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Estimation of Jones matrix,birefringence and entropy using Cloude-Pottier decomposition in polarization-sensitive optical coherence tomography: erratum

Masahiro Yamanari Satoru Tsuda Taiki Kokubun Yukihiro Shiga Kazuko Omodaka Naoko Aizawa Yu Yokoyama Noriko Himori Shiho Kunimatsu-Sanuki Kazuichi Maruyama Hiroshi Kunikata Toru Nakazawa 《Biomedical optics express》2016,7(11):4636-4638

An erratum is presented to correct errors in the equations in [Biomed. Opt. Express 7(9), 3551–3573 (2016)].OCIS codes: (110.4500) Optical coherence tomography, (170.4500) Optical coherence tomography, (170.4470) Ophthalmology, (120.2130) Ellipsometry and polarimetryIn our paper [], several errors in the equations have been found and are corrected as below.Equation (22) of [] should read

H_{n o i s e} (\underline{E_{i}}) = \sum_{j = 1}^{2} - ζ_{j}^{(i)} \log_{4} (ζ_{j}^{(i)}),

(22) where the negative sign and the base 4 of the logarithm were described correctly. We note that the same base of the logarithm has to be used for the entropy throughout the processing flow.In addition, Eq. (28) was erroneously presented in [], which algebraically resulted in 1 regardless of the signals and noises. It was related to the erroneous definition of Eq. (27) in []. Equation (27) should be defined to include the bias of the noises as

\begin{matrix} [\begin{matrix} s_{0}^{″ (1)} \\ s_{1}^{″ (1)} \\ s_{2}^{″ (1)} \\ s_{3}^{″ (1)} \end{matrix}] : = [\begin{matrix} \bar{{| g_{1H} |}^{2}} + \bar{{| g_{1V} |}^{2}} \\ \bar{{| g_{1H} |}^{2}} - \bar{{| g_{1V} |}^{2}} \\ 2 Re [\bar{g_{1H} g_{1 V}^{*}}] \\ 2 Im [\bar{g_{1H} g_{1 V}^{*}}] \end{matrix}] = [\begin{matrix} \bar{{| g_{1H} |}^{2}} + \bar{{| g_{1V} |}^{2}} \\ \bar{{| g_{1H} |}^{2}} - \bar{{| g_{1V} |}^{2}} \\ 2 Re [\bar{E_{1H} E_{1 V}^{*}}] \\ 2 Im [\bar{E_{1H} E_{1 V}^{*}}] \end{matrix}] = [\begin{matrix} \bar{{| g_{1H} |}^{2}} + \bar{{| g_{1V} |}^{2}} \\ \bar{{| g_{1H} |}^{2}} - \bar{{| g_{1V} |}^{2}} \\ 2 \bar{| E_{1H} |} \bar{| E_{1V} |} \cos δ \\ 2 \bar{| E_{1H} |} \bar{| E_{1V} |} \sin δ \end{matrix}] \\ = [\begin{matrix} \bar{{| g_{1H} |}^{2}} + \bar{{| g_{1V} |}^{2}} \\ \bar{{| g_{1H} |}^{2}} - \bar{{| g_{1V} |}^{2}} \\ 2 \sqrt{\bar{{| g_{1H} |}^{2}} - \bar{{| n_{1H} |}^{2}}} \sqrt{\bar{{| g_{1V} |}^{2}} - \bar{{| n_{1V} |}^{2}}} \cos δ \\ 2 \sqrt{\bar{{| g_{1H} |}^{2}} - \bar{{| n_{1H} |}^{2}}} \sqrt{\bar{{| g_{1V} |}^{2}} - \bar{{| n_{1V} |}^{2}}} \sin δ \end{matrix}], \end{matrix}

(27) which is based on Eq. (25) of []. Equation (28) of [] should then read

\begin{matrix} P^{(1)} = \frac{\sqrt{{s_{1}^{″ (1)}}^{2} + {s_{2}^{″ (1)}}^{2} + {s_{3}^{″ (1)}}^{2}}}{{s^{″}}_{0}^{(1)}} \\ = \frac{\sqrt{{(\bar{{| g_{1H} |}^{2}} - \bar{{| g_{1V} |}^{2}})}^{2} + 4 (\bar{{| g_{1H} |}^{2}} - \bar{{| n_{1H} |}^{2}}) (\bar{{| g_{1V} |}^{2}} - \bar{{| n_{1V} |}^{2}})}}{\bar{{| g_{1H} |}^{2}} + \bar{{| g_{1V} |}^{2}}} . \end{matrix}

