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1.
Curr Med Sci ; 41(5): 966-973, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34652628

RESUMO

OBJECTIVE: To comprehensively and accurately analyze the out-performance of low-dose chest CT (LDCT) vs. standard-dose CT (SDCT). METHODS: The image quality, size measurements and radiation exposure for LDCT and SDCT protocols were evaluated. A total of 117 patients with extra-thoracic malignancies were prospectively enrolled for non-enhanced CT scanning using LDCT and SDCT protocols. Three experienced radiologists evaluated subjective image quality independently using a 5-point score system. Nodule detection efficiency was compared between LDCT and SDCT based on nodule characteristics (size and volume). Radiation metrics and organ doses were analyzed using Radimetrics. RESULTS: The images acquired with the LDCT protocol yielded comparable quality to those acquired with the SDCT protocol. The sensitivity of LDCT for the detection of pulmonary nodules (n=650) was lower than that of SDCT (n=660). There was no significant difference in the diameter and volume of pulmonary nodules between LDCT and SDCT (for BMI <22 kg/m2, 4.37 vs. 4.46 mm, and 43.66 vs. 46.36 mm3; for BMI ≥22 kg/m2, 4.3 vs. 4.41 mm, and 41.66 vs. 44.86 mm3) (P>0.05). The individualized volume CT dose index (CTDIvol), the size specific dose estimate and effective dose were significantly reduced in the LDCT group compared with the SDCT group (all P<0.0001). This was especially true for dose-sensitive organs such as the lung (for BMI <22 kg/m2, 2.62 vs. 12.54 mSV, and for BMI ≥22 kg/m2, 1.62 vs. 9.79 mSV) and the breast (for BMI <22 kg/m2, 2.52 vs. 10.93 mSV, and for BMI ≥22 kg/m2, 1.53 vs. 9.01 mSV) (P<0.0001). CONCLUSION: These results suggest that with the increases in image noise, LDCT and SDCT exhibited a comparable image quality and sensitivity. The LDCT protocol for chest scans may reduce radiation exposure by about 80% compared to the SDCT protocol.

2.
Sci Total Environ ; 804: 149965, 2021 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-34508937

RESUMO

Ammonium removal in wastewater treatment plants demands large quantities energy input, such as aeration for wastewater and the addition of organics for nitrate reduction. Anaerobic ammonium oxidation coupled to Fe(III) reduction, called Feammox process play a crucial role in natural nitrogen cycle, which has been rarely investigated in the field of wastewater treatment. Besides, Iron-reducing bacteria (FeRB) as function bacteria of Feammox could transfer electrons to iron oxide by oxidizing organics. The possibility of anaerobic ammonium removal coupled with organics should be investigated to assess the potential of Feammox process for conventional wastewater treatment. In this study, five Fe(III) compounds, Fe2O3, Fe3O4, Fe(OH)3, Citrate-Fe and pyrite were supplemented to investigate the effect of iron oxides on ammonium removal in serum bottles with working volume of 100 mL. It was found that ammonium removal efficiency of the Fe2O3 group was the highest. To simulate wastewater treatment process in sewage treatment plant, three Up-flow anaerobic sludge blanket reactors with volume of 250 mL adding Fe2O3 were applied with influent of ammonium and carbon sources. It was found that the organics significantly inhibited the ammonium removal by Feammox process. This was attributed to that carbon sources and ammonium could be used as electron donors for Fe(III) reduction. In addition, this nitrogen removal was also likely related with the iron cycle, i.e., Fe(III) reduction with ammonium oxidation and Fe(II) oxidation with nitrate/nitrite reduction. This study provides a promising alternative technology for anaerobic ammonium removal in wastewater treatment. Optimizing nitrogen removal and carbon sources applied in conventional wastewater plants are required in future.

