bluuebunny/crossref_metadata_2025 huggingface dataset:
Dual‐band high‐efficiency power amplifier using a D‐CRLH harmonic tuning network
Authors: Cai Qi , Xue Quan , Che Wenquan
Published: March 2022

One dual‐band high‐efficiency power amplifier (PA) based on a D‐CRLH structure is presented. The D‐CRLH cell is employed to realize one dual‐band second harmonic trapping for the two operation frequency bands. Based on above design strategy, high PA efficiency at two frequency bands can be achieved by transferring the fundamental and second harmonic impedances to appropriate positions on the Smith chart. For demonstration, one prototype is designed at 2.3 and 3.5 GHz by using the proposed design strategy. The results indicate one peak output power of 40 and 40.8 dBm at the measured frequency of 2.2 and 3.2 GHz, respectively, while the maximum power‐added efficiencies (PAE) are 73.9% and 64% at the two frequencies.
Modeling method for grounded coplanar waveguide with vector fitting technique
Authors: Tan Daidao , Lu Hongliang , Zhao Ranran , Qi Junjun , Zhang Yimen , Zhang Yuming , Cheng Wei
Published: March 2022

In this article, a semiempirical equivalent circuit model of the grounded coplanar waveguide (GCPW) based on the vector fitting is proposed for the first time, which improves the accuracy in high frequency. It offers an effective solution for the millimeter GCPW modeling. This model takes into account nonideal effects such as skin effect and substrate coupling effect, which realizes the combination of numerical method and physical meaning. The method we propose aims to use sequential quadratic programming algorithm to solve strictly passive problems. Good agreement is obtained between the modeled and measured data up to 40 GHz.
Low‐insertion‐loss planar four‐way Gysel power divider with high isolation employing two‐layer substrates
Authors: Song Kaijun , Li Qian , Chen Yuxuan , Hu Shunyong
Published: March 2022

This paper presents a kind of novel planar four‐way Gysel power divider that has high isolation and low insertion loss (IL). This power divider adopts two‐layer substrates. The power divider circuit and isolation circuit are on different layers. For analysis and design, an equivalent circuit is given. The relationship between the impedance of the matching section and the working bandwidth is analyzed. The design process is given to illustrate a specific method that also applies to the N‐way Gysel power divider. For verification, a prototype is designed, manufactured. The measured results show that IL is 6.3 ± 0.1 dB approximately. The 20 dB relative isolation bandwidth achieves 45%. Between 1.88 and 2.64 GHz, the input return loss (RL) achieves 15 dB. And between 1.78 and 2.75 GHz, the output RL is better than 15 dB.
A high selectivity tri‐band BPF using π‐type structure loaded with λ/4 open stub and hybrid SIR
Authors: Zhu Lin , Guan Yangyang , Zheng Bangjie , Cheng Zhiqun
Published: March 2022

In this letter, a novel tri‐band bandpass filter (BPF) with high selectivity is presented. The proposed tri‐band BPF employs a symmetrical π‐type structure loaded with λ/4 open stubs and hybrid stepped impedance resonator (SIR). The hybrid SIR consists of two‐section cascaded SIR and a pair of parallel‐coupled lines. Using λ/4 frequency‐selected open stubs, the complete π‐type structure is restructured into a basic π‐type structure with three microstrip lines. The filtering responses of the second passband are controlled only by the basic π‐type structure. The filtering responses of the first and third passbands are influenced by the complete π‐type structure. By embedding coupled‐lines into the two‐section cascaded SIR, four extra transmission zeros (TZs) are obtained. For validation, a tri‐band BPF with 3‐dB fractional bandwidths of 14.3%, 9.4%, and 6.6%, respectively, operating at 1.77 GHz (GSM), 2.37 GHz (WLAN), and 3.43 GHz (WiMAX) is simulated, fabricated, and measured. The measured insertion losses are less than 1.5 dB and return losses are better than 24.5 dB within three passbands. In total, seven TZs are generated and the maximum roll‐off rate of three passbands is up to 173 dB/GHz. The good agreement between simulations and measurements verifies the proposed design.
Design of a pattern reconfigurable antenna for wide‐angle scanning phased array applications
Authors: Cao Yuanxi , Feng Penghao , Yan Sen
Published: March 2022

In this article, a pattern reconfigurable antenna is proposed for wide beam scanning phased array applications. Different from the wide beamwidth unit design, the large beam scanning range of the proposed antenna array is realized by the reconfigurable radiation patterns with the different tilted angles of the antenna unit. The tilted beams can enhance the total beam coverage range of the antenna unit with high directivity, thus increasing the beam scanning range of the antenna array. The tilted beams are realized by the combination of the concentric circular and annular patch antennas. A PIN diode‐loaded reconfigurable feeding network is designed to feed the patches with reconfigurable phase differences. The feeding network can achieve a good impedance matching effect and guarantee the symmetry of the tilted beams. To verify the beam scanning performance of the proposed antenna, a 1 × 4 linear array is fabricated and measured. The results prove that the antenna can achieve ±61° beam scanning range with ±78° 3 dB beam coverage range and the maximum sidelobe level (SLL) of −8.0 dB. The characteristics include low‐profile, high efficiency, low SLL, and wide beam scanning range making it a very attractive choice for phased array antenna applications.
Interferometer direction‐finding system with time‐division multiplexing of spread spectrum signals
Authors: Zhang Jiebing , Feng Wenquan , Xu Yong
Published: March 2022