(28)Consequently, Eqs. (43)-(46) of [] should read

P^{(\underline{ε_{1}})} = \frac{\sqrt{{(\bar{{| ε_{1H} |}^{2}} - \bar{{| ε_{1V} |}^{2}})}^{2} + 4 (\bar{{| ε_{1H} |}^{2}} - Var (ε_{1H})) (\bar{{| ε_{1V} |}^{2}} - Var (ε_{1V}))}}{\bar{{| ε_{1H} |}^{2}} + \bar{{| ε_{1V} |}^{2}}},

(43)

P^{(\underline{ε_{2}})} = \frac{\sqrt{{(\bar{{| ε_{2H} |}^{2}} - \bar{{| ε_{2V} |}^{2}})}^{2} + 4 (\bar{{| ε_{2H} |}^{2}} - Var (ε_{2H})) (\bar{{| ε_{2V} |}^{2}} - Var (ε_{2V}))}}{\bar{{| ε_{2H} |}^{2}} + \bar{{| ε_{2V} |}^{2}}},

(44)

P^{(\underline{ε_{1}} | \underline{ε_{2}})} = \frac{\sqrt{{(\bar{{| ε_{1H} |}^{2}} - \bar{{| ε_{1V} |}^{2}})}^{2} + 4 (\bar{{| ε_{1H} |}^{2}} - Var (ε_{1H} | \underline{ε_{2}})) (\bar{{| ε_{1V} |}^{2}} - Var (ε_{1V} | \underline{ε_{2}}))}}{\bar{{| ε_{1H} |}^{2}} + \bar{{| ε_{1V} |}^{2}}},

(45)

P^{(\underline{ε_{2}} | \underline{ε_{1}})} = \frac{\sqrt{{(\bar{{| ε_{2H} |}^{2}} - \bar{{| ε_{2V} |}^{2}})}^{2} + 4 (\bar{{| ε_{2H} |}^{2}} - Var (ε_{2H} | \underline{ε_{1}})) (\bar{{| ε_{2V} |}^{2}} - Var (ε_{2V} | \underline{ε_{1}}))}}{\bar{{| ε_{2H} |}^{2}} + \bar{{| ε_{2V} |}^{2}}} .

(46)In Eq. (28),

\bar{{| g_{1 H} |}^{2}} - \bar{{| n_{1 H} |}^{2}}

and

\bar{{| g_{1 V} |}^{2}} - \bar{{| n_{1 V} |}^{2}}

should be non-negative in principle, but can be negative in practice. If these parameters are negative in the data processing, they are set as zero to avoid physically undefined values of P⁽¹⁾. Similar operations are also applied to Eqs. (43)-(46).In addition, the last sentence of Section 2.5 shown in the following should be deleted because it was presented incorrectly and did not make sense in []; “The absolute-squared expected values of the matrix elements in Eq. (24) or (29) that are used in Eqs. (35)-(42) are calculated as

\bar{{| g_{1H} |}^{2}} - \bar{{| n_{1H} |}^{2}}

and similarly for all other elements.”Since all of the equations were correctly implemented in our processing software of [], no change is required in the results. 相似文献

Investigation of depth-resolved nanoscale structural changes in regulated cell proliferation and chromatin decondensation: erratum

Shikhar Uttam Rajan K. Bista Kevin Staton Sergey Alexandrov Serah Choi Christopher J. Bakkenist Douglas J. Hartman Randall E. Brand Yang Liu 《Biomedical optics express》2013,4(11):2491

We correct minor errors in two equations reported in our paper [Biomed. Opt. Express 4, 596–613 (2013)]; an additional factor of two was mistakenly incorporated in Eqs. (3) and (4). We give the correct equations below. All the simulations and experiments in the previous paper were performed using the correct equations, and therefore, remain the same.OCIS codes: (180.3170) Interference microscopy, (300.6300) Spectroscopy, Fourier transforms, (170.4730) Optical pathology, (170.1610) Clinical applicationsWe correct Eqs. (3) and (4) in our previous paper [] by removing the factor of two that was mistakenly incorporated in both of them. The correct versions of Eqs. (3) and (4) respectively are,

p (z_{opl}) = 2 Γ \otimes [(R_{r} + R_{s}) δ (0) + 2 r_{r} ℱ^{- 1} (\int_{0}^{Z} r_{s} (z^{''}) \cos (4 π \frac{K}{2} n (z^{''}) z^{''}) d z^{''})] (z_{o p l}),

(3)and,

δ p (z_{opl}) = \frac{λ_{0}}{2 π} \arctan (\frac{Im (p (z_{opl}))}{Re (p (z_{opl}))}), z_{o p l} \neq 0.