3.
Artigo em Inglês | MEDLINE | ID: mdl-34304355

RESUMO

Non-point source (NPS) pollution has become a vital contaminant source affecting the water environment because of its wide distribution, hydrodynamic complexity, and difficulty in prevention and control. In this study, the identification and evaluation of NPS pollution risk based on landscape pattern were carried out in the Hanjiang River basin above Ankang hydrological section, Shaanxi province, China. Landscape distribution information was obtained through land use data, analyzing the contribution of "source-sink" landscape to NPS pollution through the location-weighted landscape contrast index. Using the NPS pollution risk index to identify and evaluate the regional NPS pollution risk considering the slope, cost distance, soil erosion, and precipitation erosion affect migration of pollutants. The results showed that (i) the pollution risk was generally high in the whole watershed, and the sub-watersheds dominated by "source" landscapes account for 74.61% of the whole basin; (ii) the high-risk areas were distributed in the central, eastern, and western regions of the river basin; the extremely high-risk areas accounted for 12.7% of the whole watershed; and the southern and northern regions were dominated by forestland and grassland with little pollution risk; (iii) "source" landscapes were mostly distributed in areas close to the river course, which had a great impact on environment, and the landscape pattern units near the water body needed to be further adjusted to reduce the influence of NPS pollution.

4.
PLoS One ; 16(7): e0254000, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34214117

RESUMO

Colorectal cancer (CRC) is the third most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in the world. It has been the most prevalent malignancy in Taiwan for consecutive thirteen years. Despite the diversity of its etiologic and pathophysiologic factors, a biological process named as epithelial-mesenchymal transition (EMT) is indispensable in the progression of epithelial cancer. Our aim is to investigate the correlation between the expression of 8 EMT-related proteins (E-cadherin, ß-catenin, claudin-1, CD44, N-cadherin, fibronectin, vimentin, S100A4) and the clinicopathologic features of CRC in Taiwan, along with the DNA CpG epigenetic status of CD44 gene. In immunohistochemical assessment, decreased expression of E-cadherin is statistically associated with the progression of cancer stage, while decreased expression of claudin-1 as well as increased ß-catenin nuclear translocation and N-cadherin expression is statistically associated with the progression of histopathologic grade. E-cadherin, nuclear ß-catenin and claudin-1 are also associated with other important prognostic factors, including nodal metastasis, tumor deposits, and elevated serum CA 19-9 levels. In addition, the left-sided colon and rectal cancers show increased nuclear translocation of ß-catenin compared to the right-sided colon cancers, while the rectal cancers show increased fibronectin expression compared to the right-sided and left-sided colon cancers. Moreover, vimentin is aberrantly expressed in one case of signet-ring cell carcinoma. The DNA methylation levels of CD44 gene promoter between the tumoral and non-tumorous tissues by NGS comparison showed statistical difference on six CpG sites. However, such difference may not be sufficient because these DNA methylation proportions are too low to inactivate CD44 gene. Our results demonstrate the expression of E-cadherin, claudin-1, and nuclear ß-catenin is closely related to the clinicopathologic prognostic determinants of CRC in Taiwan. The DNA methylation level of CD44 gene and its protein expression, however, show no correlation with the clinicopathologic features in CRC.

5.
World J Clin Cases ; 9(15): 3487-3497, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34046449

RESUMO

Coronavirus disease 2019 (COVID-19) combined with liver injury has become a very prominent clinical problem. Due to the lack of a clear definition of liver injury in patients with COVID-19, the different selection of evaluation parameters and statistical time points, there are the conflicting conclusions about the incidence rate in different studies. The mechanism of COVID-19 combined with liver injury is complicated, including the direct injury of liver cells caused by severe acute respiratory syndrome coronavirus 2 replication and liver injury caused by cytokines, ischemia and hypoxia, and drugs. In addition, underlying diseases, especially chronic liver disease, can aggravate COVID-19 liver injury. In the treatment of COVID-19 combined with liver injury, the primary and basic treatment is to treat the etiology and pathogenesis, followed by support, liver protection, and symptomatic treatment according to the clinical classification and severity of liver injury. This article evaluates the incidence, pathogenesis and prevention and treatment of COVID-19 combined with liver injury, and aims to provide countermeasures for the prevention and treatment of COVID-19 combined with liver injury.