A single channel interferometer direction‐finding (DF) system is proposed in this article. The interferometer DF system adopts time‐division multiplexing to receive different antenna phase information, which can effectively eliminate the differences in time delay and channel gain due to different channels. In addition, the spread spectrum signal and integer ambiguity resolution algorithm are used to make the system suitable for low carrier‐to‐noise ratios (CNRs) and high‐frequency signals. The simulations show that the system can measure the angle with root mean square error accuracy at a CNR of 50 dB‐Hz.
Vehicle‐mounted mobile mid‐infrared high‐precision atmospheric ethane sensor system
Authors: Zhang Lei , Yan Ge , Yu Ling , Song Fang , Yang Yue , Wang Qing , Li Xiuying , Zheng Chuantao , Wang Yiding
Published: March 2022

Ethane (C2H6) is an important gas in environmental monitoring, especially in urban areas, and the development of vehicle‐mounted mobile C2H6 sensors is meaningful for high‐efficiency and wide‐range detection of C2H6 concentration levels. Based on tunable diode laser absorption spectroscopy, a sensor system for the detection of trace C2H6 concentration in the atmosphere was developed using wavelength modulation spectroscopy. An interband cascade laser with a central wavelength of 3337 nm and a multipass gas cell (MPGC) with an optical path length of 26.4 m was used as core optical components. The pressure in the MPGC was optimized at 200 Torr, and such pressure was stabilized by a self‐developed pressure control system. The sensor system was compactly integrated into a standalone instrument with a dimension size of 52 × 33 × 28.8 cm3. The detection limit (1σ) was measured to be 3.45 parts per billion at an averaging time of 0.5 s. Forty‐eight‐hour field experiment and vehicle‐mounted mobile measurement of atmospheric C2H6 levels with concentration mapping were carried out on the Jilin University campus to validate the practical application ability of the system.
A compact self‐packaged triple‐mode bandpass filter using dual capacitively‐loaded substrate‐integrated waveguide resonator
Authors: Jing Huaishu , Zhang Yonghong , Qu Lili , Jing Shouzhao , Liu Jiawei , Bo Xiaole
Published: March 2022

A compact triple‐mode (TM) bandpass filter (BPF) is designed based on the proposed dual capacitively‐loaded (DCL) substrate‐integrated waveguide (SIW) resonator. Two identical T‐shaped grounded striplines are inserted into a square SIW cavity to generate a capacitively loading effect without damaging cavity surface integrity, which contributes to maintaining EM‐shielding capability. By adjusting the size and position of the DCL structure, the first three resonant modes, including TE101, TE201, and TE301 are easily controlled to design a TM‐BPF. A transmission zero (TZ) is introduced by the grounded striplines and flexibly controlled. TZ is tuned to suppress the TE102 mode to acquire a wide upper rejection band. Furthermore, the filter design procedures are presented in the context under specified filter performance. Finally, to verify the proposed design method, an example of self‐packaged TM‐BPF at 6 GHz with a good lower stopband and a wide upper rejection band is designed, fabricated, and measured. The measured results are in good agreement with simulated ones.
A compact Ka‐band limiter‐low noise amplifier MMIC with high power capability
Authors: Yang Lin , Zhang Ming , Wang Jianchao , Wang Baozhu , Yu Pingping , Wu Ruihong
Published: March 2022

This paper presents a 30–36 GHz limiter low‐noise amplifier (limiter‐LNA) MMIC for high power and high mobility millimeter‐wave radar systems. The PIN‐diode limiter network and the LNA are codesigned to realize high input‐power handling capability, good small‐signal performance, and small chip area. A two‐state matching capacitor is presented to improve both the input‐power handling capability at the high input‐power level and the input return loss at the small‐signal level. The proposed circuit is fabricated with a combined PIN/0.15‐µm‐GaAs‐pHEMT process. The limiter‐LNA is capable of handling 39 dBm continuous wave (CW) input‐power without failure with only two limiter stages. The measured noise figure is 1.8–2.5 dB, the small‐signal gain is 18.5 ± 0.5 dB, the output power at 1 dB compression point is larger than 11 dBm, and the dc power consumption is 72 mW. The chip area, including testing pads, is only 2.1 mm × 1.0 mm. This limiter‐LNA MMIC is believed to have the highest input‐power handling capability and smallest chip area among limiter‐LNA MMICs at this frequency range reported up to date.
Design and simulation of differential transimpedance amplifier with active feedback for optical receivers
Authors: Duraiswamy Punithavathi , Anusha U. , Raghu S. , Selvaraja Shankar K.
Published: March 2022

An active feedback network‐based bandwidth extension technique for CMOS differential transimpedance amplifier (TIA) is proposed in 0.18 µm CMOS process technology. The design consists of three stages in differential mode. The first stage is a common‐source amplifier that minimizes noise. A common collector stage is used for level shifting and buffering in the second stage. The third stage is a differential amplifier that provides additional gain. In addition to these three stages, an active CMOS negative feedback circuit is used for extending the bandwidth. The proposed design achieves a gain of 45.2 dBΩ with a 3 dB bandwidth of 21.23 GHz. The active feedback circuit provides an additional bandwidth of 7.3 GHz. The TIA achieves a data rate of 30 Gb/s with input‐referred noise current density of 63.1 pA/ and jitter of 9.07 ps. The TIA consumes a power of 10.3 mW with a supply voltage of 1.8 V.
Refractive index sensing properties of microfiber cascaded‐long‐tapers
Authors: Liu Fuhua , Wang Yu , Dang Hongtao , Li Jin
Published: March 2022