(4)In Eq. (3), the convolution argument has been changed from 2z_opl to z_opl, and in Eq. (4), the factor of two has been removed from the denominator. The reason for the deletion, also explained in our original paper [], is that the factor of two is implicitly incorporated within the spatial frequency K = (k_s – k _i)/2π = 2(k/2π) z = (k/π) z, under the normal illumination and collection geometry for the common-path setup, thereby allowing us to directly perform the Fourier transform at the optical depth location of z_opl. The simulation and experimental results reported in the paper remain unaltered, as they were performed using the correct equations. 相似文献

Optical theorem for acoustic non-diffracting beams and application to radiation force and torque: erratum

Likun Zhang Philip L. Marston 《Biomedical optics express》2013,4(12):2988

We correct minor errors in four equations in our recent paper [Biomed. Opt. Express 4(9), 1610–1617 (2013)]. They are equations (11), (14), (15), and (17) therein, where a factorial ratio

\frac{(n - m)!}{(n + m)!}

was mistakenly omitted. All the other equations and analysis in the paper were correct.OCIS codes: (350.4855) Optical tweezers or optical manipulation, (290.2200) Extinction, (290.4020) Mie theory, (290.5850) Scattering, particlesWe correct a factor

\frac{(n - m)!}{(n + m)!}

that was mistakenly omitted in four equations in our recent paper []. They are Eqs. (11), (14), (15), and (17) in []. The correct versions of these four equations respectively are,

σ_{ext} = \frac{π}{k^{2}} \sum_{n = | m |}^{\infty} (2 n + 1) \frac{(n - m)!}{(n + m)!} {[P_{n}^{m} (cos β)]}^{2} Re [2 (1 - s_{n})],

(11)

Q_{sca} \equiv σ_{sca} / (π a^{2}) = \frac{1}{{(k a)}^{2}} \sum_{n = | m |}^{\infty} (2 n + 1) \frac{(n - m)!}{(n + m)!} {[P_{n}^{m} (cos β)]}^{2} ({| s_{n} - 1 |}^{2}),

(14)

Q_{abs} \equiv σ_{abs} / (π a^{2}) = \frac{1}{{(k a)}^{2}} \sum_{n = | m |}^{\infty} (2 n + 1) \frac{(n - m)!}{(n + m)!} {[P_{n}^{m} (cos β)]}^{2} (1 - {| s_{n} |}^{2}) .

(15)

Q_{ext, sca} = σ_{ext, sca} / (π a^{2}) = \frac{4}{{(k a)}^{2}} \sum_{n = | m |}^{\infty} (2 n + 1) \frac{(n - m)!}{(n + m)!} {[P_{n}^{m} (cos β)]}^{2} {sin}^{2} (δ_{n}) .

(17)These equations were correctly given in our earlier paper []; they are equations (16)–(18) in []. Note also that cosβ is sometimes denoted by b. All the other equations and analysis in [] were correct and are unaffected by this correction. 相似文献

Photon efficient orientation estimation using polarization modulation in single-molecule localization microscopy

Rasmus . Thorsen Christiaan N. Hulleman Bernd Rieger Sjoerd Stallinga 《Biomedical optics express》2022,13(5):2835

Combining orientation estimation with localization microscopy opens up the possibility to analyze the underlying orientation of biomolecules on the nanometer scale. Inspired by the recent improvement of the localization precision by shifting excitation patterns (MINFLUX, SIMFLUX), we have adapted the idea towards the modulation of excitation polarization to enhance the orientation precision. For this modality two modes are analyzed: i) normally incident excitation with three polarization steps to retrieve the in-plane angle of emitters and ii) obliquely incident excitation with p-polarization with five different azimuthal angles of incidence to retrieve the full orientation. Firstly, we present a theoretical study of the lower precision limit with a Cramér-Rao bound for these modes. For the oblique incidence mode we find a favorable isotropic orientation precision for all molecular orientations if the polar angle of incidence is equal to

\arccos \sqrt{2 / 3} \approx 35

degrees. Secondly, a simulation study is performed to assess the performance for low signal-to-background ratios and how inaccurate illumination polarization angles affect the outcome. We show that a precision, at the Cramér-Rao bound (CRB) limit, of just 2.4 and 1.6 degrees in the azimuthal and polar angles can be achieved with only 1000 detected signal photons and 10 background photons per pixel (about twice better than reported earlier). Lastly, the alignment and calibration of an optical microscope with polarization control is described in detail. With this microscope a proof-of-principle experiment is carried out, demonstrating an experimental in-plane precision close to the CRB limit for signal photon counts ranging from 400 to 10,000. 相似文献

Broadband miniature optical ultrasound probe for high resolution vascular tissue imaging

