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Inflation is the leading theory of the first instant of the universe. Inflation, which postulates that the universe underwent a period of rapid expansion an instant after its birth, provides convincing explanation for cosmological observations. Recent advancements in detector technology have opened opportunities to explore primordial gravitational waves generated by the inflation through “B-mode” (divergent-free) polarization pattern embedded in the cosmic microwave background anisotropies. If detected, these signals would provide strong evidence for inflation, point to the correct model for inflation, and open a window to physics at ultra-high energies. LiteBIRD is a satellite mission with a goal of detecting degree-and-larger-angular-scale B-mode polarization. LiteBIRD will observe at the second Lagrange point with a 400 mm diameter telescope and 2622 detectors. It will survey the entire sky with 15 frequency bands from 40 to 400 GHz to measure and subtract foregrounds. The US LiteBIRD team is proposing to deliver sub-Kelvin instruments that include detectors and readout electronics. A lenslet-coupled sinuous antenna array will cover low-frequency bands (40–235 GHz) with four frequency arrangements of trichroic pixels. An orthomode-transducer-coupled corrugated horn array will cover high-frequency bands (280–402 GHz) with three types of single frequency detectors. The detectors will be made with transition edge sensor (TES) bolometers cooled to a 100 milli-Kelvin base temperature by an adiabatic demagnetization refrigerator. The TES bolometers will be read out using digital frequency multiplexing with Superconducting QUantum Interference Device (SQUID) amplifiers. Up to 78 bolometers will be multiplexed with a single SQUID amplifier. We report on the sub-Kelvin instrument design and ongoing developments for the LiteBIRD mission.

Background Family Integrated Care (FICare) has demonstrated positive outcomes for sick neonates and has alleviated the psychological burden faced by families. FICare involves structured training for professionals and caregivers along with the provision of resources to offer physical and psychological support to parents. However, FICare implementation has been primarily limited to developed countries. It remains crucial to assess the scalability of this model in overcoming social-cultural barriers and conduct a cost-effectiveness analysis. The RISEinFAMILY project aims to develop an adapted FICare model that can serve as the international standard for neonatal care, accommodating various cultural, architectural, and socio-economic contexts. Methods RISEinFAMILY is a pluri-cultural, stepped wedge cluster controlled trial conducted in Spain, Netherlands, the UK, Romania, Turkey, and Zambia. Eligible participants include infant-family dyads admitted to the Neonatal Intensive Care Unit (NICU) requiring specialised neonatal care for a minimum expected duration of 7 days, provided there are no comprehension barriers. Notably, this study will incorporate a value of implementation analysis on FICare, which can inform policy decisions regarding investment in implementation activities, even in situations with diverse data. Discussion This study aims to evaluate the scalability and adaptation of FICare across a broader range of geographical and sociocultural contexts and address its sustainability. Furthermore, it seeks to compare the RISEinFAMILY model with standard care, examining differences in short-term newborn outcomes, family mental health, and professional satisfaction. Trial registration ClinicalTrials.gov NCT06087666. Registered on 17 October 2023. Protocol version: 19 December 2022; version 2.2.

Animals can modify their body shape and/or color for protection, camouflage and communication. This adaptability has inspired fabrication of actuators with structural color changes to endow soft robots with additional functionalities. Using liquid crystal-based materials for actuators with structural color changes is a promising approach. In this review, we discuss the current state of liquid crystal-based actuators with structural color changes and the potential applications of these structural color actuators in soft robotic devices.Liquid crystal-based actuators with structural color changes and the potential applications of these structural color actuators in soft robotic devices are reviewed.

Cholesteric liquid crystal oligomers and polymers are promising materials for creating materials and devices with stimuli-responsive structural color, and the cholesteric to smectic pre-transition effect is of particular interest as it leads to a strong redshift in the reflected color upon cooling. Cholesteric polymers can be stabilized by the formation of semi-interpenetrating networks to obtain more robust photonic materials, but this tends to strongly suppress the pre-transition effect. Here, we show that the pre-transition effect in semi-interpenetrating networks based on main-chain cholesteric oligomers can be amplified by incorporating a smectic monomer and by increasing the degree of polymerization of the oligomers. This amplification counteracts the suppressing effect of the semi-interpenetrating network, and the resulting materials still show a significant band shift upon cooling. Presumably, both methods lead to the formation of more smectic domains in the cholesteric helix, which causes an amplified pre-transitional effect. The results bring us closer to the use of cholesteric semi-interpenetrating cholesteric networks for applications in smart sensing, healthcare, and safety devices.