6.
J Acoust Soc Am ; 149(4): 2659, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33940909

RESUMO

Click-evoked otoacoustic emissions (CEOAEs) are clinically used as an objective way to infer whether cochlear functions are normal. However, because the sound pressure level of CEOAEs is typically much lower than the background noise, it usually takes hundreds, if not thousands, of repetitions to estimate the signal with sufficient accuracy. In this paper, we propose to improve the signal-to-noise ratio (SNR) of CEOAE signals within limited measurement time by optimal shrinkage (OS) in two different settings: covariance-based optimal shrinkage (cOS) and singular value decomposition-based optimal shrinkage (sOS). By simulation, the cOS consistently enhanced the SNR by 1-2 dB from a baseline method that is based on calculating the median. In real data, however, the cOS cannot enhance the SNR over 1 dB. The sOS achieved a SNR enhancement of 2-3 dB in simulation and demonstrated capability to enhance the SNR in real recordings. In addition, the level of enhancement increases as the baseline SNR decreases. An appealing property of OS is that it produces an estimate of all single trials. This property makes it possible to investigate CEOAE dynamics across a longer period of time when the cochlear conditions are not strictly stationary.


Assuntos
Ruído , Emissões Otoacústicas Espontâneas , Estimulação Acústica , Cóclea , Razão Sinal-Ruído , Fatores de Tempo
7.
Int J Mol Sci ; 22(6)2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33802702

RESUMO

Our previous study demonstrated that the glutathione S-transferase Mu 5 (GSTM5) gene is highly CpG-methylated in bladder cancer cells and that demethylation by 5-aza-dC activates GSTM5 gene expression. The aim of the present study was to investigate the role of GSTM5 in bladder cancer. The levels of GSTM5 gene expression and DNA methylation were analyzed in patients with bladder cancer, and functional studies of GSTM5 were conducted using GSTM5 overexpression in cultured bladder cancer cells. Clinical analysis revealed that the GSTM5 mRNA expression was lower in bladder cancer tissues than in normal tissues and that the level of GSTM5 DNA methylation was higher in bladder cancer tissues than in normal urine pellets. Overexpression of GSTM5 decreased cell proliferation, migration and colony formation capacity. Glutathione (GSH) assay results indicated that cellular GSH concentration was decreased by GSTM5 expression and that GSH supplementation reversed the decrease in proliferation and migration of cells overexpressing GSTM5. By contrast, a GSH synthesis inhibitor significantly decreased 5637 cell GSH levels, survival and migration. Furthermore, GSTM5 overexpression inhibited the adhesion of cells to the extracellular matrix protein fibronectin. To elucidate the effect of GSTM5 on anticancer drugs used to treat bladder cancer, cellular viability was compared between cells with or without GSTM5 overexpression. GSTM5-overexpressed cells showed no significant change in the cytotoxicity of cisplatin or mitomycin C in 5637, RT4 and BFTC 905 cells. Though a degree of resistance to doxorubicin was noted in 5637 cells overexpressing GSTM5, no such resistance was observed in RT4 and BFTC 905 cells. In summary, GSTM5 plays a tumor suppressor role in bladder cancer cells without significantly affecting chemoresistance to cisplatin and mitomycin C, and the cellular GSH levels highlight a key mechanism underlying the cancer inhibition effect of GSTM5. These findings suggest that low gene expression and high DNA methylation levels of GSTM5 may act as tumor markers for bladder cancer.


Assuntos
Antineoplásicos/metabolismo , Biomarcadores Tumorais/metabolismo , Glutationa Transferase/metabolismo , Neoplasias da Bexiga Urinária/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Butionina Sulfoximina/farmacologia , Adesão Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Cisplatino/farmacologia , Metilação de DNA/efeitos dos fármacos , Metilação de DNA/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Doxorrubicina/farmacologia , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Glutationa Transferase/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mitomicina/farmacologia , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Caracteres Sexuais , Neoplasias da Bexiga Urinária/genética
8.
Theranostics ; 11(6): 2788-2805, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33456573