The microfiber cascaded double‐tapers were constructed and used as a Mach–Zehnder interferometer by a two‐step fiber stretching process using a normal fiber splicer and a multifunctional fiber stretching machine. The morphological parameters, such as waist diameter and taper length were optimized by the simulation models. The refractive index sensing performance has been theoretically and experimentally demonstrated and compared. A sensitivity of 2606.39 nm/RIU of one Mach–Zehnder interferometer with microfiber double‐apers (central distance is ~1 cm) was obtained when the RI values changed from 1.3309, 1.3319, 1.3327, 1.3336, 1.3344–1.3352. This study proposed a novel way to design interesting microfiber devices, which will be a promising candidate for exploring optical fiber biosensors with compact structures.
Social, behavioural, and functional characteristics of community‐dwelling South Korean adults with moderate and severe cognitive impairment
Authors: Nam Sanghun , Downer Brian , Bae Suyeong , Hong Ickpyo
Published: March 2022

Objectives

This study used the 2016 Korean Longitudinal Study on Aging to investigate the social, behavioural, and functional characteristics of community‐dwelling South Korean adults with cognitive impairment.

Methods

Participants were classified as normal, moderate impairment, and severe impairment according to an algorithm that combined the Korean Mini‐Mental State Examination score and the number of difficulties in performing instrumental activities of daily living. Selected characteristics included grip strength, depression, participation in exercise and social activities, and living in a rural, urban, or suburban community.

Results

Most (72.7%) participants were classified as having normal cognition, 20.1% were classified as moderate impairment, and 7.2% were classified as severe impairment. Regardless of sex, the differences in grip strength across the cognitive status classifications were statistically significant, except for the difference between moderate and severe cognitive impairment in males (p = 0.8477). Greater number of depressive symptoms and living in rural areas were associated with significantly higher odds for severe cognitive impairment. Participants with moderate (OR = 0.51) and severe (OR = 0.33) cognitive impairment were less likely to participate in social activities than those with normal cognition.

Conclusions

The study findings revealed that social, behavioural, and functional characteristics are closely related to the cognitive status of community‐dwelling adults in South Korea.
You cannot fight the pressure: Structural rearrangements of active pharmaceutical ingredients under magic angle spinning
Authors: Scheidel Sebastian , Östreicher Laurina , Mark Isabelle , Pöppler Ann‐Christin
Published: March 2022

Although solid‐state nuclear magnetic resonance (NMR) is a versatile analytical tool to study polymorphs and phase transitions of pharmaceutical molecules and products, this work summarizes examples of spontaneous and unexpected (and unwanted) structural rearrangements and phase transitions (amorphous‐to‐crystalline and crystalline‐to‐crystalline) under magic angle spinning (MAS) conditions, some of them clearly being due to the pressure experienced by the samples. It is widely known that such changes can often be detected by X‐ray powder diffraction (XRPD); here, the capability of solid‐state NMR experiments with a special focus on 1H‐13C frequency‐switched Lee–Goldburg heteronuclear correlation (FSLG HETCOR)/MAS NMR experiments to detect even subtle changes on a molecular level not observable by conventional 1D NMR experiments or XRPD is presented. Furthermore, it is shown that a polymorphic impurity combined with MAS can induce a crystalline‐to‐crystalline phase transition. This showcases that solid‐state NMR is not always noninvasive and such changes upon MAS should be considered in particular when compounds are studied over longer time spans.
No gain without pain education: Improving knowledge and biopsychosocial attitudes and beliefs in a predominantly non‐health‐related undergraduate target audience
Authors: Fitzgerald Kylie , Vaughan Brett , Devonshire Elizabeth , Schneider Carl , Denham Rebecca
Published: March 2022

Objectives

Chronic pain (CP) impacts individuals and society and is the leading cause of disability globally. Pain education interventions are often evaluated in patients and health professional students, but not in non‐health student groups. Increasing knowledge of pain may facilitate shifts in attitudes and beliefs towards sufferers. We report on changes in pain knowledge, attitudes and beliefs of predominantly non‐health‐related tertiary degree students participating in online education.

Methods

Quantitative cohort study design. Students reported demographics and completed the Chronic Pain Myth Scale and 12‐item Neurophysiology of Pain Questionnaire (NPQ) before (T1) and after (T2) the 7‐week online module at The University of Sydney in 2020.

Results

Twenty‐two students undertaking predominantly non‐health‐related bachelor's degrees (16.5% response rate, 90.9% female, mean = 19.5 years) participated. NPQ scores increased from 47.3% to 62.9%. Attitudes and beliefs towards biopsychosocial impact improved (p < 0.027) but not towards individuals suffering from CP or treatment of CP. A negative correlation was found between age and people suffering from CP (ρ = −0.437, p < 0.042) and age and towards treatment of CP; ρ = −0.556, p < 0.007) at T2.

