Search

【Objective】In order to solve the problem of the limited bandwidth of polarization insensitive optical power splitter, an ultra-broadband polarization insensitive optical power splitter based on Silicon Nitride (Si3N4) waveguide is proposed.【Methods】The ultra-broadband polarization insensitive optical power splitter is designed based on adiabatic coupling Si3N4 waveguide.Optical bandwidth of 300 nm (from 1 400 ~ 1 700 nm) is demonstrated for both Transverse Electric (TE) and Transverse Magnetic (TM) modes.【Results】Over the entire optical bandwidth, the losses for TE and TM mode are less than 0.10 and 0.15 dB, respectively.The footprint of the proposed ultra-broadband polarization insensitive optical power splitter is only 60.00 μm×2.75 μm, which means that the optical power splitter can be used for large-scale integration.Furthermore, the relationship between the performance and the structure parameters of the proposed optical power splitter is studied.【Conclusions】The results show that the performance of the optical power splitter maintains almost unchanged by varying the structure parameters with ±50 nm.In other words, the optical power splitter possesses large fabrication tolerance which can be easily fabricated.

Background: Techniques for sperm cryopreservation have exhibited their potential in male fertility preservation. The use of frozen–thawed sperm in in vitro fertilization (IVF) cycles is widespread today. However, many studies reported that cryopreservation might have adverse effects on sperm DNA integrity, motility, and fertilization, probably due to cold shock, intra- and extracellular ice crystals, and excess reactive oxygen species (ROS). Studies suggested that freezing and thawing impaired sperm viability and might adversely affect subsequent fertilization and pregnancy outcomes. The potential damage to fertilization and subsequent embryonic development and offspring health raises the concern on sperm cryopreservation. However, the above mentioned studies are limited to intracytoplasmic sperm injection (ICSI) cycles, while IVF is a more natural and patient-friendly method. IVF requires a higher quality of sperm than ICSI. However, the effect of freezing and thawing on sperm used for IVF remains unknown. Therefore, we aim to investigate the effect of freezing and thawing on ejaculated sperm and subsequent pregnancy and neonatal outcomes in IVF. Methods: This retrospective cohort study at a tertiary-care academic medical center included 447 women who used paternal frozen–thawed ejaculated sperm and 31,039 women who used paternal freshly ejaculated sperm for IVF and underwent frozen–thawed blastocyst transfer from January 2011 to September 2021. To balance the baseline characteristics of the two groups, patients using frozen sperm were matched with control groups using a propensity score matching algorithm with a ratio of 1:3. Results: Although sperm motility decreased from 82.04% to 75.70% (P < 0.001) after the freezing–thawing process, the fertilization rate (68.27% for frozen sperm and 67.54% for fresh sperm), number of viable embryos (1.98 and 2.16), clinical pregnancy rate (44.7% and 51.8%), and live birth rate (40.3% and 42.4%) were comparable between the two groups (all P > 0.05). For neonatal outcomes, no between-group differences were observed in offspring gender, gestational age, birthweight, and the rate of preterm birth (21.7% and 12.9%), low birthweight neonates (19.2% and 16.0%), and birth defects (0.0% and 0.8%) (all P>0.05). Conclusions: Frozen–thawed sperm had lower sperm motility but resulted in comparable embryonic, pregnancy, and neonatal outcomes versus fresh sperm in IVF cycles. [ABSTRACT FROM AUTHOR]

Constructing mixed-metal nodes and heterojunctions in UiO-66-NH2 (UNH) are two effective strategies to improve the photocatalytic activity and CH4 selectivity in CO2 photoreduction. In this study, ZnO-loaded CeO2 (CeO2/ZnO) was added to the solvothermal synthesis system of UNH, in order to introduce Zn2+ and nano-CeO2 simultaneously into the UNH framework. The XRD, SEM, FT-IR and XPS characterization results proved that Zn2+ partially replaced Zr4+ to form mixed-metal nodes, and the nano-CeO2 was encapsulated in the UNH framework. The optimal catalyst exhibited a CO yield of 22.52 μmol g−1 h−1 and a CH4 yield of 53.18 μmol g−1 h−1 with a CH4 selectivity of 90.42%. The photoelectrochemical characterization and ESR radical trapping experiment results confirmed that Zn-doped UNH was conducive to the enhancement of light utilization, and the direct Z-scheme heterojunction which was constructed between Zn-doped UNH and CeO2 facilitated the separation and migration of photogenerated carriers. The in situ DRIFTS results indicated that the reaction mechanism of CO2 on the catalyst followed the formaldehyde pathway, and the *HCOO species was the key intermediate for CH4 generation. [ABSTRACT FROM AUTHOR]

Polygoni Multiflori Radix (PMR) is a medicinal herb commonly used in China and Eastern Asia. Recently, the discovery of hepatotoxicity in PMR has received considerable attention from scientists. Processing is a traditional Chinese medicine technique used for the effective reduction of toxicity. One uncommon technique is the braising method—also known as 'Wen‐Fa' in Chinese—which is used to prepare tonics or poisonous medications. Braised PMR (BPMR)—also known as 'Wen‐He‐Shou‐Wu'—is one of the processed products of the braising method. However, the non‐volatile components of BPMR have not been identified and examined in detail, and therefore, the hepatotoxic advantage of BPMR remains unknown. In this study, we compared the microscopic characteristics of different samples in powder form using scanning electron microscopy (SEM), investigated the non‐volatile components, assessed the effects of different processed PMR products on the liver, and compared the differences between BPMR and PMR Praeparata recorded in the Chinese Pharmacopoeia (2020 edition). We found that the hepatotoxicity of BPMR was dramatically decreased, which may be related to an increase in polysaccharide content and a decrease in toxic substances. The present study provides an important foundation for future investigations of the processing mechanisms of BPMR. [ABSTRACT FROM AUTHOR]