RESUMO

Lipin 1 is an intracellular protein acting as a phosphatidic acid phosphohydrolase enzyme controlling lipid metabolism. Human recessive mutations in LPIN1 cause recurrent, early-onset myoglobinuria, a condition normally associated with muscle pain and weakness. Whether and how lipin 1 deficiency in humans leads to peripheral neuropathy is yet unclear. Herein, two novel compound heterozygous mutations in LPIN1 with neurological disorders, but no myoglobinuria were identified in an adult-onset syndromic myasthenia family. The present study sought to explore the pathogenic mechanism of LPIN1 in muscular and neural development. Methods: The clinical diagnosis of the proband was compared to the known 48 cases of LPIN1 recessive homozygous mutations. Whole-exome sequencing was carried out on the syndromic myasthenia family to identify the causative gene. The pathogenesis of lipin 1 deficiency during somitogenesis and neurogenesis was investigated using the zebrafish model. Whole-mount in situ hybridization, immunohistochemistry, birefringence analysis, touch-evoke escape response and locomotion assays were performed to observe in vivo the changes in muscles and neurons. The conservatism of the molecular pathways regulated by lipin 1 was evaluated in human primary glioblastoma and mouse myoblast cells by siRNA knockdown, drug treatment, qRT-PCR and Western blotting analysis. Results: The patient exhibited adult-onset myasthenia accompanied by muscle fiber atrophy and nerve demyelination without myoglobinuria. Two novel heterozygous mutations, c.2047A>C (p.I683L) and c.2201G>A (p.R734Q) in LPIN1, were identified in the family and predicted to alter the tertiary structure of LPIN1 protein. Lipin 1 deficiency in zebrafish embryos generated by lpin1 morpholino knockdown or human LPIN1 mutant mRNA injections reproduced the myotomes defects, a reduction both in primary motor neurons and secondary motor neurons projections, morphological changes of post-synaptic clusters of acetylcholine receptors, and myelination defects, which led to reduced touch-evoked response and abnormalities of swimming behaviors. Loss of lipin 1 function in zebrafish and mammalian cells also exhibited altered expression levels of muscle and neuron markers, as well as abnormally enhanced Notch signaling, which was partially rescued by the specific Notch pathway inhibitor DAPT. Conclusions: These findings pointed out that the compound heterozygous mutations in human LPIN1 caused adult-onset syndromic myasthenia with peripheral neuropathy. Moreover, zebrafish could be used to model the neuromuscular phenotypes due to the lipin 1 deficiency, where a novel pathological role of over-activated Notch signaling was discovered and further confirmed in mammalian cell lines.


Assuntos
Neurônios Motores/metabolismo , Junção Neuromuscular/metabolismo , Fosfatidato Fosfatase/deficiência , Peixe-Zebra/metabolismo , Animais , Biomarcadores/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Glioblastoma/genética , Glioblastoma/metabolismo , Células HEK293 , Humanos , Camundongos , Músculo Esquelético/metabolismo , Mutação/genética , Mioblastos/metabolismo , Mioglobinúria/genética , Mioglobinúria/metabolismo , Neurônios/metabolismo , Fosfatidato Fosfatase/genética , Receptores Notch/metabolismo , Transdução de Sinais/genética , Peixe-Zebra/genética
9.
BMC Microbiol ; 21(1): 7, 2021 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-33407119

RESUMO

BACKGROUND: Working in an underground tunnel environment is unavoidable in professions such as miners and tunnel workers, and there is a concern about the health of these workers. Few studies have addressed alterations in the intestinal microbiome of workers within that environment. RESULTS: Fecal samples were collected from the workers before they entered the tunnel (baseline status, BS) and after they left the tunnel (exposed status, ES), respectively (a time period of 3 weeks between them). We analyzed 16S rRNA sequencing to show the changes in microbial composition and self-evaluation of mental health questionnaire was also performed. The results showed that Shannon and Simpson indices decreased significantly from BS to ES. A higher abundance was found in the phylum Actinobacteria, classes Actinobacteria and Deltaproteobacteria, orders Bifidobacteriales, Coriobacteriales, and Desulfovibrionales, families Bifidobacteriaceae, Peptostreptococcaceae, Coriobacteriaceae, Clostridiaceae_1, Desulfovibrionaceae, Pseudomonadaceae, and Microbacteriaceae, and genera Bifidobacterium, Romboutsia, Clostridium sensu stricto, and Leucobacter in ES, while BS showed greater levels of genera Faecalibacterium and Roseburia. The self-evaluation showed that at least one-half of the tunnel workers experienced one or more symptoms of mental distress (inattention, sleeplessness, loss of appetite, headache or dizziness, irritability) after working in the underground tunnel environment. CONCLUSIONS: Collectively, the underground tunnel environment led to alterations in the intestinal microbiome, which might be relevant to symptoms of mental distress in underground-tunnel workers.

