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3.
Surg Endosc ; 37(3): 1629-1648, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36781468

RESUMO

BACKGROUND: In recent years, the use of Indocyanine Green (ICG) fluorescence-guided surgery during open and laparoscopic procedures has exponentially expanded across various clinical settings. The European Association of Endoscopic Surgery (EAES) initiated a consensus development conference on this topic with the aim of creating evidence-based statements and recommendations for the surgical community. METHODS: An expert panel of surgeons has been selected and invited to participate to this project. Systematic reviews of the PubMed, Embase and Cochrane libraries were performed to identify evidence on potential benefits of ICG fluorescence-guided surgery on clinical practice and patient outcomes. Statements and recommendations were prepared and unanimously agreed by the panel; they were then submitted to all EAES members through a two-rounds online survey and results presented at the EAES annual congress, Barcelona, November 2021. RESULTS: A total of 18,273 abstracts were screened with 117 articles included. 22 statements and 16 recommendations were generated and approved. In some areas, such as the use of ICG fluorescence-guided surgery during laparoscopic cholecystectomy, the perfusion assessment in colorectal surgery and the search for the sentinel lymph nodes in gynaecological malignancies, the large number of evidences in literature has allowed us to strongly recommend the use of ICG for a better anatomical definition and a reduction in post-operative complications. CONCLUSIONS: Overall, from the systematic literature review performed by the experts panel and the survey extended to all EAES members, ICG fluorescence-guided surgery could be considered a safe and effective technology. Future robust clinical research is required to specifically validate multiple organ-specific applications and the potential benefits of this technique on clinical outcomes.


Assuntos
Colecistectomia Laparoscópica , Laparoscopia , Humanos , Verde de Indocianina , Consenso , Fluorescência , Laparoscopia/métodos
5.
Opt Express ; 29(19): 30675-30681, 2021 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-34614788

RESUMO

We present a C-band 6-mode 7-core fiber amplifier in an all-fiberized cladding-pumped configuration for space division multiplexed transmission supporting a record 42 spatial channels. With optimized fiber components (e.g. passively cooled pump laser diode, pump coupler, pump stripper), high power multimode pump light is coupled to the active fiber without any noticeable thermal degradation and an average gain of 18 dB and noise figure of 5.4 dB are obtained with an average differential modal gain of 3.4 dB.

6.
Phys Med Biol ; 66(6): 064006, 2021 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-33636710

RESUMO

Achieving direct imaging of the annihilation position of a positron on an event-by-event basis using an ultrafast detector would have a great impact on the field of nuclear medicine. Cherenkov emission is the most attractive physical phenomenon for realizing such an ultrafast timing performance. Moreover, a microchannel-plate photomultiplier tube (MCP-PMT) is one of the most promising photodetectors for fully exploiting the fast timing properties of Cherenkov emission owing to its excellent single photon time resolution of 25 ps full width at half maximum (FWHM). However, as the MCP structure generally contains a lead compound, the gamma rays frequently and directly interact with the MCP, resulting in the degradation of its timing performance and generation of undesirable side peaks in its coincidence timing histogram. To overcome this problem, we have developed a new MCP-PMT based on an MCP consisting of borosilicate glass, thus drastically reducing the probability of the photoelectric effect occurring in the MCP. To evaluate its insensitivity to gamma rays and its timing performance, a coincidence experiment was performed and showed that the probability of direct interactions was reduced by a factor of 3.4. Moreover, a coincidence time resolution of 35.4 ± 0.4 ps FWHM, which is equivalent to a position resolution of 5.31 mm, was obtained without any pulse height/area cut, improving to 28.7 ± 3.0 ps when selecting on the highest amplitude events by careful optimization of the voltage divider circuit of the new MCP-PMT. The timing performance of this new MCP-PMT presents an important step toward making direct imaging possible.


Assuntos
Chumbo , Tomografia por Emissão de Pósitrons/métodos , Dióxido de Silício/química , Eletrodos , Desenho de Equipamento , Raios gama , Vidro , Háfnio/química , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Teste de Materiais , Distribuição Normal , Oscilometria , Óxidos/química , Fótons , Fenômenos Físicos , Probabilidade , Razão Sinal-Ruído , Isótopos de Sódio
7.
8.
Eur Heart J Cardiovasc Imaging ; 22(1): 49-57, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32259839