Richard J. Colchester Edward Z. Zhang Charles A. Mosse Paul C. Beard Ioannis Papakonstantinou Adrien E. Desjardins 《Biomedical optics express》2015,6(4):1502-1511

An all-optical ultrasound probe for vascular tissue imaging was developed. Ultrasound was generated by pulsed laser illumination of a functionalized carbon nanotube composite coating on the end face of an optical fiber. Ultrasound was detected with a Fabry-Pérot (FP) cavity on the end face of an adjacent optical fiber. The probe diameter was < 0.84 mm and had an ultrasound bandwidth of ~20 MHz. The probe was translated across the tissue sample to create a virtual linear array of ultrasound transmit/receive elements. At a depth of 3.5 mm, the axial resolution was 64 µm and the lateral resolution was 88 µm, as measured with a carbon fiber target. Vascular tissues from swine were imaged ex vivo and good correspondence to histology was observed.OCIS codes: (110.5125) Photoacoustics, (110.2350) Fiber optics imaging, (060.2380) Fiber optics sources and detectors, (170.7170) Ultrasound, (170.0110) Imaging systems 相似文献

Light propagation from fluorescent probes in biological tissues by coupled time-dependent parabolic simplified spherical harmonics equations: erratum

Jorge Bouza Domínguez Yves Bérubé-Lauzière 《Biomedical optics express》2011,2(4):980

An exponent was missing in the denominator of the definition of the Henyey-Greenstein phase function. Besides, the normalization constant of the phase function was presented for the three dimensional case only. We give the correct expression in this erratum for the two- and three-dimensional cases. In addition, we correct for a forgotten scalar product operator in Eq. (15). Those corrections do not alter the results or the conclusions of the paper.OCIS codes: (170.3660) Light propagation in tissues, (170.6280) Spectroscopy, fluorescence and luminescence, (170.6920) Time-resolved imagingIn the definition of the Henyey-Greenstein phase function, Eq. (9) in [], an exponent was missing in the denominator. In addition, the normalization constant was given for the three-dimensional case only. The correct expression for the two- and three-dimensional cases is

p^{x} (r, \hat{s}, \hat{s}'') = \frac{1 - {(g^{x} (r))}^{2}}{P π {[1 + {(g^{x} (r))}^{2} - 2 (g^{x} (r)) (\hat{s} \cdot \hat{s}'')]}^{γ}},

(9)where g^x(r) (the anisotropy parameter) describes the degree of anisotropy of the scattering, P is a normalization constant equal to 2 or 4 for the two- and three-dimensional cases, respectively. The exponent γ, appearing in the denominator, also depend on the dimensions of the physical domain and is equal to 1 or 3/2 for the two- and the three-dimension cases, respectively.In Eq. (15) of [] a scalar product operator is missing after the first nabla operator: the correct expression is

{(D^{x})}_{i, i} = - \nabla \cdot [\frac{1}{(4 i - 1) μ_{2 i - 1}} \nabla], i = 1 \dots l_{N} .

(15)The rest of the text remains the same as in the original paper. We checked; these were typographical errors, and do not alter the calculations nor the conclusions of the paper. 相似文献

Laser acupuncture for claudication symptoms in peripheral artery disease — Does it work? A randomized trial

Ahmad Mahdi Ahmad Hasnaa Ahmed Abdel-Aziz 《Hong Kong Physiotherapy Journal》2022,42(1):31

Background:Peripheral artery disease (PAD) receives little attention despite its clinical consequences. Intermittent claudication is the most disturbing symptom of the disease resulting in marked limitations to functional walking performance. Treadmill walking exercise is the first-line non-pharmacological treatment in PAD; however, older patients may be unable to exercise because of the functional disability of the disease itself or deconditioning.Objective:In an attempt to seek an alternative intervention, this study aimed to assess the effect of laser acupuncture on patient-reported claudication symptoms and walk performance in PAD.Methods:Thirty male patients with PAD were assigned randomly to a control group (

n_{1} = 15

64.5 \pm 3.5

years old,

25.9 \pm 2.6

kg/m²) or a study group (

n_{2} = 15

65.6 \pm 3.3

years old,

25.44 \pm 3.1

kg/m²). Inclusion criteria were mild-to-moderate PAD, Fontaine stage II, unilateral or bilateral claudications, and older men. Exclusion criteria were asymptomatic PAD, resting pain, severe or critical limb ischemia, ischemic ulcers, and patients contraindicated for laser therapy. Both groups received pharmacological treatment, but only the study group received gallium aluminum arsenide (GaAlAs) laser therapy at nine acupuncture points, namely, Liver 2 (LV2), Stomach 41 (ST41), Urinary bladder 40 (UB40), UB60, UB61, Gall bladder 30 (GB30), GB34, GB38, and GB40 for 2 days/week and five consecutive weeks. A pen-type laser device was used at a wavelength of

