o 10
Recently Published Documents


TOTAL DOCUMENTS

516
(FIVE YEARS 133)

H-INDEX

28
(FIVE YEARS 4)

2022 ◽  
Vol 509 (2) ◽  
Author(s):  
Trịnh Đắc Chung ◽  
Nguyễn Thị Tố Uyên
Keyword(s):  

Sử dụng phương pháp mô tả từng trường hợp có can thiệp nhằm đánh giá kết quả sau tạo hình hệ thống xương con và phục hồi màng nhĩ bằng sụn. Kết quả: Tuổi thường gặp 40,06  ± 11.06 tuổi. Nữ nhiều hơn nam. Triệu chứng cơ năng thường gặp ù tai, nghe kém. Nội soi tai 50% viêm tai dính toàn bộ, 50% viêm tai dính khu trú. Thính lực trước phẫu thuật ngưỡng nghe đường xương là 15,78 ± 12,50 dB, PTA trung bình trước phẫu thuật là 43,36±17,45 dB, chỉ số ABG trước phẫu thuật là 27,65±13,71 dB. Chụp cắt lớp vi tính chuỗi xương con liên tục ở 10/16 BN chiếm 62,5%, chuỗi xương con bị gián đoạn ở 6/16 BN chiếm 37,5%. Tổn thương xương con trong viêm tai dính: 100% tổn thương xương đe, 31,25% tổn thương cả hỗn hợp búa đe, không có trường hợp nào tổn thương cả 3 xương con. Phục hồi màng nhĩ bằng sụn và màng sụn trong 81,25%, kết hợp sụn và cân cơ thái dương trong 18,75% trường hợp. Thời gian theo dõi trung bình sau phẫu thuật là 9,6 ± 7,2 tháng. Sau mổ 75% cải thiện tình trạng ù tai và nghe kém. Ngưỡng nghe đường khí trung bình sau phẫu thuật là 33,59 ± 14,90 dB, chỉ số ABG sau phẫu thuật là 23,98 ± 14,3 dB. Kết luận: Phẫu thuật tạo hình hệ thống xương con và phục hồi màng nhĩ bằng sụn là phương pháp căn bản điều trị viêm tai dính và tái tạo chức năng nghe.


2021 ◽  
Author(s):  
Bastian Kirsch ◽  
Cathy Hohenegger ◽  
Daniel Klocke ◽  
Felix Ament
Keyword(s):  

<p>Cold Pools sind mesoskalige Gebiete kalter und dichter Luftmassen, die durch Verdunstung von Hydrometeoren unterhalb regnender Wolken entstehen. Während die kalte Luft absinkt und sich als Dichteströmung an der Erdoberfläche ausbreitet, löst sie durch Hebung an ihrer Vorderseite häufig neue Konvektion aus oder forciert den Übergang von flacher zu tiefer Konvektion. Viele modellbasierte Arbeiten belegen die Bedeutung von Cold Pools für die Organisation von Konvektion. Operationelle Messnetze mit einer typischen Maschenweite von 25 km hingegen sind blind für sub-mesoskalige (O(100) m — O(10) km) Prozesse wie Cold Pools und erlauben somit weder die Untersuchung noch die Validierung ihrer raum-zeitlichen Struktur.</p> <p>Im Rahmen der Messkampagne FESST@HH wurde von Juni bis August 2020 im Großraum Hamburg (50 km × 35 km) ein dichtes Netz bestehend aus 103 meteorologischen Messstationen betrieben. Das Rückgrat des Messnetzes bildeten 82 eigens für diesen Zweck entwickelte und gebaute APOLLO-Stationen (Autonomous cold POoL LOgger), die Lufttemperatur und -druck mit trägheitsarmen Sensoren in sekündlicher Auflösung messen. Das Netzwerk wurde mit 21 Wetterstationen ergänzt, die zusätzlich Luftfeuchte, Windgeschwindigkeit und Niederschlag in 10-sekündiger Auflösung aufzeichnen und auf kommerziellen Sensoren basieren. Ein besonderes Merkmal von FESST@HH ist, dass die Durchführung der Kampagne während der COVID19-Pandemie nur durch eine große Zahl Freiwilliger ermöglicht wurde, die kurzfristig Messstandorte bereitgestellt und die Betreuung der Instrumente unterstützt haben.</p> <p>Wir präsentieren die neuartigen Messinstrumente und den Datensatz der FESST@HH-Kampagne (DOI: 10.25592/UHHFDM.8966). Ein Fallbeispiel zeigt, dass das dichte Messnetz in der Lage ist sowohl die horizontale Heterogenität des Temperaturfeldes innerhalb eines Cold Pools als auch seine Größe und Ausbreitungsgeschwindigkeit während verschiedener Phasen des Lebenszyklus abzubilden. Darüber hinaus erlauben die Messungen einen neuen Blick auf weitere Quellen sub-mesoskaliger Variabilität wie die nächtliche städtische Wärmeinsel und die Variation turbulenter Temperaturfluktuationen als Ausdruck charakteristischer Standorteigenschaften.</p>