RESUMO

AIMS: Cardiac resynchronization therapy (CRT) is a disease-modifying therapy in patients with chronic heart failure (CHF). Current guidelines ascribe CRT eligibility on three parameters only: left ventricular ejection fraction (LVEF), QRS duration, and New York Heart Association (NYHA) functional class. However, one-third of CHF patients does not benefit from CRT. This study evaluated whether 123I-meta-iodobenzylguanidine (123I-mIBG) assessed cardiac sympathetic activity could optimize CRT patient selection. METHODS AND RESULTS: A total of 78 stable CHF subjects (age 66.8 ± 9.6 years, 73% male, LVEF 25.2 ± 6.7%, QRS duration 153 ± 23 ms, NYHA 2.2 ± 0.7) referred for CRT implantation were enrolled. Subjects underwent 123I-mIBG scintigraphy prior to implantation. Early and late heart-to-mediastinum (H/M) ratio and 123I-mIBG washout were calculated. CRT response was defined as either an increase of LVEF to >35%, any improvement in LVEF of >10%, QRS shortening to <150 ms, or improvement in NYHA class of >1 class. In 33 patients LVEF increased to >35%, QRS decreased <150 ms in 36 patients, and NYHA class decreased in 33 patients. Late H/M ratio and hypertension were independent predictors of LVEF improvement to >35% (P = 0.0014 and P = 0.0149, respectively). In addition, early H/M ratio, LVEF, and absence of diabetes mellitus (DM) were independent predictors for LVEF improvement by >10%. No independent predictors were found for QRS shortening to <150 ms or improvement in NYHA class. CONCLUSION: Early and late H/M ratio were independent predictors of CRT response when improvement of LVEF was used as measure of response. Therefore, cardiac 123I-mIBG scintigraphy may be used as a tool to optimize selection of subjects that might benefit from CRT.


Assuntos
Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca , 3-Iodobenzilguanidina , Idoso , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/terapia , Humanos , Radioisótopos do Iodo , Masculino , Pessoa de Meia-Idade , Cintilografia , Compostos Radiofarmacêuticos , Volume Sistólico , Função Ventricular Esquerda
9.
Sci Adv ; 6(25): eaaz9744, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32596450

RESUMO

Nanometer-scale skyrmions are prospective candidates for information bits in low-power consumption devices owing to their topological nature and controllability with low current density. Studies on skyrmion dynamics in different classes of materials have exploited the topological Hall effect and current-driven fast motion of skyrmionic bubbles. However, the small current track motion of a single skyrmion and few-skyrmion aggregates remains elusive. Here, we report the tracking of creation and extinction and motion of 80-nm-size skyrmions upon directional one-current pulse excitations at low current density of the order of 109 A m-2 in designed devices with the notched hole. The Hall motion of a single skyrmion and the torque motions of few-skyrmion aggregates have been directly revealed. The results exemplify low-current density controls of skyrmions, which will pave the way for the application of skyrmions.

10.
Mol Biol Cell ; 31(15): 1595-1610, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-32432944

RESUMO

Tractional remodeling of collagen fibrils by fibroblasts requires long cell extensions that mediate fibril alignment. The formation of these cell extensions involves flightless I (FliI), an actin-binding protein that contains a leucine-rich-repeat (LRR), which binds R-ras and may regulate cdc42. We considered that FliI interacts with small GTPases and their regulators to mediate assembly of cell extensions. Mass spectrometry analyses of FliI immunoprecipitates showed abundant Ras GTPase-activating-like protein (IQGAP1), which in immunostained samples colocalized with FliI at cell adhesions. Knockdown of IQGAP1 reduced the numbers of cell extensions and the alignment of collagen fibrils. In experiments using dominant negative mutants, cdc42 activity was required for the formation of short extensions while R-ras was required for the formation of long extensions. Immunoprecipitation of wild-type and mutant constructs showed that IQGAP1 associated with cdc42 and R-ras; this association required the GAP-related domain (1004-1237 aa) of IQGAP1. In cells transfected with FliI mutants, the LRR of FliI, but not its gelsolin-like domains, mediated association with cdc42, R-ras, and IQGAP1. We conclude that FliI interacts with IQGAP1 and co-ordinates with cdc42 and R-ras to control the formation of cell extensions that enable collagen tractional remodeling.