10.
Sci Total Environ ; 751: 141703, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32882553

RESUMO

Ammonium removal in wastewater treatment plants requires a large number of energy input, such as aeration and the addition of organics. Alternative, more economical technologies for nitrogen removal from wastewater are required. This study comprehensively investigated the feasible of microbial electricity coupled with Fe(III) reduction promoting the anaerobic ammonium removal. It was found that electrostimulation coupled with Fe(III) reduction (bioelectrochemical systems-Fe(III) (BES-Fe(III)) reactor) enhanced the anaerobic ammonium removal by 50.38% and 38.8% compared with the BES reactor and Fe(III) reactor, respectively. The ammonium removal rate reached the highest value of 80.62 ± 0.26 g N m-3·d-1 in the Fe(III)-BES reactor comparable to conventional wastewater treatment plants (WWWTPs). The improvement of ammonium removal might be the synergistic effect of BES and Feammox process on reaction process and microorganisms. Firstly, the addition of Fe2O3 could improve the electrochemical characteristics by enriching iron-reducing bacterial (FeRB). Secondly, the improved ammonium removal could be due to nitrite generated from Feammox process driving the anodic ammonium oxidation. Additionally, the ammonium removal improvement might be the effect of BES on the Fe2+ leaching so as to accelerate the Fe (II)/Fe(III) cycle. In agreement, higher abundance of FeRB and iron-oxidizing bacteria was detected in the Fe(III)-BES reactor. This study provides a lower energy consumption and operational cost technology compared with the conventional partial nitrification/denitrification, which was more than 800 times less than for the conventional wastewater treatment.


Assuntos
Compostos de Amônio , Terapia por Estimulação Elétrica , Anaerobiose , Reatores Biológicos , Desnitrificação , Compostos Férricos , Nitrogênio/análise , Oxirredução , Águas Residuárias
11.
Phys Rev Lett ; 125(23): 236102, 2020 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-33337177

RESUMO

The interplay between interlayer van der Waals interaction and intralayer lattice distortion can lead to structural reconstruction in slightly twisted bilayer graphene (TBG) with the twist angle being smaller than a characteristic angle θ_{c}. Experimentally, the θ_{c} is demonstrated to be very close to the magic angle (θ≈1.08°). Here we address the transition between reconstructed and unreconstructed structures of the TBG across the magic angle by using scanning tunneling microscopy (STM). Our experiment demonstrates that both structures are stable in the TBG around the magic angle. By using a STM tip, we show that the two structures can be changed to each other and a triangular network of chiral one-dimensional states hosted by domain boundaries can be switched on and off. Consequently, the bandwidth of the flat band, which plays a vital role in the emergent strongly correlated states in the magic angle TBG, is tuned. This provides an extra control knob to manipulate the exotic electronic states of the TBG near the magic angle.

12.
Biomed Environ Sci ; 33(10): 735-744, 2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33228832

RESUMO

Objective: Despite the remarkable progress in efforts to control disease spread, the nationwide elimination of hepatitis B in China is still hindered by the persistently high rate of hepatitis B virus (HBV) infection in Western China. This study aimed to evaluate the strategy of hepatitis B prevention and control in Western China and identify potential areas and strategies for improvement. Methods: Susceptible population vaccination, health education, professional training of doctors, and other prevention and control measures have been implemented in Wuwei city since 2010. Data were obtained from three representative cross-sectional serosurveys conducted in 2010, 2013, and 2015. The serum samples were subjected to enzyme-linked immunosorbent assays to detect the following seromarkers: HBV surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs), and antibody against hepatitis B core antigen (anti-HBc). Estimates of variance were determined using Taylor series linearization methods. Results: The three serosurveys revealed decreases in the prevalence of HBsAg (7.19% in 2010 vs. 6.51% in 2013 vs. 5.87% in 2015) and anti-HBc positivity (43.89% vs. 32.87% vs. 28.46%) and an increase in the prevalence of anti-HBs positivity (49.07% vs. 53.66% vs. 53.72%) over time. From 2010 to 2015, the legally reported incidence of hepatitis B in Wuwei city decreased from 686.53/100,000 to 53.72/100,000. Notably, persistently high HBsAg-positive rates (above 5.40%) were observed among subjects aged 20-69 years old in the three serosurveys; the prevalence of HBsAg was above 1% among children younger than 10 years old. Furthermore, rural subjects had higher rates of HBsAg and anti-HBc positivity than their urban counterparts (6.04% vs. 4.83% and 30.26% vs. 20.35%, respectively) in 2015 but had a lower rate of anti-HBs positivity (49.68 vs. 55.18%). Multivariate regression analysis showed that age, urban and rural areas, and education level were the main factors affecting HBV infection. Conclusion: Although vaccine-based prevention and control measures reduced the rate of HBV infection in Wuwei City over time, the hepatitis B infection rate in children younger than 10 years was still higher than the national average level. Therefore, the prevention and control of mother-to-child transmission and the management of the infected should be the focus of future prevention and control work.


