at 1 and 3 months (P=.74), but BCVA decreased between 3 and 6 months (P=.03). In contrast, BCVA progressively decreased 1 and 6 months following corticosteroid/laser therapy (both P<.00001). Lastly, eyes that had been treated with anti-VEGF agents had significantly lower IOP changes than eyes treated with corticosteroids/laser 3 and 6 months after initiating therapy (both P<.00001). WHAT IS NEW AND CONCLUSION: Anti-VEGF agents improve BCVA and reduce CRT more effectively and longer than corticosteroid/laser in eyes with RVO. Anti-VEGF agents also have a lower risk of elevating IOP. Additionally, anti-VEGF agents are more effective for treating BRVO than CRVO.


Assuntos
Edema Macular/terapia , Oclusão da Veia Retiniana/complicações , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Inibidores da Angiogênese/uso terapêutico , Glucocorticoides/uso terapêutico , Humanos , Terapia a Laser/métodos , Edema Macular/etiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Oclusão da Veia Retiniana/terapia , Acuidade Visual
14.
Zhonghua Yan Ke Za Zhi ; 53(2): 148-153, 2017 Feb 11.
Artigo em Zh | MEDLINE | ID: mdl-28260368

RESUMO

Retinitis pigmentosa (RP) is a genetically heterogeneous group of hereditary retinal disorders characterized by photoreceptor cell death, associated with night blindness, vision loss, progressive peripheral visual field loss and abnormalities in the electroretinogram. A number of gene defects have so far been associated with RP, which cause a progressive loss of rod photoreceptor function, followed by cone photoreceptor dysfunction and eventually complete blindness. The rate of blindness related to RP is high. At present there is no effective therapeutic strategy for RP. In recent years, with the progress of molecular biology technique, many new therapeutic approaches have become promising. This article summarizes the pathogenesis of RP and gives a brief overview of related research progress of RP therapeutic strategies. (Chin J Ophthalmol, 2017, 53: 148-153).


Assuntos
Retinose Pigmentar/terapia , Cegueira/etiologia , Distrofias de Cones e Bastonetes/etiologia , Eletrorretinografia , Humanos , Relatório de Pesquisa , Células Fotorreceptoras Retinianas Cones , Células Fotorreceptoras Retinianas Bastonetes , Retinose Pigmentar/etiologia
15.
Phys Rev Lett ; 117(12): 127204, 2016 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-27689296

RESUMO

By combining angle-resolved photoemission spectroscopy and quantum oscillation measurements, we performed a comprehensive investigation on the electronic structure of LaSb, which exhibits near-quadratic extremely large magnetoresistance (XMR) without any sign of saturation at magnetic fields as high as 40 T. We clearly resolve one spherical and one intersecting-ellipsoidal hole Fermi surfaces (FSs) at the Brillouin zone (BZ) center Γ and one ellipsoidal electron FS at the BZ boundary X. The hole and electron carriers calculated from the enclosed FS volumes are perfectly compensated, and the carrier compensation is unaffected by temperature. We further reveal that LaSb is topologically trivial but shares many similarities with the Weyl semimetal TaAs family in the bulk electronic structure. Based on these results, we have examined the mechanisms that have been proposed so far to explain the near-quadratic XMR in semimetals.