Background There is increasing evidence that neonatal seizures in term neonates with stroke, asphyxia or brain haemorrhage might be associated with adverse neurodevelopment and development of epilepsy. The extent of this association is not known. The objective of this study was to assess the possible impact of neonatal seizures on these outcomes and if possible calculate a relative risk. Methods A systematic review and meta-analysis was performed (study period January 2000–June 2015). PubMed, Medline and Embase were searched for cohort studies evaluating neurodevelopmental outcome at the age of at least 18 months or development of epilepsy in surviving term neonates with or without neonatal seizures. The methodological quality of included studies was assessed and data extractions were performed in a standardized manner by independent reviewers. Pooled Relative Risks (RR) with 95% confidence intervals for adverse outcome were calculated if possible. Results Out of 1443 eligible studies 48 were selected for full text reading leaving 9 cohort studies for the final analyses (4 studies on stroke, 4 on perinatal asphyxia and one on cerebral hemorrhage). For all cases with stroke or asphyxia combined the pooled risk ratio (RR) for adverse outcome when suffering neonatal seizures was 7.42 (3.84–14.34); for neonates with perinatal asphyxia: 8.41 (4.07–17.39) and for neonates with stroke: 4.95 (1.07–23.0). The pooled RR for development of late onset epilepsy could only be determined for infants suffering from stroke: 1.48 (0.82–2.68). Results were biased and evidence sparse. Conclusions The presence of neonatal seizures in term newborns with vascular or hypoxic brain injury may have an impact on or be a predictor of neurodevelopmental outcome. The biased available data yield insufficient evidence about the true size of this association.

Cholesteric liquid crystals (CLCs) are a major class of photonic materials that display selective reflection properties arising from their helical ordering. The temperature response of CLCs, comprising dynamic reflection color changes upon variation of temperature, is exploited using material systems consisting of small mesogenic molecules, polymer‐dispersed liquid crystals (PDLCs), polymer‐stabilized liquid crystals (PSLCs), or liquid‐crystalline polymers. Taking advantage of the easy processability and flexibility of the molecular design, these temperature‐responsive CLCs are fabricated into different forms of photonic devices, including cells, coatings, free‐standing films, and 3D objects. Temperature‐responsive devices developed from CLCs are integrated for application in temperature sensors, energy‐saving smart windows, smart labels, actuators, and adding aesthetically pleasing features to common objects. Herein, the device capabilities of the different material systems of temperature‐responsive CLCs are summarized: small mesogenic molecules, PDLCs, PSLCs, and CLC polymers. For each system, examples of different device forms are presented, with their temperature responsiveness and the underlying mechanisms discussed. In addition, the potential of each material system for future device applications and product developments is envisioned. Temperature‐responsive cholesteric liquid crystals are an important class of photonic materials that show dynamic reflection properties upon temperature changes. The mechanisms that induce such temperature responses are discussed and related to the different molecular systems. A summary of design strategies, opportunities, challenges, and possible device structures is presented with a focus on photonic applications.

Frequency-domain multiplexing (fMux) is an established technique for the readout of large arrays of transition-edge sensor (TES) bolometers. Each TES in a multiplexing module has a unique AC voltage bias that is selected by a resonant filter. This scheme enables the operation and readout of multiple bolometers on a single pair of wires, reducing thermal loading onto sub-Kelvin stages. The current receiver on the South Pole Telescope, SPT-3G, uses a 68x fMux system to operate its large-format camera of ∼ 16,000 TES bolometers. We present here the successful implementation and performance of the SPT-3G readout as measured on-sky. Characterization of the noise reveals a median pair-differenced 1/f knee frequency of 33 mHz, indicating that low-frequency noise in the readout will not limit SPT-3G’s measurements of sky power on large angular scales. Measurements also show that the median readout white noise level in each of the SPT-3G observing bands is below the expectation for photon noise, demonstrating that SPT-3G is operating in the photon-noise-dominated regime.