Conclusion

Completing the elective online module resulted in improved knowledge and biopsychosocial attitudes towards CP in this predominantly non‐health cohort, as reported in health and patient cohorts.
Does Moon Phase Affect Indices of Kokanee Size and Abundance as Characterized by Gill-Net Catch?
Authors: Branigan Philip R. , Washburne Emily F. , Meyer Kevin A.
Published: March 2022

Many pelagic fish species such as kokanee Oncorhynchus nerka undertake diel vertical migration in response to dynamic interactions between ambient light, foraging opportunity, and predation risk. Consequently, kokanee populations are almost universally sampled during the dark phase of the moon (i.e., the new moon), presumably to optimize capture efficiency. However, it is unclear if this sampling precaution is necessary to avoid bias in kokanee catch data related to the moon phase. We used experimental gill nets to sample kokanee populations in two thermally stratified reservoirs during three distinct moon phases (i.e., new, first quarter, and full) to understand the relative effects of moon phase and other ambient light variables on total catch and average size of captured kokanee. The total catch of kokanee differed significantly between populations but was not significantly affected by moon phase, secchi depth, or net depth. The average size of kokanee sampled from both populations increased significantly with moon illuminance and likely reflects behavior associated with predator–prey dynamics. Results from this case study suggest that the effect of moon phase and other ambient light variables on gill-net catch composition of kokanee is likely population-specific and is governed in part by population parameters such as abundance, growth rate, and size-structure. As such, investigators should be cognizant of—or perhaps standardize gill-net samples to—ambient light variables when indexing populations of kokanee and other pelagic fishes that undertake diel vertical migrations, especially when size indices are examined.
A novel antisymmetric 16‐element transceiver dipole antenna array for parallel transmit cardiac MRI in pigs at 7 T
Authors: Elabyad Ibrahim A. , Terekhov Maxim , Lohr David , Bille Maya , Hock Michael , Schreiber Laura M.
Published: March 2022

To improve parallel transmit (pTx) and receive performance for cardiac MRI (cMRI) in pigs at 7 T, a dedicated transmit/receive (Tx/Rx), 16‐element antisymmetric dipole antenna array, which combines L‐shaped and straight dipoles, was designed, implemented, and evaluated in both cadavers and animals in vivo. Electromagnetic‐field simulations were performed with the new 16‐element dipole antenna array loaded with a pig thorax‐shaped phantom and compared with an eight‐element array of straight dipoles. The new dipole array was interfaced to a 7 T scanner in pTx mode (8Tx/16Rx). Imaging performance of the novel array was validated through MRI measurements in a pig phantom, an 85 kg pig cadaver, and two pigs in vivo (74 and 81 kg). Due to the improved decoupling between interleaved L‐shaped and straight dipole elements, the 16‐element dipole array fits within the same outer dimensions as an eight‐element array of straight dipoles. This provides improvement of both transmit and receive characteristics and additional degrees of freedom for
shimming. The antisymmetric dipole array demonstrated efficient suppression of destructive interferences in the
field, with up to 25% improvement in the
homogeneity achieved using static pTx‐RFPA
shimming in comparison with the hardware‐adjusted state, which was optimized for single transmit. High‐resolution (0.5 × 0.5 × 4 mm3) anatomical images of the heart after cardiac arrest proved good transmit and receive characteristics of the novel array design. Parallel imaging with an acceleration factor up to R = 6 was possible while maintaining a mean g factor of 1.55 within the pig heart. CINE images acquired in vivo in two pigs demonstrated SNR and parallel imaging capabilities similar to those of a reference 8Tx/16Rx dedicated loop array for cMRI in pigs.
Gurson–Tvergaard–Needleman model guided fracture‐resistant structural designs under finite deformations
Authors: Zhang Guodong , Khandelwal Kapil
Published: March 2022

A finite strain shear modified Gurson–Tvergaard–Needleman (GTN) model based on multiplicative elastoplasticity, together with its implementation details, is presented. This GTN model which can simulate the loss of load‐carrying capacity of porous metals through nucleation, growth, shearing, and coalescence of voids is incorporated in an optimization framework for designing structures with optimal plastic energy dissipation capacity while satisfying prescribed constraints on material usage and damage. An adjoint method‐based analytical path‐dependent sensitivity analysis is presented that can be used with gradient‐based optimization algorithms. Using the proposed topology optimization formulations, the optimized designs exhibit well‐constrained fracture at the design displacements. Ultimate performance analyses of the optimized designs demonstrate that the fracture‐resistant designs can have higher ductility, ultimate strength as well as improved energy dissipation, as compared to the designs guided by von Mises plasticity where no fracture mechanisms are modeled. Moreover, due to finite deformations, a fracture can initiate at multiple locations and critical fracture locations can change during the loading process. In addition, different failure modes are revealed from different optimized designs under large deformations.
A fifth–sixth century CE lynx (Lynx lynx L., 1758) skeleton from Hungary: Cranial morphology and zoological interpretations
Authors: Gál Erika , Bartosiewicz László , Kiss Viktória
Published: March 2022

The articulated skeleton of an adult male lynx was found in association with four dogs and scattered bones of other domesticates in a pit at Zamárdi‐Kútvölgyi‐dűlő II, Hungary. Lynx remains occur rarely in the archaeological record, and protocols for ageing and sexing do not exist. The intact skull of the skeleton offered an opportunity to review the craniological features of the species in comparison with a reference material of extant individuals, complementing our knowledge of lynx osteology, providing an empirical basis for zooarchaeological evaluation. Although caution is due in assigning a concrete function to the curious Zamárdi deposit, familiarity with the craniological properties, habitat preferences, and behavior of Eurasian lynx is indispensable in cultural interpretations subject to a forthcoming study on the osteoarchaeology of this rare wild felid.
Multi‐modal cell structure formation of poly (lactic‐co‐glycolic acid)/superparamagnetic iron oxide nanoparticles composite scaffolds by supercritical CO2 varying‐temperature foaming
Authors: Zhang Yi , Wang Jinjing , Zhou Jiancheng , Sun Jianfei , Jiao Zhen
Published: March 2022

