A Comparison of In Vitro Measurement and Ultrasound for Peripherally Inserted Central Catheter Placement in Premature Infants: A Before-and-After Self-Controlled Prospective Study.

Background This study aimed to investigate the effectiveness of ultrasonography (US) and in vitro measurement (IVM) methods in localizing peripherally inserted central catheters (PICCs) in premature infants and analyze the relevant factors affecting the accuracy of IVM. Methodology The study employs a prospective before-and-after self-controlled clinical trial design. A total of 210 premature infants who underwent PICC catheterization were compared. We assessed the rate of catheter tip placement, consistency, and stability and analyzed the relevant factors. Results The study enrolled a total of 202 premature infants after eight infants dropped out. The one-time positioning rates of the PICC catheter tip using US and IVM were 100% and 73.8%, respectively. Concerning IVM, 53 (26.2%) patients did not reach the optimal position, with 24 (11.8%) patients having a shallow position and 29 (14.3%) having a deep position. The consistency of the two methods was 0.782 (p < 0.05). The degree of dispersion of US was 0.2 (0.0-0.4) cm, which was significantly smaller than IVM at 1.5 (0.0-1.8) cm. Gestational age less than 32 weeks (odds ratio (OR) = 6.64, 95% confidence interval (CI) = 1.43-30.81), weight less than 1,500 g (OR = 5.85, 95% CI = 2.11-16.20), body length less than 40 cm (OR = 15.36, 95% CI = 4.47-52.72), mechanical ventilation (OR = 5.13, 95% CI = 1.77-14.83), abdominal distension (OR = 78.18, 95% CI = 10.62-575.22), and bloating (OR = 8.81, 95% CI = 1.42-47.00) were risk factors that affected the accuracy of IVM. Conclusions Gestational age, weight, length, mechanical ventilation, abdominal distension, and swelling can lead to deviations with IVM. US can directly view the tip of the catheter, which is more accurate. Additionally, it is recommended to reduce the length of the catheter by 1.3 cm when using IVM to achieve the best-estimated placement length.

A home-based, post-discharge early intervention program promotes motor development and physical growth in the early preterm infants: a prospective, randomized controlled trial.

BACKGROUND: The implementation of early intervention (EI) in medical settings is time-consuming and resource-intensive, which limits its extensive use. In 2018, the Chinese Eugenics Association developed a home-based, post-discharge EI program. This study aims at evaluating the impact of this EI program on neurodevelopment and physical growth of early preterm infants. METHODS: This study was a prospective, partially blinded, randomized controlled trial (RCT), followed by an open phase. A total of 73 infants born at 28+ 0 ~ 31+ 6 weeks' gestation who were admitted to the Children's Hospital of Chongqing Medical University between December 1, 2019, and June 31, 2020, were enrolled. Another 33 infants were retrospectively recruited as the reference group. Thirty-seven infants randomized in the first early intervention, then standard care (EI-SC) group performed a 30-day EI during RCT period, while 36 infants allocated to SC-EI group were given EI in the following open phase. The test of infant motor performance (TIMP), development quotient (DQ), and anthropometric measures (length, weight, head circumference) were measured at the baseline (T0), termination of the RCT (T1), and termination of the open phase (T2). Repeated measures analysis was performed for comparison among groups. RESULTS: From T0 to T1, both groups had significant improvements in all outcome measures (all p < 0.001). A 30-day EI program was more effective in improving TIMP than standard care (from 53.12 ± 8.79 to 83.50 ± 11.85 in EI-SC group vs from 50.52 ± 8.64 to 75.97 ± 13.44 in SC-EI group, F = 4.232, p = 0.044). EI-SC group also had greater improvements in length, weight, and head circumference than SC-EI group (all p < 0.05). From T0 to T2, there was no significant difference regarding the improvements in all outcomes between the groups (all p > 0.05). At the endpoint of T2, the EI-SC and SC-EI group had similar TIMP and anthropometric measures, but much higher than the reference group (all p < 0.05). CONCLUSIONS: These findings demonstrated that a home-based, post-discharge EI program in this study was a practical approach to promote motor development and physical growth in early preterm infants. TRIAL REGISTRATION: CHICTR, CTR1900028330, registered December 19, 2019, https:// http://www.chictr.org.cn/showproj.aspx?proj=45706.

Femtosecond laser direct writing of few-mode depressed-cladding waveguide lasers.

We report on mirrorless laser operation of Nd:YVO4 single- and double-cladding waveguides fabricated by femtosecond laser direct writing. Fundamental- (LP01) and high-order-mode (LP03, LP05) guiding and lasing have been observed in waveguides with different geometries and sizes. Double-cladding waveguides exhibit good guiding and lasing performance via inheriting advantages respectively from individual single cladding. As a result, continuous-wave lasing with a threshold as low as 59 mW is obtained, depending on the optical feedback provided only by Fresnel reflections at the waveguide end faces. By using few-layer graphene as saturable absorber, passively Q-switched operation in fabricated waveguides is also achieved.