Assuntos
Controle de Doenças Transmissíveis/estatística & dados numéricos , Vírus da Hepatite B/isolamento & purificação , Hepatite B/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , China/epidemiologia , Controle de Doenças Transmissíveis/métodos , Estudos Transversais , Feminino , Hepatite B/sangue , Hepatite B/epidemiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Soroepidemiológicos , Adulto Jovem
13.
ACS Nano ; 14(10): 13081-13090, 2020 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-33052664

RESUMO

In the magic-angle twisted bilayer graphene (MA-TBG), strong electron-electron (e-e) correlations caused by the band-flattening lead to many exotic quantum phases such as superconductivity, correlated insulator, ferromagnetism, and quantum anomalous Hall effects, when its low-energy van Hove singularities (VHSs) are partially filled. Here our high-resolution scanning tunneling microscope and spectroscopy measurements demonstrate that the e-e correlation in a nonmagic-angle TBG with a twist angle θ = 1.49° still plays an important role in determining its electronic properties. Our most interesting observation on that sample is when one of its VHSs is partially filled, the one associated peak in the spectrum splits into four peaks. Simultaneously, the spatial symmetry of electronic states around the split VHSs is broken by the e-e correlation. Our analysis based on the continuum model suggests that such a one-to-four split of the VHS originates from the formation of an interaction-driven spin-valley-polarized metallic state near the VHS, which is a symmetry-breaking phase that has not been identified in the MA-TBG or in other systems.

14.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 51(4): 578-581, 2020 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-32691571

RESUMO

Objective: To investigate the monitoring effect and application of transcranial Doppler ultrasound (TCD) in patients with severe neurovascular cerebrovascular diseases. Methods: From December 2016 to October 2018, 96 patients with cerebrovascular disease in Department of Neurology and ICU, West China Hospital, Sichuan University were monitored by bedside TCD, including the detection of bilateral middle cerebral arteries (MCAs) through temporal window, and the detection of the basilar artery (BA) through occipital window, characterized by the peak systolic blood flow velocity, peak diastolic blood flow velocity, average peak blood flow velocity, vascular pulsatility index, vascular pulsatility index, vascular resistance index and blood flow spectrum morphology in local hemodynamic changes. According to the monitoring results, it was divided into vasospasm group, increased blood flow group and insufficient blood supply group. Relevant data of monitoring results were analysed. Results: Bedside TCD monitoring was successfully used to all cerebrovascular diseases patients. Among 96 patients, 37 patients (38.54%) had increased cerebral blood flow, 15 patients (15.62%) had cerebral vasospasm, and 93 patients had insufficient cerebral blood supply (90.62%, including insufficient blood supply to the MCA and BA). Patients mainly with cerebral aneurysm and hypertensive intracerebral hemorrhage types contributed the highest proportion of insufficient blood supply, followed by the increase of blood flow, and the incidence of vasospasm was relatively low. In cerebral aneurysm group and hypertensive intracerebral hemorrhage group, and differences in the incidence of insufficient blood supply, increased blood flow, and vasospasm were statistically significant ( P<0.05). Conclusion: The bedside TCD monitoring can assess the patient's craniocerebral hemodynamic information and provide a clinical guidance.