16.
Zhonghua Yi Xue Za Zhi ; 96(1): 48-52, 2016 Jan 05.
Artigo em Zh | MEDLINE | ID: mdl-26792608

RESUMO

OBJECTIVE: To investigate the incidence and influencing factors of term small for gestational age infants (SGA ) in China. METHODS: This study is a multicenter study. Data were collected from Chinese Neonatal Network with term infants, born from May 1st 2010 to February 28th 2014, from 83 nationwide hospitals. RESULTS: A total of 170 565 neonates were recorded from 83 nationwide hospitals; 144 659 cases were term newborn, and 3 543 neonates were found to be term SGA. The incidence of term SGA was 2.45%. In term SGA, the girl's incidence (2.88%, 1 985/69 003) was higher than boy (2.05%, 1 531/74 707), P<0.001. Furthermore, the incidence of in vitro fertilization (IVF) and artificial fertilization of term SGA was 9.12% (66/724), which was higher than the natural conception (2.42%, 3 465/143 283), P<0.001. The incidence of term SGA in multiple births (30.37%, 741/2 440) was higher than that of single birth (1.97%, 2 787/141 366), P<0.001. The incidence of SGA with maternal age <18 years old was 4.86% (27/556) and was 3.20% (307/9 592) with maternal age > 35 years old, meanwhile both were higher than that with maternal age as 18-35 years old (2.39%, 3 197/133 662). The incidence of SGA with maternal occupation as farmers was 4.67% (854/18 284), which was significantly higher than other professions. The incidence of SGA with maternal education as illiterate and elementary education was 8.65% (187/2 162), 5.17% (397/7 678), respectively, both were significantly higher than those with mother graduated from university (1.72%, 853/49 692). Moreover, the geographical distribution of the main residence of the term SGA mothers showed Northeast Area (1.54%, 30/1 946)and East Area (2.21%, 1 267/57 334) had lower incidence of term SGA than those of Central South Area (2.71%, 493/18 223) and Southwest Area (3.67%, 876/23 852). CONCLUSIONS: The incidence of term SGA was 2.45% in this study, which was influenced significantly by gender, IVF, multiple births, maternal factors (age, maternal occupation, level of education) and geographical distribution. This multicenter study with large data, to a certain extent, reflected status of the incidence and influencing factors of term SGA in China, which will help prevent and treat term SGA.


Assuntos
Idade Gestacional , Recém-Nascido Pequeno para a Idade Gestacional , Adolescente , Adulto , China , Feminino , Fertilização in vitro , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Idade Materna , Mães , Adulto Jovem
17.
Zhonghua Yi Xue Za Zhi ; 96(22): 1766-72, 2016 Jun 14.
Artigo em Zh | MEDLINE | ID: mdl-27356646

RESUMO

OBJECTIVE: To investigate the characteristics and outcomes of necrotizing enterocolitis (NEC) in Chinese term infants population. METHODS: A national neonatal necrotizing enterocolitis network was established. Neonates as having necrotizing enterocolitis with gestation age ≥37 weeks were identified if they met the accepted diagnostic criterion during the study period from Jan 1(st) 2011 to Dec 31(st) 2011. The data of maternal and neonates' characteristics, the comorbidities, the clinical interventions prior to NEC, the clinical courses and radiology results, the medical and surgical treatment and the outcomes were collected. SPSS 19.0 software was used to do statistic analysis. Logistic-regression models were used to analyze the risk factors for death in infants with NEC, odds ratio (OR) and 95% confidence interval (CI) were calculated. RESULTS: There were 231 067 newborn infants, 164 307 of them were term infants, admitted to 95 hospitals in main land China. There were 718 term infants were diagnosed as necrotizing enterocolitis with the incidence of 0.44%. There were 294 term infants cases identified as ≥stage 2 necrotizing enterocolitis for the analysis, including 193 cases of stage 2 and 101 cases of stage 3.The mean gestation age was (39.0±1.3) weeks, and the mean birth weight was(3 087.4±548.3)g. The percentage of small for gestation age was 20.4%. The onset age of NEC was 5 (2-11)d. The percentage of cases received breast milk feeding was 23.7%. The most common comorbidities were sepsis (9.5%, 28/294), asphyxia (9.5%, 28/294), pneumonia (7.8%, 23/294) and congenital megacolon (7.5%, 22/294). The bowel perforation rate was 13.9%. The rate of cases who received surgical treatment was 25.2%(76.6% small intestinal necrosis and 65.8% small intestinal perforation). The mortality rate was 28.9%(the mortality rate were 20.7% and 44.6% in stage 2 and stage 3 NEC, respectively). Noninvasive continuous positive airway pressure treatment for NEC (OR=5.278, 95% CI: 2.058-13.533, P<0.01) and NEC staging 3 (OR=3.156, 95% CI: 1.766-5.642, P<0.01) were statistically significantly associated with mortality of NEC. CONCLUSIONS: The term infants with necrotizing enterocolitis usually have the underlying comorbidities. The breastmilk feeding rate is low. Necrotizing enterocolitis remains high mortality in term neonates in Chinese neonatal units. Noninvasive continuous positive airway pressure treatment for NEC is statistically significantly associated with mortality of NEC.