STUDY QUESTION What are the odds of achieving pregnancy when adopting progestin-primed ovarian stimulation (PPOS)-related protocols combined with repetitive frozen-thawed transfer (FET) cycles in patients with different clinical characteristics? SUMMARY ANSWER The cumulative live birth rates (CLBRs) of women undergoing different PPOS-related protocols can be significantly and consistently enhanced within six FET cycles when the female age is <40 years (or even <45 years) and when >5 oocytes are retrieved, regardless of antral follicle count (AFC). WHAT IS KNOWN ALREADY There have been numerous studies on the live birth rate of the first FET cycle in patients with PPOS-related protocols. These studies have focused mainly on comparing pregnancy outcomes with those of other stimulation protocols. However, owing to the unique features of the PPOS-related strategy, such as its flexible timing of oocyte retrieval and repeated transfer of frozen embryos, studies using the CLBR as an overall indicator of success and investigating which types of patients would benefit from this protocol are lacking. STUDY DESIGN, SIZE, DURATION This retrospective cohort study included 18 593 women who underwent PPOS-related protocols (dydrogesterone + hMG, medroxyprogesterone acetate + hMG, micronized progesterone + hMG treatment, and luteal-phase ovarian stimulation protocol) from 1 March 2011 to 31 September 2022 in our centre. PARTICIPANTS/MATERIALS, SETTING, METHODS The population was categorized by female age, number of oocytes retrieved, and AFC in the analysis of CLBR within six FET cycles. The age groups (Groups 1–5, respectively) were <30, 30–34, 35–39, 40–44, and ≥45 years. The number of oocytes retrieved was grouped as 1–5, 6–10, 11–15, 16–20, and >20. AFC was grouped as <5, 5–10, 11–15, and >15. The Kaplan–Meier analysis (optimistic method), which hypothesized that patients who did not continue treatment had the same chance of achieving a live birth as those who continued, and the competing risk method (conservative method) which hypothesized they had no chance of achieving a live birth, were applied. In further analyses, the Cox model and Fine–Gray model were adopted: the former corresponds to the optimistic scenario, and the latter corresponds to the pessimistic scenario. MAIN RESULTS AND THE ROLE OF CHANCE CLBR had a declining trend with female age over six FET cycles (Groups 1–5, respectively: optimistic: 96.9%, 96.6%, 91.4%, 67.3%, and 11.7%; conservative: 87.3%, 85.0%, 74.0%, 41.3%, and 7.5%), requiring more FET cycles to achieve a success rate of at least 50% (Groups 1–5, respectively: optimistic: 2, 2, 2, 4, and >6 cycles; conservative: 2, 2, 2, >,6 and >6 cycles). CLBR showed an increasing trend with the number of oocytes retrieved (Groups 1–5, respectively: optimistic: 93.8%, 94.3%, 95.8%, 96.0%, and 95.6%; conservative: 66.2%, 78.3%, 85.6%, 88.9%, and 91.0%). All groups needed the same number of FET cycles to achieve a success rate of at least 50% (Groups 1–5, respectively: optimistic: 2, 2, 2, 2, and 2 cycles; conservative: 2, 2, 2, 2, and 2 cycles). Furthermore, the CLBR within six FET cycles had an increasing trend with AFC number (Groups 1–4, respectively: optimistic: 89.2%, 94.8%, 95.9%, and 96.3%; conservative: 67.4%, 78.2%, 83.9%, and 88.1%), with all four groups achieving a success rate of at least 50% by the second FET cycle. LIMITATIONS, REASONS FOR CAUTION The current research is limited by its retrospective design and single-centre nature, which may restrict the generalizability of our findings. WIDER IMPLICATIONS OF THE FINDINGS This work describes two models (the Kaplan–Meier analysis and the competing risk method) to evaluate the clinical outcome of patients using PPOS-related protocols, which are especially useful for patients of advanced age or those with diminished ovarian reserve. Our findings encourage patients below 45 years old, especially younger than 40 years, and patients with lower AFCs and fewer retrieved oocytes to try this new protocol. Moreover, this study demonstrates the degree of improvement in the CLBR within six FET cycles for patients with different clinical characteristics, providing a valuable point of reference to determine whether to continue ART after a transfer failure. STUDY FUNDING/COMPETING INTEREST(S) The study was supported by grants from the National Natural Science Foundation of China (82071603 to L.W. 82001502 to Y.L.). There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

Mercury pollution in the atmospheric environment is a matter of international concern. Mercury in coal-fired flue gas is the first human mercury emission source and has become the focus of national mercury pollution control. The catalytic performance of zerovalent mercury (Hg0) in coal-fired flue gas was studied by using manganese-cerium-aluminum oxide as catalyst. The effects of metal loading ratio, reaction temperature, calcination temperature, and O2 and SO2 concentration on the efficiency of Hg0 catalytic removal were investigated, and the Mn-Ce/γ-Al2O3 catalysts before and after the reaction were characterized by BET, SEM, XRD, and XPS to analyze the physicochemical properties of the samples. The results show that the mercury removal efficiency of the composite catalyst with Mn, Ce, and Al as the active component is higher than that of the single metal catalyst. The catalytic activity of Mn0.1Ce0.02Al is the best, the optimum reaction temperature is 150°C, the optimum calcination temperature is 400°C, and the O2 concentration in the conventional flue gas condition satisfies the effective oxidation of Hg0; SO2 in the flue gas can seriously inhibit the oxidation of Hg0. [ABSTRACT FROM AUTHOR]