2021 ◽  
Vol 10 (16) ◽  
pp. e294101623772
Author(s):  
Nágila Iane Pacheco ◽  
Luiza Aragão Paiva Pires Ferreira Mendes ◽  
Gabriel de Sousa Carneiro ◽  
Mariana Pacheco de Sousa ◽  
Jucilene da Silva Sousa ◽  
...  
Keyword(s):  

Introdução: A Organização Mundial de Saúde em 2020 declarou a pandemia do SARS-CoV-2, que apresenta alta transmissibilidade causando uma síndrome respiratória aguda fatal. Outrossim, uma doença rara e mortal, além do citado a cima, provada por um vírus é o do Ebola em primatas (incluído o homem), constituem como mais mortífero e disseminado nos surtos globais. Objetivo: estabelecer a comparação entre o coronavirus e o ebola com foco na mortalidade e letalidade. Metodologia: uma revisão integrativa da literatura, utilizando bancos de dados online como: BVS, SCIELO, PUBMED, MEDLINE, WHO, IDRC, MS, CDC. Resultado e Discussões: Em 2020, ocorreu o 10° surto de Ebola e a 2° maior desde sua descoberta em 1976, notificou-se 3.470 casos. Atualmente em 2021, conforme a Semana Epidemiológica (SE) 43, em 30 de outubro, confirmou-se 246.407.251 casos de COVID-19 no mundo. Comparando o coronavírus, que possui sua letalidade de 6,1% das pessoas eivadas, com a ameaça do Ebola vírus, abrangendo 90%, considera-se mais agravante, por ocasionar rapidamente as mortes dos enfermos. Conclusão: Dessa forma, a COVID-19 e o Ebola são vírus de ameaças a saúde pública global, devido as suas elevadas taxas de morbidade e mortalidade. Contudo, carece seguir os protocolos e as recomendações da Organização Mundial da Saúde no controle e prevenção das enfermidades.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
Georges Azuelos ◽  
Oliver Fischer ◽  
Sudip Jana

AbstractB-Physics anomalies have recently raised renewed interest in leptoquarks, predicted in several theoretical frameworks. Under simplifying but conservative assumptions, we show that the current limits from LHC searches together with the requirement to explain the observed value for $$R_{D^{(*)}}$$ R D ( ∗ ) constrain the $$R_2$$ R 2 leptoquark mass to be in the range of $$800 \le m_{R_2} \le 1000$$ 800 ≤ m R 2 ≤ 1000  GeV. We study the search for $$R_2$$ R 2 at the LHeC via its resonance in the $$b\tau $$ b τ final state by performing a cut-and-count analysis of the signal and the dominant Standard Model backgrounds. We find that the LHeC has an excellent discovery potential for the $$R_2$$ R 2 leptoquark even for couplings to the first generation as small as $${\mathcal {O}}(10^{-2})$$ O ( 10 - 2 ) .


2021 ◽  
Vol 944 (1) ◽  
pp. 012053
Author(s):  
I Y Sani ◽  
A S Atmadipoera ◽  
A Purwandana ◽  
F Syamsudin

Abstract Along the pathway, ITF water is considered to be transformed due to strong diapycnal mixing. This study aims to describe the structure of ITF water and to estimate turbulent mixing. The number of 6 CTD casts and 9 repeated CTD “yoyo” measurements were obtained from the “Years of Maritime Continent” YMC cruise (a joint cruise between BPPT/IPB/UNUD-Univ. Tokyo/JAMSTEC) and onboard R.V. Baruna Jaya IV in August 2019. The CTD datasets are processed with SBE Data Processing and analyzed for water mass composition, as well as turbulent mixing with Thorpe method. The results showed that thermocline water of NPSW with S-max, and intermediate water of NPIW with S-min from North Pacific origin are dominant. Transformation of NPSW and NPIW along their pathway can be identified from decreasing S-max of NPSW and increasing S-min of NPIW. Estimates of ϵ and Kρ are O(10−5) m2s−2 and 10−2 m2 s−1, respectively. High mixing occur also in the interior layer with the e and the Kp O(10−6) m2s−2 and O(10−1) m2 s−1, respectively. This is related to barotropic tidal activity that interacts with the bottom topography where there are many sills, causing the formation of strong baroclinic tides.