Poly (lactic‐co‐glycolic acid) (PLGA)/superparamagnetic iron oxide nanoparticles (SPIONs) composite scaffold material was prepared by supercritical carbon dioxide varying‐temperature mode method. The multi‐modal cell structure was formed, and the mechanism was explained. The nuclei formed in the heating stage grew into large pores, while the nuclei formed in the depressurization stage grew into small pores. SPIONs caused pores to rupture and coalesce into small pores or large pores. The effects of foaming parameters, including the amount of SPIONs, saturation temperature, foaming temperature, foaming pressure, and depressurization rate on the properties of the scaffolds, were systematically studied. The results showed that the addition of SPIONs could improve the porosity and mechanical properties of the scaffold, and the obvious multi‐modal cell structure could be formed. In conclusion, by changing the foaming parameters, the PLGA/SPIONs composite scaffolds with various average diameters (11.93–790.52 μm), a wide range of porosity (62.98%–93.23%) and mechanical properties (0.38–11.12 MPa) could be obtained.
Advanced Kolarik model for the modulus of a nanocomposite system reinforced by halloysite nanotubes and interphase zone
Authors: Zare Yasser , Rhee Kyong Yop
Published: March 2022

In the current article, Kolarik model is progressed for the tensile modulus of a polymeric system containing dispersed halloysite nanotubes (HNT) and adjacent interphase section. The progressive model correlates the nanocomposite's modulus to HNT concentration (volume fraction and weight percentage), the extents of HNT and nearby interphase section in addition to the densities of polymer medium and HNT. The productions of the progressive model are linked to the tentative results and the influences of all variables on the modulus of system are justified. The modulus of system reduces as HNT radius increases, but HNT weight percentage directly controls the nanocomposite's modulus. The modulus of samples maximizes by 47% by the deepest interphase section of 20 nm establishing a straight link among nanocomposite's modulus and interphase thickness. The increment of polymer matrix density improves the modulus of samples, but there is an opposite relation between the modulus of system and HNT density. Furthermore, the calculations exactly match to the experimental facts of numerous examples representing the accurateness of the progressed model.
Being born with a single cardiac ventricle: What do we tell prospective parents
Authors: d'Udekem Yves , Hutchinson Darren
Published: March 2022

Single ventricle cardiac disease remains one of the most extreme forms of congenital heart disease. It encompasses a wide variety of lesions characterised by the existence of one small ventricular cavity. We now realise that survival of this group is much longer than expected, well into adulthood for the majority with current techniques, albeit with a considerable burden of disease for many. Here we give a up to date review of single ventricle cardiac disease. We include discussion regarding prenatal assessment and planning, usual treatment pathways, short and long term outcomes and a discussion on the future for this patient group. We combine this information to give a contemporary perspective on our counselling approach appropriate for those who are the first contact and primary conveyors of this information to families.
Implementation of non‐invasive prenatal testing within a national UK antenatal screening programme: Impact on women's choices
Authors: Bowden Bethan , de Souza Sikha , Puchades Alice , Williams Kindry , Morgan Sian , Anderson Sarah , Tucker David , Hillier Sharon
Published: March 2022

Objective

To evaluate the implementation of non‐invasive prenatal testing (NIPT) on pregnant women's choices in a national NHS antenatal screening programme for Down's syndrome, Edwards' syndrome and Patau's syndrome.

Method

An observational study of all pregnant women with a singleton pregnancy and higher chance (≤1:150) combined or quadruple screening result from 30 April 2018 to 25 September 2020 in Wales, UK. Pregnant women's journey through the pathway was determined including uptake of NIPT, performance of NIPT in a non‐research setting and invasive procedures performed.

Results

Of the 1273 women with a higher chance initial screening, 1073 (84%) chose NIPT contingent test, 174 (14%) no further testing and 26 (2%) invasive procedure. There were 1001 (93%) low chance NIPT results; 11 (1%) failed results and 61 (6%) high chance results. Average annual incidence of 27 invasive procedures undertaken compared to 229 pre‐NIPT implementation, a nearly ninefold reduction. Down's syndrome annual live birth rate remained unchanged across the implementation period.

Discussion

This study demonstrates that NIPT contingent screening was highly acceptable to women with a resulting reduction in invasive procedures performed.