Two-photon luminescence thermometry: towards 3D high-resolution thermal imaging of waveguides.

We report on the use of the Erbium-based luminescence thermometry to realize high resolution, three dimensional thermal imaging of optical waveguides. Proof of concept is demonstrated in a 980-nm laser pumped ultrafast laser inscribed waveguide in Er:Yb phosphate glass. Multi-photon microscopy images revealed the existence of well confined intra-waveguide temperature increments as large as 200 °C for moderate 980-nm pump powers of 120 mW. Numerical simulations and experimental data reveal that thermal loading can be substantially reduced if pump events are separated more than the characteristic thermal time that for the waveguides investigated is in the ms time scale.

Optical lattice-like cladding waveguides by direct laser writing: fabrication, luminescence, and lasing.

We report on the fabrication of optical lattice-like waveguide structures in an Nd:YAP laser crystal by using direct femtosecond laser writing. With periodically arrayed laser-induced tracks, the waveguiding cores can be located in either the regions between the neighbored tracks or the central zone surrounded by a number of tracks as outer cladding. The polarization of the femtosecond laser pulses for the inscription has been found to play a critical role in the anisotropic guiding behaviors of the structures. The confocal photoluminescence investigations reveal different stress-induced modifications of the structures inscribed by different polarization of the femtosecond laser beam, which are considered to be responsible for the refractive index changes of the structures. Under optical pump at 808 nm, efficient waveguide lasing at ∼1 µm wavelength has been realized from the optical lattice-like structure, which exhibits potential applications as novel miniature light sources.

All-optical thermal microscopy of laser-excited waveguides.

We report on a unique combination of high-resolution confocal microscopy and ratiometric luminescence thermometry to obtain thermal images of 800 nm pumped ultrafast laser-inscribed waveguides in a Nd:YAG crystal. Thermal images evidence a strong localization of thermal load in the waveguide active volume. Comparison between experimental data and numerical simulations reveals that ultrafast laser-inscribed damage tracks in Nd:YAG crystals behave both as low-index and low-thermal conductivity barriers.

Polarization-dependent optical absorption of MoS2 for refractive index sensing.

As a noncentrosymmetric crystal with spin-polarized band structure, MoS2 nanomaterials have attracts increasing attention in many areas such as lithium ion batteries, flexible electronic devices, photoluminescence and valleytronics. The investigation of MoS2 is mainly focused on the electronics and spintronics instead of optics, which restrict its applications as key elements of photonics. In this work, we demonstrate the first observation of the polarization-dependent optical absorption of the MoS2 thin film, which is integrated onto an optical waveguide device. With this feature, a novel optical sensor combining MoS2 thin-film and a microfluidic structure has been constituted to achieve the sensitive monitoring of refractive index. Our work indicates the MoS2 thin film as a complementary material to graphene for the optical polarizer in the visible light range, and explores a new application direction of MoS2 nanomaterials for the construction of photonic circuits.

Three-dimensional dielectric crystalline waveguide beam splitters in mid-infrared band by direct femtosecond laser writing.

We report on the fabrication of three-dimensional waveguide beam splitters in a dielectric Bi(4)Ge(3)O(12) (BGO) crystal by direct femtosecond laser writing. In the laser written tracks of BGO crystal, positive refractive index is induced, resulting in so-called Type I configuration waveguiding cores. The "multiscan" technique is utilized to shape cores with designed cross-sectional geometry in order to achieve guidance at mid-infrared wavelength of 4 µm. The fundamental mode guidance along both TE and TM polarizations has been obtained in the waveguide structures. With this feature, we implement beam splitters from 2D to 3D geometries, and realize 1 × 2, 1 × 3, and 1 × 4 power splitting at 4µm.

Femtosecond-laser micromachined optical waveguides in Bi4Ge3O12 crystals.

The optical waveguides in Bi(4)Ge(3)O(12) (BGO) crystals in both depressed-cladding and dual-line configurations have been produced using femtosecond-laser micromachining. The guiding properties and thermal stabilities of the BGO waveguides have been investigated for both geometries, showing different performance of the fabricated structures. Both depressed-cladding and dual-line waveguides support guidance along both TE and TM polarizations. Thermal annealing treatments up to 600°C reduce the propagation loss of dual-line waveguides to as low as 0.5 dB/cm, while the cladding waveguide is only stable under thermal treatment not higher than 260°C, reaching a propagation loss of 2.1 dB/cm.