654.7 \pm 2

nm, with a power output of

41 \pm 3.65

mW, a spot size of 0.08 cm², and an energy density of 2 J/cm², for 60 s/point. The Edinburgh Claudication Questionnaire (ECQ) and the 6-min walk distance (6-MWD) were the endpoints of the study. The McNemar–Bowker Test and Generalized Estimating Equations Ordinal Logistic Regression Model were used for the within- and between-group statistical analyses of the categorical data of ECQ, respectively; and a mixed model MANOVA was used for the within- and between-group analyses of the 6-MWD data.Results:There was a significant improvement in patients’ response to ECQ only in the study group compared to the baseline (

p = 0.002

) and the controls (

p < 0.001

) after the intervention. The 6-MWD increased significantly in the study group compared to the baseline (

318 \pm 77

m versus

214 \pm 60

p < 0.001

).Conclusion:The GaAlAs laser acupuncture applied at selected acupoints may be a promising intervention complementary to drug therapy that could help relieve claudication symptoms and improve physical functional performance in older men with PAD (Fontaine stage II). Trials were conducted under the Trial Registration No. PACTR201912698539774. 相似文献

Ultrasound modulation of coherent light in a multiple-scattering medium: experimental verification of nonzero average phase carried by light

Mayanglambam Suheshkumar Singh Rajan Kanhirodan Ram Mohan Vasu Debasish Roy 《Biomedical optics express》2012,3(9):2100-2110

We demonstrate the phase fluctuation introduced by oscillation of scattering centers in the focal volume of an ultrasound transducer in an optical tomography experiment has a nonzero mean. The conditions to be met for the above are: (i) the frequency of the ultrasound should be in the vicinity of the most dominant natural frequency of vibration of the ultrasound focal volume, (ii) the corresponding acoustic wavelength should be much larger than

ℓ_{n}^{*}

, a modified transport mean-free-path applicable for phase decorrelation and (iii) the focal volume of the ultrasound transducer should not be larger than 4 – 5 times

{(ℓ_{n}^{*})}^{3}

. We demonstrate through simulations that as the ratio of the ultrasound focal volume to

{(ℓ_{n}^{*})}^{3}

increases, the average of the phase fluctuation decreases and becomes zero when the focal volume becomes greater than around

4 {(ℓ_{n}^{*})}^{3}

; and through simulations and experiments that as the acoustic frequency increases from 100 Hz to 1 MHz, the average phase decreases to zero. Through experiments done in chicken breast we show that the average phase increases from around 110° to 130° when the background medium is changed from water to glycerol, indicating that the average of the phase fluctuation can be used to sense changes in refractive index deep within tissue.OCIS codes: (170.0170) Medical optics and biotechnology, (170.3880) Medical and biological imaging, (110.0110) Imaging systems, (110.6150) Speckle imaging, (110.7170) Ultrasound 相似文献

Immediate effects of manual hyperinflation on cardiorespiratory function and sputum clearance in mechanically ventilated pediatric patients: A randomized crossover trial

Tawatchai Luadsri Jaturon Boonpitak Kultida Pongdech-Udom Patnuch Sukpom Weerapong Chidnok 《Hong Kong Physiotherapy Journal》2022,42(1):15

Background:In developing countries, lower respiratory tract infection is a major cause of death in children, with severely ill patients being admitted to the critical-care unit. While physical therapists commonly use the manual hyperinflation (MHI) technique for secretion mass clearance in critical-care patients, its efficacy has not been determined in pediatric patients.Objective:This study investigated the effects of MHI on secretion mass clearance and cardiorespiratory responses in pediatric patients undergoing mechanical ventilation.Methods:A total of 12 intubated and mechanically ventilated pediatric patients were included in this study. At the same time of the day, the patients received two randomly ordered physical therapy treatments (MHI with suction and suction alone) from a trained physical therapist, with a washout period of 4 h provided between interventions.Results:The MHI treatment increased the tidal volume [

V_{t}

; 1.2 mL/kg (95% CI, 0.8–1.5)] and static lung compliance [

C_{stat}

; 3.7 mL/cmH₂O (95% CI, 2.6–4.8)] immediately post-intervention compared with the baseline (

p < 0.05

). Moreover, the MHI with suction induced higher

V_{t}

[1.4 mL/kg (95% CI, 0.8–2.1)] and

C_{stat}

[3.4 mL/cmH₂O (95% CI, 2.1–4.7)] compared with the suction-alone intervention. In addition, the secretion mass [0.7 g (95% CI, 0.6–0.8)] was greater in MHI with suction compared with suction alone (

p < 0.05

). However, there was no difference in peak inspiratory pressure, mean airway pressure, respiratory rate, heart rate, blood pressure, mean arterial blood pressure or oxygen saturation (

p > 0.05

) between interventions.Conclusions:MHI can improve

V_{t}

C_{stat}

and secretion mass without inducing adverse hemodynamic effects upon the pediatric patients requiring mechanical ventilation. 相似文献

10.