Conclusion

The high uptake of NIPT in NHS antenatal screening pathway conditions should inform planning for other national screening programmes.
Techno‐economic analysis of the use of atomic layer deposited transition metal oxides in silicon heterojunction solar cells
Authors: Chang Nathan L. , Poduval Geedhika K. , Sang Borong , Khoo Kean , Woodhouse Michael , Qi Fred , Dehghanimadvar Mohammad , Li Wei Min , Egan Renate J. , Hoex Bram
Published: March 2022

The industry for producing silicon solar cells and modules has grown remarkably over the past decades, with more than a 100‐fold reduction in price over the past 45 years. The main solar cell fabrication technology has shifted over that time and is currently dominated by the passivated emitter and rear cell (PERC). Other technologies are expected to increase in market share, including tunnel‐oxide passivated contact (TOPCon) and heterojunction technology (HJT). In this paper, we examine the cost potential for using atomic layer deposition (ALD) to form transition metal oxide (TMO) layers (
,
and aluminium‐doped zinc oxide [AZO]) to use as lower cost alternatives of the p‐doped, n‐doped and indium tin oxide (ITO) layers, respectively, the layers normally used in HJT solar cells. Using a bottom‐up cost and uncertainty model with equipment cost data and process experience in the lab, we find that the production cost of these variations will likely be lower per wafer than standard HJT, with the main cost drivers being the cost of the ALD precursors at high‐volume production. We then considered what efficiency is required for these sequences to be cost effective in $/W and discuss whether these targets are technically feasible. This work motivates further work in developing these ALD TMO processes to increase their efficiency towards their theoretical limits to take advantage of the processing cost advantage.
Damp‐heat induced degradation in photovoltaic modules manufactured with passivated emitter and rear contact solar cells
Authors: Kyranaki Nikoleta , Smith Alex , Yendall Keith , Hutt David A. , Whalley David C. , Gottschalg Ralph , Betts Thomas R.
Published: March 2022

Corrosion is one of the main PV module failure mechanisms, as it can cause severe electrical performance degradation in PV modules exposed to hot and humid environments. Moisture penetrating a photovoltaic (PV) module may react with the metallic components causing corrosion. In addition, acetic acid which is produced by hydrolysis of ethylene vinyl acetate (EVA), the most common encapsulant, may further degrade metallic components. Corrosion is one of the main PV module failure mechanisms, as it can cause severe electrical performance degradation in PV modules exposed to hot and humid environments. The specific chemical reactions involved in the corrosion mechanisms for the different components are well understood. However, which of these causes the most serious degradation in the field, and therefore, most severe power loss is unknown. Moreover, the severity of corrosion in the absence of acetic acid is not yet well researched. This work distinguished between the front and rear side corrosion mechanisms and identified the different electrical signatures observed due to them. The experiment included damp‐heat (DH) conditioning of single‐cell mini‐modules, containing passivated emitter and rear contact (PERC) solar cells, laminated with a polyethylene terephthalate (PET) based backsheet. Furthermore, half‐encapsulated PERC PV cells were tested, with either the front or the rear side exposed. Electrical and material characterisation were conducted for the investigation of the sample degradation, and the performance decrease, related to the degradation of the rear surface passivation, was examined.
An insight into major signaling pathways and protein–protein interaction networks involved in the pathogenesis of gestational diabetes mellitus
Authors: Chatterjee Bhaswati , Neelaveni Kudugunti , Kenchey Himaja , Thakur Suman S.
Published: March 2022

Gestational diabetes mellitus (GDM) is associated with the increase of glucose in the blood rather than being absorbed by the cells. A better understanding of the signaling pathways is necessary to understand the pathophysiology of GDM. This study provides details about a series of signaling pathways and protein–protein interactions involved in the pathogenesis of GDM and their evaluations in GDM development. Protein–protein interactions were found between proteins of several signaling pathways that suggest interlink between these signaling pathways. Protein–protein interactions were generated with high confidence interaction scores based on textmining, cooccurrence, coexpression, neighborhood, gene fusion, experiments, and databases. The dysregulation of signaling pathways may also contribute to the increased risk of complications associated with GDM in the mother and child. Further, studies on signaling pathways involved in the pathogenesis of GDM would help in the development of an effective intervention to prevent GDM along with the identification of key targets for effective therapies in the future.
Psychosocial assessment of candidates for hematopoietic cell transplantation: A national survey of centers' practices
Authors: Randall Jill , Anderson Georgia , Kayser Karen
Published: March 2022

Objective

This study characterizes pre‐hematopoietic cell transplant psychosocial assessment practices with adult patients at centers in the U.S. An online, cross‐sectional survey was conducted to describe the content and process of assessment including the high risk factors that influence transplant eligibility and how eligibility decisions are made.

Methods

Psychosocial professionals (one per center) were invited to participate by sharing their center's practice. The questionnaire was developed by the researchers and pre‐tested with a group of hematopoietic cell transplantation social workers. Univariate statistics were used to describe the sample as well as the content and process of psychosocial assessment. Content analysis was conducted on textual data.

Results

A total of 90 centers had one psychosocial professional that responded. There was general consistency among centers about the major psychosocial components that are assessed, but variation occurred regarding what, if any, standardized measures were used. Approximately half of centers that used standardized measures used the Psychosocial Assessment of Candidates for Transplantation, Transplant Evaluation Rating Scale, or Stanford Integrated Psychosocial Assessment for transplantation to rate overall psychosocial risk. Most respondents (86%) reported that their center has declined an otherwise medically eligible patient due to psychosocial risk factors. Risk factors most frequently reported as potentially influencing eligibility included no caregiver/poor support system, illicit drug use, and serious, untreated mental illness.