Assuntos
Extensões da Superfície Celular/metabolismo , Matriz Extracelular/metabolismo , Proteínas dos Microfilamentos/metabolismo , Transativadores/metabolismo , Proteínas Ativadoras de ras GTPase/metabolismo , Proteínas ras/metabolismo , Células 3T3 , Animais , Adesão Celular , Colágeno/farmacologia , Camundongos , Modelos Biológicos , Ligação Proteica/efeitos dos fármacos , Domínios Proteicos , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas Ativadoras de ras GTPase/química
11.
Phys Rev Lett ; 124(19): 193201, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32469563

RESUMO

Ultrafast multiphoton ionization of Xe in strong extreme ultraviolet free-electron laser (FEL) fields (91 eV, 30 fs, 1.6×10^{12} W/cm^{2}) has been investigated by multielectron-ion coincidence spectroscopy. The electron spectra recorded in coincidence with Xe^{4+} show characteristic features associated with two-photon absorption to the 4d^{-2} double core-hole (DCH) states and subsequent Auger decay. It is found that the pathway via the DCH states, which has eluded clear identification in previous studies, makes a large contribution to the multiple ionization, despite the long FEL pulse duration compared with the lifetime of the 4d core-hole states.

12.
Phys Med Biol ; 65(10): 10NT03, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32325434

RESUMO

In order to achieve the ultimate goal of reducing coincidence time resolution (CTR) to 10 ps, thus enabling reconstruction-less positron emission tomography, a Cherenkov-radiator-integrated microchannel plate photomultiplier tube (CRI) reaching CTR of sub-50 ps full width at half maximum (FWHM) has been developed. However, a histogram of time differences between a pair of the CRIs shows undesirable side peaks, which are caused by gamma rays directly interacting with the micro channel plates (MCPs). Such direct interaction events are detrimental to the timing performance of the CRI. In this paper, we demonstrate an analytical method of deconvolving MCP direct interaction events from the timing histogram. Considering the information of the main and the two side peaks, the timing uncertainty caused by the MCP direct interaction events is deconvolved and the CTR of the CRI is analytically investigated. Consequently, the CTR is improved from 41.7 to 40.5 ps FWHM by the deconvolution. It means that a mixture of the Cherenkov radiator events and the MCP direct interaction events contribute to the CTR by a factor of 10 ps. The timing performance of the MCP direct interaction events are also evaluated. The CTR between the two MCPs is found to be 66.2 ps FWHM. This indicates that a photocathode-free radiation detector with high timing performance is possible. Elimination of the photocathode from the detector would make detector construction easier and more robust.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Tomografia por Emissão de Pósitrons , Artefatos , Radiometria , Contagem de Cintilação , Razão Sinal-Ruído , Fatores de Tempo
13.
Adv Exp Med Biol ; 1232: 113-119, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31893402

RESUMO

The prefrontal cortex (PFC) is sensitive to the stress exposure and involved in stress coping. And the effects of gum chewing on the stress have been studied using NIRS. However, when measuring NIRS on PFC during gum chewing, blood flows in shallow tissues (scalp, skin, muscle) might be affected. A NIRS used in the present study first, which has a short distance (1 cm) and the usual (3 cm) source-detector (S-D) regression, can allow eliminating shallow tissues effect of gum chewing. The aim of this study was to investigate the hypothesis that gum chewing activates the right prefrontal cortex (PFC) in stress coping against negative sounds (NS) from the International Affective Digitized Sounds-2 (IADS) as a mental stress task. NS showed activation in the right PFC. There was a significant difference between NS, and NS with Gum, where NS with Gum showed an increased PFC activity, increased alpha wave appearance rate, a higher value in heart rate level, and a higher VAS score indicating 'pleasant'. Gum chewing activated right PFC activity while exposed to negative sounds from IADS as a mental stress task.


Assuntos
Goma de Mascar , Mastigação , Som , Estresse Psicológico , Adaptação Psicológica , Adulto , Feminino , Humanos , Masculino , Córtex Pré-Frontal/fisiologia , Córtex Pré-Frontal/efeitos da radiação , Som/efeitos adversos , Estresse Psicológico/terapia , Adulto Jovem
14.
Osteoporos Int ; 31(4): 757-763, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31814062

RESUMO

We compared the bone strength measured via quantitative computed tomography-based finite element method (QCT/FEM) between healthy adults with and without ossification of the posterior longitudinal ligament (OPLL). No statistically significant difference was observed in the bone strength between healthy adults with and without OPLL. Hyperostosis of the posterior longitudinal ligament in OPLL may not be associated with the systemic bone strength. INTRODUCTION: Although patients with OPLL have been reportedly associated with increased level of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA), little is known about the bone strength in OPLL subjects. The aim of this study is to investigate the bone strength measured via QCT/FEM in healthy subjects with OPLL using the medical check-up data, including whole-body CT scans. METHODS: We examined 796 participants (529 men and 267 women) who underwent CT scans in a single health center between January 2008 and May 2009. We identified OPLL in whole spine and divided the subjects into two groups: non-OPLL and OPLL groups. We calculated the predicted bone strength (PBS) of the proximal femur using QCT/FEM and examined the bone mineral status of the calcaneus using quantitative ultrasound (QUS). We compared the PBS and the QUS parameters between the non-OPLL and OPLL groups. RESULTS: Seventy-four subjects (9.3%; 57 men and 17 women) were diagnosed with OPLL in the whole spine. The OPLL group was significantly older than the non-OPLL group. No statistically significant difference was observed in the PBS and the QUS parameters between the non-OPLL and OPLL groups in both sexes. Furthermore, no statistically significant difference was noted in the PBS and the QUS parameters between two groups in age- and gender-matched analysis. CONCLUSIONS: Our results suggest that hyperostosis of the posterior longitudinal ligament in OPLL may not be associated with bone strength and bone mineral status at the extremities.