Assuntos
Peso ao Nascer , Enterocolite Necrosante/epidemiologia , Asfixia/epidemiologia , China/epidemiologia , Comorbidade , Enterocolite Necrosante/complicações , Enterocolite Necrosante/cirurgia , Feminino , Idade Gestacional , Humanos , Incidência , Lactente , Recém-Nascido , Recém-Nascido de muito Baixo Peso , Perfuração Intestinal/epidemiologia , Modelos Logísticos , Razão de Chances , Fatores de Risco , Sepse/epidemiologia , Resultado do Tratamento
18.
Phys Rev Lett ; 115(21): 217601, 2015 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-26636872

RESUMO

We have investigated the spin texture of surface Fermi arcs in the recently discovered Weyl semimetal TaAs using spin- and angle-resolved photoemission spectroscopy. The experimental results demonstrate that the Fermi arcs are spin polarized. The measured spin texture fulfills the requirement of mirror and time-reversal symmetries and is well reproduced by our first-principles calculations, which gives strong evidence for the topologically nontrivial Weyl semimetal state in TaAs. The consistency between the experimental and calculated results further confirms the distribution of chirality of the Weyl nodes determined by first-principles calculations.

19.
Phys Rev Lett ; 113(26): 266407, 2014 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-25615365

RESUMO

The electronic structure of the iron-based superconductor Ba2Ti2Fe2As4O (Tc(onset)=23.5 K) has been investigated by using angle-resolved photoemission spectroscopy and combined local density approximation and dynamical mean field theory calculations. The electronic states near the Fermi level are dominated by both the Fe 3d and Ti 3d orbitals, indicating that the spacer layers separating different FeAs layers are also metallic. By counting the enclosed volumes of the Fermi surface sheets, we observe a large self-doping effect; i.e., 0.25 electrons per unit cell are transferred from the FeAs layer to the Ti2As2O layer, leaving the FeAs layer in a hole-doped state. This exotic behavior is successfully reproduced by our dynamical mean field calculations, in which the self-doping effect is attributed to the electronic correlations in the 3d shells. Our work provides an alternative route of effective doping without element substitution for iron-based superconductors.

20.
Genet Mol Res ; 13(1): 1402-11, 2014 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-24634239

RESUMO

Duchenne muscular dystrophy (DMD) is the most common form of muscular dystrophy with no cure currently available. In this study, using two microarray data sets obtained from the Gene Expression Omnibus database, we conducted a dysfunctional pathway-enrichment analysis and investigated deregulated genes that are specific to different phases of the disease in order to determine pathogenic characteristics in the progression of DMD. We identified 41 and 33 dysfunctional pathways that were enriched with differentially expressed genes in presymptomatic patients and in symptomatic patients, respectively. Over 70% of pathways were shared between both phases and many of them involved the inflammatory process, suggesting that inflammatory cascades were induced soon after the birth of the patients. Further investigation showed that presymptomatic patients performed better with respect to muscle regeneration and cardiac muscle calcium homeostasis maintenance. Neuronal nitric oxide synthase, dihydropyridine receptors, sarcoplasmic/endoplasmic reticulum calcium ATPase, and phospholamban may serve as potential targets for further molecular diagnostic tests. Our results may provide a better understanding for the treatment of DMD.


Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Distrofia Muscular de Duchenne/genética , Transcriptoma , Biologia Computacional/métodos , Bases de Dados de Ácidos Nucleicos , Progressão da Doença , Redes Reguladoras de Genes , Humanos , Redes e Vias Metabólicas , Distrofia Muscular de Duchenne/metabolismo , Transdução de Sinais
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