Assuntos
Transtornos Cerebrovasculares , Ultrassonografia Doppler Transcraniana , Vasoespasmo Intracraniano , Velocidade do Fluxo Sanguíneo , Transtornos Cerebrovasculares/diagnóstico por imagem , China , Humanos , Hemorragia Subaracnóidea , Vasoespasmo Intracraniano/diagnóstico por imagem
15.
Phys Rev Lett ; 124(16): 166801, 2020 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-32383950

RESUMO

Berry phase, the geometric phase accumulated over a closed loop in parameter space during an adiabatic cyclic evolution, has been demonstrated to play an important role in many quantum systems since its discovery. In gapped Bernal bilayer graphene, the Berry phase can be continuously tuned from zero to 2π, which offers a unique opportunity to explore the tunable Berry phase on physical phenomena. Here, we report experimental observation of Berry-phase-induced valley splitting and crossing in movable bilayer-graphene p-n junction resonators. In our experiment, the resonators are generated by combining the electric field of a scanning tunneling microscope tip with the gap of bilayer graphene. A perpendicular magnetic field changes the Berry phase of the confined bound states in the resonators from zero to 2π continuously and leads to the Berry phase difference for the two inequivalent valleys in the bilayer graphene. As a consequence, we observe giant valley splitting and unusual valley crossing of the lowest bound states. Our results indicate that the bilayer-graphene resonators can be used to manipulate the valley degree of freedom in valleytronics.

16.
Medicine (Baltimore) ; 99(11): e19284, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32176052

RESUMO

High levels of albuminuria have been demonstrated to associate with hearing loss in non-diabetic people, while the clinical impact of low-grade albuminuria has attracted less attention. This cross-sectional population-based study aimed to examine whether hearing loss in non-diabetic United States (US) adults is independently associated with low-grade albuminuria or reduced estimated glomeruli filtration rate (eGFR).A total of 2518 participants aged 20 to 69 years were selected from the US National Health and Nutritional Examination Survey database. Participants with diabetes or high-grade albuminuria were excluded. Hearing loss was assessed using low-frequency pure-tone average (LFPTA) thresholds (0.5, 1.0, 2.0 kHz) and high-frequency pure-tone average (HFPTA) thresholds (3.0, 4.0, 6.0, 8.0 kHz). Logistic and linear regression analyses were used to evaluate associations between renal function indicators and hearing loss.The median age of included participants was 37.4 years, and 55% of them were female. Multivariate analysis revealed that participants with urinary albumin-to-creatinine ratio (UACR) in the highest tertile had a significantly higher risk of hearing loss (OR, 1.79; 95% CI, 1.01-3.19) and higher HFPTA thresholds (ß: 2.23; SE: 0.77). Participants with eGFR <60 mL/min/1.73 m had higher LFPTA thresholds (ß: 4.31; SE: 1.79). After stratification by sex, a significant risk remained only for males in the highest UACR tertile, with 2.18 times the risk of hearing loss (95% CI, 1.06-4.48).Non-diabetic US males with low-grade albuminuria are at increased risk of hearing loss, independent of eGFR.


Assuntos
Albuminúria/complicações , Albuminúria/diagnóstico , Comorbidade , Perda Auditiva/epidemiologia , Perda Auditiva/etiologia , Adulto , Distribuição por Idade , Idoso , Audiometria/métodos , Glicemia/análise , Estudos Transversais , Diabetes Mellitus , Taxa de Filtração Glomerular , Perda Auditiva/diagnóstico , Humanos , Incidência , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Inquéritos Nutricionais , Valores de Referência , Medição de Risco , Índice de Gravidade de Doença , Estados Unidos , Urinálise/métodos
17.
Acta Otolaryngol ; 140(3): 230-235, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32003266