2021 ◽  
Vol 931 ◽  
Author(s):  
Peter A. Monkewitz

The scaling of different features of streamwise normal stress profiles $\langle uu\rangle ^+(y^+)$ in turbulent wall-bounded flows is the subject of a long-running debate. Particular points of contention are the scaling of the ‘inner’ and ‘outer’ peaks of $\langle uu\rangle ^+$ at $y^+\approxeq ~15$ and $y^+ ={O}(10^3)$ , respectively, their infinite Reynolds number limit, and the rate of logarithmic decay in the outer part of the flow. Inspired by the thought-provoking paper of Chen & Sreenivasan (J. Fluid Mech., vol. 908, 2021, p. R3), two terms of an inner asymptotic expansion of $\langle uu\rangle ^+$ in the small parameter $Re_{\tau }^{-1/4}$ are constructed from a set of direct numerical simulations (DNS) of channel flow. This inner expansion is for the first time matched through an overlap layer to an outer expansion, which not only fits the same set of channel DNS within 1.5 % of the peak stress, but also provides a good match of laboratory data in pipes and the near-wall part of boundary layers, up to the highest $Re_{\tau }$ values of $10^5$ . The salient features of the new composite expansion are first, an inner $\langle uu\rangle ^+$ peak, which saturates at 11.3 and decreases as $Re_{\tau }^{-1/4}$ . This inner peak is followed by a short ‘wall log law’ with a slope that becomes positive for $Re_{\tau }$ beyond ${O}(10^4)$ , leading up to an outer peak, followed by the logarithmic overlap layer with a negative slope going continuously to zero for $Re_{\tau }\to \infty$ .


2021 ◽  
Vol 931 ◽  
Author(s):  
Joran Rolland

This text presents one of the first successful applications of a rare events sampling method for the study of multistability in a turbulent flow without stochastic energy injection. The trajectories of collapse of turbulence in plane Couette flow, and their probability and rate of occurrence are systematically computed using adaptive multilevel splitting (AMS). The AMS computations are performed in a system of size $L_x\times L_z=24\times 18$ at Reynolds number $R=370$ with an acceleration by a factor ${O}(10)$ with respect to direct numerical simulations (DNS) and in a system of size $L_x\times L_z=36\times 27$ at Reynolds number $R=377$ with an acceleration by a factor ${O}(10^3)$ . The AMS results are validated by a comparison with DNS in the smaller system. Visualisations indicate that turbulence collapses because the self-sustaining process of turbulence fails locally. The streamwise vortices decay first in streamwise elongated holes, leaving streamwise invariant streamwise velocity tubes that experience viscous decay. These holes then extend in the spanwise direction. The examination of more than a thousand trajectories in the $(E_{k,x}=\int u_x^2/2\,\textrm {d}^3\boldsymbol {x},E_{k,y-z}=\int (u_y^2/2+u_z^2/2)\,\textrm {d}^3\boldsymbol {x})$ plane in the smaller system confirms the faster decay of streamwise vortices and shows concentration of trajectories. This hints at an instanton phenomenology in the large size limit. The computation of turning point states, beyond which laminarisation is certain, confirms the hole formation scenario and shows that it is more pronounced in larger systems. Finally, the examination of non-reactive trajectories indicates that both the vortices and the streaks reform concomitantly when the laminar holes close.


2021 ◽  
Vol 8 ◽  
Author(s):  
Bingtian Li ◽  
Libin Du ◽  
Shiqiu Peng ◽  
Yibo Yuan ◽  
Xiangqian Meng ◽  
...  