Measurement of the reduced scattering coefficient of turbid media using single fiber reflectance spectroscopy: fiber diameter and phase function dependence

Kanick SC Gamm UA Schouten M Sterenborg HJ Robinson DJ Amelink A 《Biomedical optics express》2011,2(6):1687-1702

This paper presents a relationship between the intensity collected by a single fiber reflectance device (R_SF) and the fiber diameter (d_fib) and the reduced scattering coefficient (

μ_{s}^{'}

) and phase function (p(θ)) of a turbid medium. Monte Carlo simulations are used to identify and model a relationship between R_SF and dimensionless scattering (

μ_{s}^{'} d_{fib}

). For

μ_{s}^{'} d_{fib} > 10

we find that R_SF is insensitive to p(θ). A solid optical phantom is constructed with

μ_{s}^{'} \approx 220 {mm}^{- 1}

and is used to convert R_SF of any turbid medium to an absolute scale. This calibrated technique provides accurate estimates of

μ_{s}^{'}

over a wide range ([0.05 – 8] mm⁻¹) for a range of d_fib ([0.2 – 1] mm).OCIS codes: (300.6550) Spectroscopy, visible; (280.1350) Backscattering; (060.2310) Fiber optics; (290.7050) Turbid media; (170.3660) Light propagation in tissues 相似文献

11.

Heart rate variability,exercise capacity and levels of daily physical activity in children and adolescents with mild-to-moderate cystic fibrosis

Pitiguara de Freitas Coelho Roberta Ribeiro Batista Barbosa Rodrigo dos Santos Lugao Fernanda Mayrink Gonalves Liberato Pmela Reis Vidal Roberta de Cssia Nunes Cruz Melotti Mrcio Vinícius Fagundes Donadio 《Hong Kong Physiotherapy Journal》2022,42(1):5

Background:Autonomic nervous system balance is altered in cystic fibrosis (CF), although its influence on physical fitness has been poorly explored.Objective:This study aimed to evaluate the association of heart rate variability (HRV) with exercise capacity and levels of daily physical activity in children and adolescents with mild-to-moderate CF.Methods:A cross-sectional study including individuals with CF aged 6–18 years, not under CFTR modulator therapy, was performed. Sociodemographic (age, sex) and clinical information (airway colonization, pancreatic insufficiency, and genotyping) were collected. In addition, exercise capacity (modified shuttle test — MST), lung function (spirometry), body composition (bioimpedance), levels of daily physical activity (5-day accelerometer), and HRV (both at rest and during the MST) were evaluated.Results:30 individuals (20 females) aged

11.2 \pm 3.7

years, mean FEV

_{1} 62.8 \pm 27.6

%, were included. A sympathovagal balance (LF/HF) increase (

p < 0.001

) during the MST was shown, indicating a predominance of sympathetic modulation. The standard deviation of all RR intervals (SDNN) and the high frequency (HF) index during exercise correlated significantly with FEV₁ (

r = 0.45

p = 0.01

and

r = 0.46

p = 0.01

; respectively). MST distance also correlated positively and significantly with SDNN (

r = 0.43

p = 0.01

), square root of the mean of the sums of squares of frequencies between RR intervals greater than 50 ms — RMSSD (

r = 0.53

p < 0.01

), low frequency — LF (

r = 0.48

p < 0.01

), HF (

r = 0.64

p < 0.01

), dispersion of points perpendicular to the short-term identity line — SD1 (

r = 0.40

p = 0.02

) and negatively with LF/HF (

r =- 0.57

p < 0.01

). Regarding daily physical activity, SDNN at rest (

r = 0.37

p = 0.04

) and exercise (

r = 0.41

p = 0.02

) showed positive correlations with time in moderate-to-vigorous activities. When normalizing the SDNN and classifying individuals as normal or altered, those presenting altered SDNN showed poorest FEV₁ (

p = 0.001

) and lower exercise capacity (

p = 0.027

).Conclusion:HRV correlates with lung function, exercise capacity and levels of daily physical activity in children and adolescents with CF. The study highlights the influence of CF on autonomic function and suggests HRV measurement as an easy tool to be used in clinical settings as an alternative marker to monitor CF individuals. 相似文献

12.