We present on the status of POLARBEAR-2 A (PB2-A) focal plane fabrication. The PB2-A is the first of three telescopes in the Simons Array, which is an array of three cosmic microwave background polarization-sensitive telescopes located at the POLARBEAR site in Northern Chile. As the successor to the PB experiment, each telescope and receiver combination is named as PB2-A, PB2-B, and PB2-C. PB2-A and -B will have nearly identical receivers operating at 90 and 150 GHz while PB2-C will house a receiver operating at 220 and 270 GHz. Each receiver contains a focal plane consisting of seven close-hex packed lenslet-coupled sinuous antenna transition edge sensor bolometer arrays. Each array contains 271 dichroic optical pixels, each of which has four TES bolometers for a total of 7588 detectors per receiver. We have produced a set of two types of candidate arrays for PB2-A. The first we call Version 11 (V11) uses a silicon oxide (SiO x ) for the transmission lines and crossover process for orthogonal polarizations. The second we call Version 13 (V13) uses silicon nitride (SiN x ) for the transmission lines and cross-under process for orthogonal polarizations. We have produced enough of each type of array to fully populate the focal plane of the PB2-A receiver. The average wirebond yield for V11 and V13 arrays is 93.2% and 95.6%, respectively. The V11 arrays had a superconducting transition temperature ( T c ) of 452 ± 15  mK, a normal resistance ( R n ) of 1.25 ± 0.20 Ω , and saturation powers of 5.2 ± 1.0  pW and 13 ± 1.2  pW for the 90 and 150 GHz bands, respectively. The V13 arrays had a superconducting transition temperature ( T c ) of 456 ± 6  mK, a normal resistance ( R n ) of 1.1 ± 0.2 Ω , and saturation powers of 10.8 ± 1.8  pW and 22.9 ± 2.6  pW for the 90 and 150 GHz bands, respectively. Production and characterization of arrays for PB2-B are ongoing and are expected to be completed by the summer of 2018. We have fabricated the first three candidate arrays for PB2-C but do not have any characterization results to present at this time.

Digital Frequency-Domain Multiplexing (DfMux) is a technique that uses MHz superconducting resonators and Superconducting Quantum Interference Device (SQUID) arrays to read out sets of transition edge sensors. DfMux has been used by several Cosmic Microwave Background experiments, including most recently POLARBEAR-2 and SPT-3 G with multiplexing factors as high as 68, and is the baseline readout technology for the planned satellite mission LiteBIRD . Here, we present recent work focused on improving DfMux readout noise, reducing parasitic impedance, and improving sensor operation. We have achieved a substantial reduction in stray impedance by integrating the sensors, resonators, and SQUID array onto a single-carrier board operated at 250 mK. This also drastically simplifies the packaging of the cryogenic components and leads to better-controlled crosstalk. We demonstrate a low readout noise level of 8.6 pA / Hz 1 1 / 2 , which was made possible by operating the SQUID array at a reduced temperature and with a low dynamic impedance. This is a factor of two improvement compared to the achieved readout noise level in currently operating Cosmic Microwave Background experiments using DfMux and represents a critical step toward maturation of the technology for the next generation of instruments.

The Simons Array (SA) is a cosmic microwave background (CMB) polarization experiment comprised of three telescopes that will observe the CMB at 90, 150, 220, and 270 GHz with more than 22,000 Transition Edge Sensor (TES) bolometers. The cryogenic receivers inside each telescope are named POLARBEAR-2a, POLARBEAR-2b, and POLARBEAR-2c (PB-2a, PB-2b, and PB-2c, respectively). To allow for the large number of detectors, SA uses frequency-division multiplexing with multiplexing factor of 40. We describe the process developed to assemble the readout circuit repeatably for SA. After assembly, we characterize the readout circuit and TESs at cryogenic temperatures in a condition of negligible incident optical power. Impedances in the readout circuit bias our estimates of TES parameters, and we describe a method to account for this.