Conclusions

Study findings provide a fuller understanding of psychosocial assessment practices, including the challenging ethical issue of psychosocial eligibility, and will help inform best practices.
Plasma surface technology for CO2‐neutral and sustainable mobility
Authors: Hosenfeldt Tim
Published: March 2022

Three concepts are suitable for CO2‐neutral and sustainable mobility: First, the direct use of electrical energy for battery electric vehicles. Second, the conversion of regeneratively generated electricity into green hydrogen as an energy carrier for fuel cell electric vehicles, and third, the generation of synthetic fuels from green hydrogen. The technologies will complement each other in terms of vehicle weight, driving distance, and propulsion power required. Regardless of the powertrain concept, plasma surface technology offers outstanding opportunities for the optimization of highly stressed tribological systems. For example, Triondur physical vapor deposition and plasma‐assisted chemical vapor deposition coating systems in the automotive industry, where they were initially used to prevent wear, have become an extremely valuable design element for increasing energy efficiency and CO2 savings through friction reduction. As a result, more than 150 million components coated with Triondur were delivered worldwide in 2018. Defossilization of the energy chain requires increased industrialization of components for electrolyzers and fuel cells, such as the metallic bipolar plates of galvanic cells. Here too, plasma surface technology will play a key role in meeting the high demands for the required electrochemical properties and quality standards. For CO2‐neutral and sustainable mobility, plasma surface technology will continue to be a key technology, regardless of the powertrain concept.
Hydrogen Generation from Water Splitting by 3H2O + Pd13 → 3H2 + Pd13O3 Reaction
Authors: Xie Wen‐Li , Yang Chuan‐Lu
Published: March 2022

The Pd clusters are widely concerned because of their outstanding catalytic capacity. Here such a candidate of Pd13 cluster with the icosahedron symmetry and multiple active sites is shown. The first‐principles calculations reveal that this cluster can maximally catalyze the water‐splitting reaction to generate three H2 from three H2O molecules. The geometrical structures of the reactants, transition states, and products are optimized, and their stabilities are confirmed by the frequency analysis. The intrinsic reaction coordinates are constructed to confirm the rationality of the reaction. Firstly, one H2O is adsorbed on atop sites of the Pd13 cluster and releases an H2 through a reaction of H2O@Pd13 → H2@[O+Pd13]. Then, the remained O+Pd13 cluster can continually split H2O and generate additional H2, and the obtained 2O+Pd13 cluster can also dissociate H2O to generate H2. However, it is found that the 3O+Pd13 cluster cannot continue the splitting reaction. It is also observed that the O+Pd13 cluster can adsorb two molecules at the same time and split them one by one. These findings support that the Pd13 cluster, O+Pd13, and 2O+Pd13 are promising candidates for efficient generation of H2 from H2O splitting reaction.
Daytime predictors of nocturnal hypercapnic hypoventilation in children with neuromuscular disorders
Authors: Frohlich Megan , Widger John , Thambipillay Ganesh , Teng Arthur , Farrar Michelle , Chuang Sandra
Published: March 2022

Objectives

To examine objective daytime predictors of nocturnal hypercapnic hypoventilation (NHH) and identify a forced vital capacity (FVC) z‐score cut off that predicts NHH using the 2012 Global Lung Function Initiative (GLI) reference equations in pediatric neuromuscular patients.

Design

Single‐centre retrospective medical record review.

Setting

Tertiary pediatric hospital in Australia.

Patients

Children (<18 years old) with a neuromuscular disorder (NMD) who had a diagnostic sleep study over a 5‐year period.

Results

Fifty children were included, median age 11.9 years (interquartile range [IQR]: 4.5–14.3). The majority of children had a diagnosis of Duchenne Muscular Dystrophy (32%). NHH was diagnosed in 18 children (36%). Multivariate logistic regression analysis performed for the entire cohort confirmed a statistically significant association between NHH and scoliosis (odds ratio [OR]: 3.3, p = 0.03), but not age (OR: 1.01, p = 0.26), body mass index z‐score (OR: 0.86, p = 0.26) or use of a wheelchair for mobility (OR: 1.25, p = 0.72). For the subset of 29 children who had spirometry testing (median age 12.9 years [IQR: 10.2–14.3]), FVC z‐score was the only statistically significant predictor of NHH (OR: 0.45, p = 0.02). NHH was predicted by an FVC z‐score <−3.24 (sensitivity 78%, specificity 73%), or FVC <60% predicted (sensitivity 78%, specificity 73%). There was a strong positive correlation between FVC and forced expiratory volume in 1 s z‐scores (rp = 0.98, p = 0.00) and FVC and peak expiratory flow  z‐scores (rp = 0.72, p = 0.00).

Conclusion

Children with a NMD and scoliosis or a lower FVC z‐score have increased odds of having NHH.
Numerical Analysis on Acceleration Process and Shock Initiation of Parylene C−Cu Flyer in Exploding Foil Initiator
Authors: Xu Cong , Liu Zhi‐gang
Published: March 2022

Parylene C flyer coated with copper film was often used to shock and initiate insensitive explosives in exploding foil initiator (EFI). However, there were few studies on the acceleration process of parylene C−Cu flyer and the shock initiation induced by parylene C−Cu flyer. In this paper, exploding bridge foil was treated as a kind of special explosive to launch parylene C−Cu flyer, and an instantaneous explosion model was established to describe the acceleration process mathematically. Then, two‐dimensional numerical simulations were carried out using ANSYS/AUTODYN software to analyse the flight history and morphology of parylene C−Cu flyer, as well as the effect of copper film on flyer velocity. Finally, shock initiation of parylene C−Cu flyer impacting ultrafine hexanitrostilbene (HNS‐IV) was also simulated, and the initiation threshold was determined by adjusting the flyer velocity at the collision moment. Compared with previous work, calculated results exhibit good agreement with the experimental data, that is addition of Cu film can indeed improve the shock pressure but leads to lower flyer velocity. For parylene C−Cu flyer with the thickness of 25 μm–3.6 μm, its flyer velocity drops to half of parylene C flyer under same operation conditions, and the initiation threshold that can initiate the HNS‐IV pellet is 2300 m/s. All the results demonstrate that the numerical approach will be useful for the optimization of parylene C−Cu flyer, even any kind of multi‐layer flyer.
Toward Addressing the Challenge to Predict the Heat Capacities of RDX and HMX Energetic Materials
Authors: Sorescu Dan C. , Larentzos James P. , Rice Betsy M. , Brennan John K.
Published: March 2022