Assuntos
Fêmur/fisiologia , Ossificação do Ligamento Longitudinal Posterior , Absorciometria de Fóton , Adulto , Densidade Óssea , Feminino , Fêmur/diagnóstico por imagem , Voluntários Saudáveis , Humanos , Ligamentos Longitudinais/diagnóstico por imagem , Masculino , Ossificação do Ligamento Longitudinal Posterior/diagnóstico por imagem , Osteogênese
15.
J Comp Pathol ; 173: 30-40, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31812171

RESUMO

The aim of this study was to investigate the expression of tumour endothelial marker 8 (TEM8) in canine mammary gland tumours (MGTs) by immunohistochemistry and to evaluate the association between tumour cell TEM8 expression and tumour histological features, histological grades and expression of luminal and basal/myoepithelial cell markers. TEM8 expression was detected in >60 % of neoplastic epithelial cells in all simple adenomas (n = 25), simple carcinomas (n = 43) and invasive micropapillary carcinomas (n = 5) studied. Six of the 18 solid carcinomas studied showed TEM8 expression in >60% of carcinoma cells present in solid structures and in 12 of the 18 solid carcinomas, <30% of the luminal structure-forming carcinoma cells showed TEM8 expression. TEM8 expression in the neoplastic cells was not associated with histological malignancy in canine MGTs. TEM8+ tumour cells frequently showed the luminal-like phenotype cytokeratin (CK)19+/p63-/α-smooth muscle actin (SMA)-, while most TEM8- tumour cells exhibited the basal-like phenotype CK19-/p63+/αSMA-. These findings indicate that TEM8 may be involved in maintaining the characteristics of luminal cells in canine MGTs and that TEM8 would be useful in identifying the type of neoplastic epithelial cell in MGTs.


Assuntos
Adenocarcinoma/veterinária , Adenoma/veterinária , Doenças do Cão/patologia , Neoplasias Mamárias Animais/patologia , Receptores de Peptídeos/biossíntese , Animais , Biomarcadores Tumorais/análise , Doenças do Cão/metabolismo , Cães , Feminino , Neoplasias Mamárias Animais/metabolismo , Receptores de Peptídeos/análise
16.
J Opt Soc Am A Opt Image Sci Vis ; 36(12): 2129-2137, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31873389

RESUMO

To expand the spectral bandwidths with high diffraction efficiency of volume phase (VP) gratings, it is important to know the influence of a variety of refractive index distributions (RIDs) inside the recording material on the bandwidths. The influence of various graded types of RIDs on the full width at half the maximum of the spectral bandwidth (${\lambda _{\rm FWHM}}$λFWHM) and the angular bandwidth (${\theta _{\rm FWHM}}$θFWHM) is investigated in the Bragg regime. It becomes clear that various graded types of RIDs influence their bandwidths and the characteristics, and the combination of the RIDs and refractive index modulation (${{ n}_m}$nm) is the most important factor for obtaining the large bandwidths of VP gratings. Theoretically, the ${\lambda _{\rm FWHM}}$λFWHM are obtained as the values of 149.7 nm and 257.6 nm (${{ n}_m} = {0.045}$nm=0.045) for the wavelengths of 900 nm and 1550 nm, respectively. Furthermore, I have succeeded in developing the expression for ${\lambda _{\rm FWHM}}$λFWHM and ${\theta _{\rm FWHM}}$θFWHM, using the proportional characteristics of VP gratings investigated in this work. The correlative coupling-length coefficients "G-factors" devised as a variety of RID functions in the previous paper are introduced into them. It is apparent that the derived equations of the bandwidths can be adapted to any graded type of RID that changes continuously from a triangular type to a rectangular type of VP grating, which has not been reported yet. The equations have made it easy to design ${\lambda _{\rm FWHM}}$λFWHM and ${\theta _{\rm FWHM}}$θFWHM of VP gratings.