Learning-based prediction of gestational age from ultrasound images of the fetal brain

《Medical image analysis》2015,22(1):72-86

相似文献

13.

Acetazolamide and midazolam act synergistically to inhibit neuropathic pain

Marina Asiedu Michael H. Ossipov Kai Kaila Theodore J. Price 《Pain》2010

相似文献

14.

Analysis of ventilatory ratio as a novel method to monitor ventilatory adequacy at the bedside

Pratik Sinha Nicholas J Fauvel Pradeep Singh Neil Soni 《Critical care (London, England)》2013,17(1):R34

Introduction

Due to complexities in its measurement, adequacy of ventilation is seldom used to categorize disease severity and guide ventilatory strategies. Ventilatory ratio (VR) is a novel index to monitor ventilatory adequacy at the bedside.

VR = ({\dot{V}}_{E m e a s u r e d} \times P a_{C O_{2 m e a s u r e d}}) / ({\dot{V}}_{E p r e d i c t e d} \times P a_{C O_{2 i d e a l}})

{\dot{V}}_{E p r e d i c t e d}

is 100 mL.Kg^-1.min^-1and Pa_{CO_{2 ideal}} is 5 kPa. Physiological analysis shows that VR is influenced by dead space (V_D/V_T) and CO2 production

(\dot{V} C O_{2})

. Two studies were conducted to explore the physiological properties of VR and assess its use in clinical practice.

Methods

Both studies were conducted in adult mechanically ventilated ICU patients. In Study 1, volumetric capnography was used to estimate daily V_D/V_Tand measure

\dot{V} C O_{2}

in 48 patients. Simultaneously, ventilatory ratio was calculated using arterial blood gas measurements alongside respiratory and ventilatory variables. This data was used to explore the physiological properties of VR. In Study 2, 224 ventilated patients had daily VR and other respiratory variables, baseline characteristics, and outcome recorded. The database was used to examine the prognostic value of VR.

Results

Study 1 showed that there was significant positive correlation between VR and VD/VT (modified r = 0.71) and

\dot{V} C O_{2}

(r = 0.14). The correlation between VR and V_D/V_Twas stronger in mandatory ventilation compared to spontaneous ventilation. Linear regression analysis showed that V_D/V_Thad a greater influence on VR than

\dot{V} C O_{2}

(standardized regression coefficient 1/1-V_D/V_T: 0.78,

\dot{V} C O_{2}

: 0.44). Study 2 showed that VR was significantly higher in non-survivors compared to survivors (1.55 vs. 1.32; P < 0.01). Univariate logistic regression showed that higher VR was associated with mortality (OR 2.3, P < 0.01), this remained the case after adjusting for confounding variables (OR 2.34, P = 0.04).

Conclusions

VR is an easy to calculate bedside index of ventilatory adequacy and appears to yield clinically useful information. 相似文献

15.

The concept of precision extended to the atherogenic index of plasma

Holmes DT Frohlich J Buhr KA 《Clinical biochemistry》2008,41(7-8):631-635

相似文献

16.

Unraveling the effect of Al doping on CO adsorption at ZnO(101̄0)

D. C. Nguyen Thanh Khoa Phung Dai-Viet N. Vo Tu Hai Le Dinh Quang Khieu Thong Le Minh Pham 《RSC advances》2020,10(67):40663

Understanding the effect of Al doping on CO adsorption at ZnO(10

\bar{1}

0) is crucial for designing a high-performance CO gas sensor. In this work, we investigated the adsorption properties of CO on pristine and Al-doped ZnO(10

\bar{1}

0) by performing DFT+U calculations. It is found that the doping of Al on ZnO(10

\bar{1}

0) induces the semiconductor-to-metal transition and thus enhances the conductance of the substrate. Compared to the pristine ZnO(10

\bar{1}

0), the adsorption energy of CO on the Al-doped surfaces is significantly enhanced since Al doping has the effect of strengthening the adsorption bond. The bonding analysis reveals that CO adsorbs on pristine ZnO(10

\bar{1}

0) via the sole σ-dative donation between the CO HOMO 5σ and the empty states of the Zn cation while π-back donation from filled states of Zn or Al cations to the CO 2π* LUMO is facilitated on the Al-doped surfaces. The π-back donation also results in the red-shift of the CO stretching frequency on the Al-doped surfaces, contrasting to the blue-shift on the pristine surface. The simulated results demonstrate that the doping of Al to a three-fold coordinated site on ZnO(10

\bar{1}

0) is highly beneficial for boosting the performance of the CO gas sensor. Our theoretical investigation provides fundamental insights into the effect of Al doping on the sensing mechanism for CO at the ZnO(10

\bar{1}

0) surface.