Availability of heat capacity as a function of pressure and temperature is an essential prerequisite for development of a computational multiscale strategy capable to address the evolution of microstructure and energy release in advanced high energy density materials. In the case of 1,3,5‐trinitro‐1,3,5‐triazinane (RDX) and 1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocane (HMX) systems as two of the most studied energetic materials, there are substantial gaps in experimental data, with available heat capacities values distributed only in a region close to standard ambient conditions. In this study we demonstrate how these major experimental limitations can be addressed in the case of the RDX and HMX systems based on the combined use of classical and quantum mechanical calculations. We show that by considering ideal gas properties evaluated using quantum mechanical methods, and residual properties obtained from molecular simulations using fully flexible atomistic force field models, excellent agreement can be obtained for the predicted heat capacities to the most recent experimental values. An important advantage of the current computational methodology is that it allows evaluation of both constant‐volume and constant‐pressure heat capacities for a broad interval of temperatures and pressures, which encompasses solid and liquid phases conditions. In the case of the solid α and γ phases of RDX and the β phase of HMX, the predicted results follow closely both the available experimental data at standard ambient conditions and the results obtained using density functional theory calculations at high pressures, a regime where experimental data are not available. A perspective to expand the current methodology is also discussed.
Structure and function of an N‐acetyltransferase from the human pathogen Acinetobacter baumannii isolate BAL_212
Authors: Herkert Noah R. , Thoden James B. , Holden Hazel M.
Published: March 2022

Acinetobacter baumannii is a Gram‐negative bacterium commonly found in soil and water that can cause human infections of the blood, lungs, and urinary tract. Of particular concern is its prevalence in health‐care settings where it can survive on surfaces and shared equipment for extended periods of time. The capsular polysaccharide surrounding the organism is known to be the major contributor to virulence. The structure of the K57 capsular polysaccharide produced by A. baumannii isolate BAL_212 from Vietnam was recently shown to contain the rare sugar 4‐acetamido‐4,6‐dideoxy‐d‐glucose. Three enzymes are required for its biosynthesis, one of which is encoded by the gene H6W49_RS17300 and referred to as VioB, a putative N‐acetyltransferase. Here, we describe a combined structural and functional analysis of VioB. Kinetic analyses show that the enzyme does, indeed, function on dTDP‐4‐amino‐4,6‐dideoxy‐d‐glucose with a catalytic efficiency of 3.9 x 104 M−1 s−1 (±6000), albeit at a reduced value compared to similar enzymes. Three high‐resolution X‐ray structures of various enzyme/ligand complexes were determined to resolutions of 1.65 Å or better. One of these models represents an intermediate analogue of the tetrahedral transition state. Differences between the VioB structure and those determined for the N‐acetyltransferases from Campylobacter jejuni (PglD), Caulobacter crescentus (PerB), and Psychrobacter cryohalolentis (Pcryo_0637) are highlighted. Taken together, this investigation sheds new insight into the Type I sugar N‐acetyltransferases.
Impact of insecticide programs on pests, the predatory mite Phytoseiulus persimilis, and staked tomato profitability
Authors: Bilbo Tom R. , Owens David R. , Golec Julian R. , Walgenbach James F.
Published: March 2022

BACKGROUND

Various insecticides are available to manage diverse pest complexes in commercial vegetable production, but knowledge gaps exist regarding their overall performance in pest suppression, profitability, and compatibility with biological control. We conducted trials in staked tomatoes in western North Carolina in 2017–2018 to compare how different insecticide programs managed key pests and their interactions with Phytoseiulus persimilis Athias‐Henriot, a predator of the twospotted spider mite (TSSM, Tetranychus urticae Koch). Treatments compared no insecticides to broad‐spectrum (‘hard’) foliar applications, selective (‘soft’) foliar applications, and to chemigation of selective systemic insecticides. Treatment efficacy was based on pest control, net profitability, and Environmental Impact Quotient (EIQ) ratings comparing environmental and human health risks.

RESULTS

All programs similarly suppressed aphids, while flower thrips and flea beetle populations were low and unaffected by program. Only the ‘hard’ foliar program suppressed TSSM (including P. persimilis), which quickly rebounded. This program inhibited biological control, and eventual TSSM suppression was likely caused by P. persimilis immigrating from nearby plots. All programs were generally equivalent in reducing fruit damage. Net profits were similar among insecticide programs, which were significantly greater than in untreated plots. Yield and profit trends were similar both years, but impacted by record flooding in 2018.

CONCLUSION

Safer and more selective chemigation and ‘soft’ foliar programs were as effective and economical as the ‘hard’ foliar program, while also conserving biological control. These results support existing research demonstrating that improved insecticide use can be integrated with biological control for more profitable and environmentally sustainable vegetable production. © 2022 Society of Chemical Industry.