RESUMO

Background: Fluctuating hearing loss is characteristic of Ménière's disease (MD) during acute episodes. However, no reliable audiometric hallmarks are available for counselling the hearing recovery possibility.Aims/objectives: To find parameters for predicting MD hearing outcomes.Material and methods: We applied machine learning techniques to analyse transient-evoked otoacoustic emission (TEOAE) signals recorded from patients with MD. Thirty unilateral MD patients were recruited prospectively after onset of acute cochleo-vestibular symptoms. Serial TEOAE and pure-tone audiogram (PTA) data were recorded longitudinally. Denoised TEOAE signals were projected onto the three most prominent principal directions through a linear transformation. Binary classification was performed using a support vector machine (SVM). TEOAE signal parameters, including signal energy and group delay, were compared between improved (PTA improvement: ≥15 dB) and nonimproved groups using Welch's t-test.Results: Signal energy did not differ (p = .64) but a significant difference in 1-kHz (p = .045) group delay was recorded between improved and nonimproved groups. The SVM achieved a cross-validated accuracy of >80% in predicting hearing outcomes.Conclusions and significance: This study revealed that baseline TEOAE parameters obtained during acute MD episodes, when processed through machine learning technology, may provide information on outer hair cell function to predict hearing recovery.


Assuntos
Potenciais Evocados Auditivos , Células Ciliadas Auditivas Externas/fisiologia , Perda Auditiva Neurossensorial/fisiopatologia , Aprendizado de Máquina , Doença de Meniere/fisiopatologia , Doença Aguda , Perda Auditiva Neurossensorial/etiologia , Humanos , Doença de Meniere/complicações , Prognóstico , Estudos Prospectivos
18.
Molecules ; 25(3)2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-32033326

RESUMO

The objective of this study was to synthesize the 9-/13-position substituted berberine derivatives and evaluate their cytotoxic and photocytotoxic effects against three human cancer cell lines. Among all the synthesized compounds, 9-O-dodecyl- (5e), 13-dodecyl- (6e), and 13-O-dodecyl-berberine (7e) exhibited stronger growth inhibition against three human cancer cell lines, (HepG2, HT-29 and BFTC905), in comparison with structurally related berberine (1). These three compounds also showed the photocytotoxicity in human cancer cells in a concentration-dependent and light dose-dependent manner. Through flow cytometry analysis, we found out a lipophilic group at the 9-/13-position of berberine may have facilitated its penetration into test cells and hence enhanced its photocytotoxicity on the human liver cancer cell HepG2. Further, in cell cycle analysis, 5e, 6e, and 7e induced HepG2 cells to arrest at the S phase and caused apoptosis upon irradiation. In addition, photodynamic treatment of berberine derivatives 5e, 6e, and 7e again showed a significant photocytotoxic effects on HepG2 cells, induced remarkable cell apoptosis, greatly increased intracellular ROS level, and the loss of mitochondrial membrane potential. These results over and again confirmed that berberine derivatives 5e, 6e, and 7e greatly enhanced photocytotoxicity. Taken together, the test data led us to conclude that berberine derivatives with a dodecyl group at the 9-/13-position could be great candidates for the anti-liver cancer medicines developments.


Assuntos
Antineoplásicos/farmacologia , Berberina , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Antineoplásicos/síntese química , Apoptose/efeitos dos fármacos , Berberina/análogos & derivados , Berberina/síntese química , Berberina/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células HT29 , Células Hep G2 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Pontos de Checagem da Fase S do Ciclo Celular/efeitos dos fármacos
19.
J Org Chem ; 84(24): 16254-16261, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31777249

RESUMO

An efficient approach to access functionalized tertiary-type ß-hydroxyl carboxamides has been developed through Sc(OTf)3-catalyzed addition of ynamides and substituted ketones. Water was found to be an important reaction substrate, and the solvent was not needed in this process. A broad range of substituted ynamides and ketones was well applicable to the reaction with excellent chemical selectivities. Moreover, several chiral ß-hydroxyl carboxamides 3j-3r were prepared with excellent regioselectivities and outstanding diastereoselectivities.

20.
Chem Commun (Camb) ; 55(94): 14170-14173, 2019 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-31701971

RESUMO

A zinc-catalyzed decarboxylative A3 reaction of cyclic amino acids, α,ß-unsaturated aldehydes and terminal alkynes has been developed. A series of functionalized N-heterocyclic 1,6-enynes have been successfully obtained with excellent regioselectivities through this novel approach. In addition, the utility of this straightforward process is demonstrated by the preparation of a polycyclic nitrogen-containing heterocyclic compound.

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