Al doping enhances the adsorption of CO on ZnO(10

\bar{1}

0) by facilitating π-back donation from the surface to CO. 相似文献

17.

Asymmetric distribution of pathogenic low wall shear stress of the bilateral subclavian arteries: two case reports

Huai Wu Yuan Jin Xun Yao Si Yu Huang Min Yong Cui Ren Jie Ji Jia Rui Li Li Hua Chen 《The Journal of international medical research》2021,49(9)

The effects of increasing blood flow on the pathogenic wall shear stress (pWSS) of subclavian arteries (SAs) are currently unclear. Patient-specific models of the SA were constructed based on computed tomographic images from two patients. Using the Ansys Fluent 19.0 transient laminar flow solver, the finite volume method was chosen to solve the Navier–Stokes equation governing fluid behavior. The time-averaged wall shear stress, ratio of risk area, cumulative ratio of risk area (

\bar{P}

), ratio of risk time, and ratio contour of risk time were calculated to describe the temporal and spatial distributions of pWSS. Virtually all pWSS occurred during the diastolic phase. The

\bar{P}

was 2.3 and 1.29 times higher on the left than on the right in Patients 1 (P1) and 2 (P2), respectively. Increasing the blood flow volume of the left SA by 20%, 40%, and 60% led to a 9.27%, 15.10%, and 20.99% decrease in

\bar{P}

for P1 and a 5.74%, 11.55%, and 17.14% decrease in

\bar{P}

for P2, respectively, compared with baseline values. In conclusion, the left SA showed greater diastolic pWSS than the right SA, and increasing the blood flow volume reduced the pWSS in the left SA. 相似文献

18.

Dual optimization based prostate zonal segmentation in 3D MR images

《Medical image analysis》2014,18(4):660-673

相似文献

19.

Hexagonal VO2 particles: synthesis,mechanism and thermochromic properties

Hui Yan Xu Ke Wei Xu Fei Ma Paul K. Chu 《RSC advances》2018,8(18):10064

Monoclinic vanadium dioxide VO₂ (M) with hexagonal structure is synthesized by hydrothermal method, and the phase evolution is evidenced. Interestingly, the hexagonal morphology comes into being as a result of the low-energy coherent interfaces, (21

\bar{1}

)₁//(2

\bar{1}

\bar{1}

)₂ and (2

\bar{1}

\bar{1}

)₁//(020)₂. The size of hexagonal particles is well controlled by changing the concentration of precursor solutions. Hexagonal particles exhibit excellent thermochromic properties with a narrow hysteresis of 5.9 °C and high stability. In addition, the phase transition temperature can be substantially reduced down to 28 °C by simply W doping.

Monoclinic vanadium dioxide VO₂ (M) with hexagonal structure is synthesized by hydrothermal method, and the phase evolution is evidenced. 相似文献

20.

Comparative effects of tensioning and sliding neural mobilization on peripheral and autonomic nervous system function: A randomized controlled trial

Budour Yousif Alharmoodi Ashokan Arumugam Amal Ahbouch Ibrahim M. Moustafa 《Hong Kong Physiotherapy Journal》2022,42(1):41

Background:Although different types of neural mobilization (NM) exercises induce different amounts of longitudinal nerve excursion and strain, the question whether the increased longitudinal stress and nerve excursion from sliding or tensioning intervention may subtly affect the neural functions has not been answered yet.Objective:To compare the effects of tensioning NM versus sliding NM of the median nerve on peripheral and autonomic nervous system function.Methods:In this randomized controlled trial, 90 participants were randomly assigned to tensioning NM, sliding NM, or sham NM. The neurophysiological outcome measures included peak-to-peak amplitude of the dermatomal somatosensory evoked potential (DSSEP) for dermatomes C6, C7, C8, and T1. Secondary outcome measures included amplitude and latency of skin sympathetic response. All outcome measures were assessed pretreatment, immediately after the two weeks of treatment and one week after the last session of the treatment.Results:A 2-way repeated measures ANOVA revealed significant differences between the three groups. The post hoc analysis indicated that tensioning NM significantly decreased the dermatomal amplitude for C6, C7, C8, and T1 (

p < 0.005

). Sympathetic skin responses in the gliding NM group showed lower amplitudes and prolonged latencies post-treatment when compared to tensioning NM group (

p < 0.05

). In contrast, no significant changes were observed in the DSSEPs and skin sympathetic responses for participants in the sham treatment group (

p > 0.05

).Conclusions:A tensioning NM on the median nerve had a possible adverse effect on the neurophysiology variables of the nerves involved in the neural mobilization. Thus, tensioning NM with the current parameters that place increased stress and strain on the peripheral nervous system should be avoided. 相似文献