17.
J Opt Soc Am A Opt Image Sci Vis ; 36(11): 1861-1870, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31873697

RESUMO

The equations for the coupling coefficient and the grating thickness of volume phase gratings are derived from Maxwell's equations in this work. The equations cover all graded types of refractive index distributions (RIDs) which change continuously from a triangular type to a rectangular type. The functions expressed as various graded types of RIDs, which are proposed in this work, are used among them. Furthermore, the new idea, which is the correlative coupling-length coefficient, is devised for the first time as a variety of RID function, "G-factor." The results based on the coupled mode theory in this work show a very close agreement under 0.2% with the results of the rigorous coupled-wave analysis method. The values of the grating thickness and the G-factor are confirmed with validity. By means of this new method, not only can the grating thickness of any graded type of VP grating which is under the Bragg condition be obtained very easily, but the spectral bandwidths and the angular bandwidths which are not under the Bragg condition can be controlled very easily and the configurations of RIDs can be estimated as well.

18.
Phys Rev Lett ; 122(21): 217003, 2019 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-31283313

RESUMO

We report neutron scattering measurements of single-crystalline YFe_{2}Ge_{2} in the normal state, which has the same crystal structure as the 122 family of iron pnictide superconductors. YFe_{2}Ge_{2} does not exhibit long-range magnetic order but exhibits strong spin fluctuations. Like the iron pnictides, YFe_{2}Ge_{2} displays anisotropic stripe-type antiferromagnetic spin fluctuations at (π, 0, π). More interesting, however, is the observation of strong spin fluctuations at the in-plane ferromagnetic wave vector (0, 0, π). These ferromagnetic spin fluctuations are isotropic in the (H, K) plane, whose intensity exceeds that of stripe spin fluctuations. Both the ferromagnetic and stripe spin fluctuations remain gapless down to the lowest measured energies. Our results naturally explain the absence of magnetic order in YFe_{2}Ge_{2} and also imply that the ferromagnetic correlations may be a key ingredient for iron-based materials.

19.
Phys Med Biol ; 64(7): 07LT01, 2019 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-30870825

RESUMO

Radiation detectors dedicated to time-of-flight positron emission tomography (PET) have been developed, and coincidence time resolution (CTR) of sub-100 ps full width at half maximum (FWHM) has been achieved by carefully optimizing scintillators and photodetectors. Achieving a CTR of 30 ps FWHM by using a pair of annihilation γ-rays would allow us to directly localize the annihilation point within an accuracy of 4.5 mm. Such direct localization can potentially eliminate the requirement of image reconstruction processes in clinical PET systems, which would have a huge impact on clinical protocols and molecular imaging. To obtain such a high CTR, researchers have investigated the use of prompt emissions such as Cherenkov radiation and hot-intra band luminescence. Although it is still challenging to achieve a CTR of 30 ps FWHM even with a Cherenkov-based detector, the experimentally measured CTR is approaching the goal. In this work, we developed a Cherenkov-radiator-integrated micro-channel plate photomultiplier tube (CRI-MCP-PMT), where there are no optical boundaries between the radiator and photocathode, and its timing performance was investigated. By removing the optical boundaries, reflections are eliminated and transmission to the photocathode is improved, resulting in high timing capability. As a result, a CTR of 30.1 ± 2.4 ps FWHM, which is equivalent to a position resolution of 4.5 ± 0.3 mm along a line of response (LOR), was obtained by using a pair of CRI-MCP-PMTs.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Tomografia por Emissão de Pósitrons/instrumentação , Contagem de Cintilação/instrumentação , Raios gama , Humanos , Tomografia por Emissão de Pósitrons/métodos , Fatores de Tempo
20.
Opt Express ; 26(12): 15211-15220, 2018 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-30114771

RESUMO

We propose and experimentally demonstrate a low-loss and low-crosstalk Mach-Zehnder mode/wavelength multi/demultiplexer for WDM/MDM transmission based on a Si-photonics platform. A broadband 3-dB mode divider, which is also newly devised here, makes it possible to compose a Mach-Zehnder filter for "mode" and "wavelength" simultaneously. Transmission characteristics of fabricated 3-dB mode dividers are in excellent agreement with theoretical results. Mach-Zehnder filters using the 3-dB mode divider with a free spectral range (FSR) of 20 and 1 nm are also fabricated and the modal crosstalk is less than -24 dB in the 40-nm wavelength range for the MZ filter with an FSR of 20 nm. The tuning of the peak wavelength position by the TiN heater is also demonstrated.

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