Modulations of internal tides (ITs) including the baroclinic tidal energy budget, the incoherency, and the nonlinear interactions among different tidal components by turbulent mixing in the South China Sea (SCS) are investigated through numerical simulations. The baroclinic tidal energy budget can hardly be affected by the structure of mixing. Meanwhile, change in the mixing intensity in a reasonable range also cannot obviously modulate the baroclinic tidal energy budget in the SCS. Compared to the baroclinic energy budget, the distributions of conversion and dissipation are more sensitive to the change of mixing. Turbulent mixing also modulates the incoherency of ITs by changing the horizontal density in the ocean. The horizontal variation of density adds incoherence to ITs largely by affecting the internal tidal amplitudes. Furthermore, nonlinear interactions among different components of ITs are generally modulated by the mixing intensity, whereas the variation of the mixing structure can hardly influence the nonlinear interactions. Therefore, the diapycnal diffusivity can set to be horizontally and vertically homogeneous in most of the internal tidal simulations, except for those in which the incoherency of ITs needs to be simulated. However, excessive strong mixing will destroy the stratification. Thus, the optimum range for IT simulations in the SCS is from O (10–5) to O (10–3) m2s–1.


2021 ◽  
Vol 8 (11) ◽  
pp. 274
Author(s):  
Zaida Zakaria ◽  
Zaidatul Akmal Othman ◽  
Joseph Bagi Suleiman ◽  
Nur Asyilla Che Jalil ◽  
Wan Syaheedah Wan Ghazali ◽  
...  

Metabolic dysfunction-associated fatty liver disease (MAFLD) is an excessive buildup of liver lipids closely associated with various kinds of undesirable metabolic effects and oxidative stress. We aimed to investigate the protective and therapeutic effects of orlistat on metabolic syndrome and oxidative stress parameters in high-fat diet (HFD) induced-MAFLD rats. Twenty-four male Sprague-Dawley rats were randomly divided into four groups (n = 6/group), i.e., Normal control (N), HFD, HFD + orlistat (HFD + O) (10 mg/kg/day administered concomitantly for 12 weeks as a protective model), and obese+orlistat (OB + O) (10 mg/kg/day administered 6 weeks after induction of obesity as a therapeutic model) groups. After 12 weeks, the HFD group had significantly increased Lee obesity index, serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, total cholesterol, triglyceride, low-density lipoprotein levels, liver total cholesterol and triglyceride levels, insulin resistance and non-alcoholic steatohepatitis (NASH) together with decreased serum high-density lipoprotein level. Additionally, the HFD group also showed increased Nrf2 translocation to the nucleus with high Keap1 expression and increased liver oxidative stress parameters. Orlistat significantly improved all these alterations in HFD rats. We demonstrated that orlistat might have protective and therapeutic effects against HFD-induced MAFLD rats by its activation on Nrf2 signaling pathway, which subsequently improved metabolic syndrome and oxidative stress parameters.


2021 ◽  
Vol 930 ◽  
Author(s):  
Markus Scherer ◽  
Markus Uhlmann ◽  
Aman G. Kidanemariam ◽  
Michael Krayer

The role of turbulent large-scale streaks or large-scale motions in forming subaqueous sediment ridges on an initially flat sediment bed is investigated with the aid of particle resolved direct numerical simulations of open channel flow at bulk Reynolds numbers up to 9500. The regular arrangement of quasi-streamwise ridges and troughs at a characteristic spanwise spacing between 1 and 1.5 times the mean fluid height is found to be a consequence of the spanwise organisation of turbulence in large-scale streamwise velocity streaks. Ridges predominantly appear in regions of weaker erosion below large-scale low-speed streaks and vice versa for troughs. The interaction between the dynamics of the large-scale streaks in the bulk flow and the evolution of sediment ridges on the sediment bed is best described as ‘top-down’ process, as the arrangement of the sediment bedforms is seen to adapt to changes in the outer flow with a time delay of several bulk time units. The observed ‘top-down’ interaction between the outer flow and the bed agrees fairly well with the conceptual model on causality in canonical channel flows proposed by Jiménez (J. Fluid Mech., vol. 842, 2018, P1, § 5.6). Mean secondary currents of Prandtl's second kind of comparable intensity and lateral spacing are found over developed sediment ridges and in single-phase smooth-wall channels alike in averages over ${O}(10)$ bulk time units. This indicates that the secondary flow commonly observed together with sediment ridges is the statistical footprint of the regularly organised large-scale streaks.


Sign in / Sign up

Export Citation Format

Share Document