Strong third-order nonlinearity in amorphous silicon carbide waveguides.

Silicon carbide (SiC) photonic integrated platform has attracted significant research interest for on-chip optical applications, owing to its exceptional optical properties such as a broad transparency window, high refractive index, and strong nonlinearity. Among the various types of SiC, amorphous SiC (a-SiC) has particularly emerged as an accessible choice for forming thin-film SiC-on-insulator (SiCOI) stacks, demonstrating promising capabilities for wafer-scale photonic applications. In this work, we prepare three a-SiCOI samples using the plasma-enhanced chemical vapor deposition, with different refractive indices. We fabricate optical waveguides, conduct four-wave mixing measurements, and characterize the nonlinear refractive index in these samples. Our findings reveal that an increase in the refractive index of a-SiC leads to a corresponding increase in the nonlinear refractive index, which is comparable to that of silicon. Hence, a-SiC offers an approach to develop a SiC platform with a wider bandgap than that of silicon, minimizing two-photon absorption while also providing a higher refractive index and stronger nonlinearity compared to crystalline SiC.

Interaction between air pollutants and meteorological factors on pulmonary tuberculosis in northwest China: A case study of eight districts in Urumqi.

Meteorological factors and air pollutants are associated with the spread of pulmonary tuberculosis (PTB), but few studies have examined the effects of their interactions on PTB. Therefore, this study investigated the impact of meteorological factors and air pollutants and their interactions on the risk of PTB in Urumqi, a city with a high prevalence of PTB and a high level of air pollution. The number of new PTB cases in eight districts of Urumqi from 2014 to 2019 was collected, along with data on meteorological factors and air pollutants for the same period. A generalized additive model was applied to explore the effects of meteorological factors and air pollutants and their interactions on the risk of PTB incidence. Segmented linear regression was used to estimate the nonlinear characteristics of the impact of meteorological factors on PTB. During 2014-2019, a total of 14,402 new cases of PTB were reported in eight districts, with March to May being the months of high PTB incidence. The exposure-response curves for temperature (Temp), relative humidity (RH), wind speed (WS), air pressure (AP), and diurnal temperature difference (DTR) were generally inverted "U" shaped, with the corresponding threshold values of - 5.411 °C, 52.118%, 3.513 m/s, 1021.625 hPa, and 8.161 °C, respectively. The effects of air pollutants on PTB were linear and lagged. All air pollutants were positively associated with PTB, except for O3, which was not associated with PTB, and the ER values for the effects on PTB were as follows: 0.931 (0.255, 1.612) for PM2.5, 1.028 (0.301, 1.760) for PM10, 5.061 (0.387, 9.952) for SO2, 2.830 (0.512, 5.200) for NO2, and 5.789 (1.508, 10.251) for CO. Meteorological factors and air pollutants have an interactive effect on PTB. The risk of PTB incidence was higher when in high Temp-high air pollutant, high RH-high air pollutant, high WS-high air pollutant, lowAP-high air pollutant, and high DTR-high air pollutant. In conclusion, both meteorological and pollutant factors had an influence on PTB, and the influence on PTB may have an interaction.

A spacer design strategy for CRISPR-Cas12f1 with single-nucleotide polymorphism mutation resolution capability and its application in the mutations diagnosis of pathogens.

Infectious diseases remain a major global issue in public health. It is important to develop rapid, sensitive, and accurate diagnostic methods to detect pathogens and their mutations. Cas12f1 is an exceptionally compact RNA-guided nuclease and have the potential to fulfill the clinical needs. Based on the interaction between crRNA-SSDNA binary sequence and Cas12f1, here, we addressed the essential features that determine the recognition ability of CRISPR-Cas12f1 single-nucleotide polymorphism (SNP), such as the length of spacer region and the base pairing region that determines the trans-cleavage of ssDNA. A fine-tuning spacer design strategy is also proposed to enhance the SNP recognition capability of CRISPR-Cas12f1. The optimized spacer confers the Cas12f1 system a strong SNP identification capability for viral or bacterial drug-resistance mutations, with a specificity ratio ranging from 19.63 to 110.20 and an admirable sensitivity up to 100  copy/µL. Together, the spacer screening and CRISPR-Cas12f1 based SNP identification method, is sensitive and versatile, and will have a wide application prospect in pathogen DNA mutation diagnosis and other mutation profiling.

High-performance silicon carbide polarization beam splitting based on an asymmetric directional couplers for mode conversion.

Polarization manipulation and management are important for 4H-silicon carbide (SiC) integrated photonics, as 4H-SiC has material-based birefringent properties. In this Letter, we propose a low-birefringence polarization beam splitter (PBS) based on asymmetric directional coupler (ADC) mode converters with overall high performances. We numerically and experimentally demonstrate the ADC mode conversion based PBS on a 4H-SiC chip. The experimental results show that the device exhibits high transmittance of -0.6 dB and -1.3 dB for the transverse-electric (TE) and transverse-magnetic (TM) polarized light, respectively, and broad operational bandwidth over 130 nm. The polarization extinction ratio of >25 dB and >17 dB covering the whole C band for the TE and TM polarized light, respectively, and an ultra-large polarization extinction ratio of >32 dB for both polarizations at approximately 1560 nm are achieved.

Effectiveness of the booster dose of inactivated COVID-19 vaccine against Omicron BA.5 infection: a matched cohort study of adult close contacts.

BACKGROUND: Although COVID-19 vaccines and their booster regimens protect against symptomatic infections and severe outcomes, there is limited evidence about their protection against asymptomatic and symptomatic infections in real-world settings, particularly when considering that the majority of SARS-CoV-2 Omicron infections were asymptomatic. We aimed to assess the effectiveness of the booster dose of inactivated vaccines in mainland China, i.e., Sinopharm (BBIBP-CorV) and Sinovac (CoronaVac), against Omicron infection in an Omicron BA.5 seeded epidemic. METHODS: Based on an infection-naive but highly vaccinated population in Urumqi, China, the study cohort comprised all 37,628 adults who had a contact history with individuals having SARS-CoV-2 infections, i.e., close contacts, between August 1 and September 7, 2022. To actively detect SARS-CoV-2 infections, RT-PCR tests were performed by local authorities on a daily basis for all close contacts, and a testing-positive status was considered a laboratory-confirmed outcome. The cohort of close contacts was matched at a ratio of 1:5 with the fully vaccinated (i.e., 2 doses) and booster vaccinated groups (i.e., 3 doses) according to sex, age strata, calendar date, and contact settings. Multivariate conditional logistic regression models were adopted to estimate the marginal effectiveness of the booster dose against Omicron BA.5 infection after adjusting for confounding variables. Subgroup analyses were performed to assess vaccine effectiveness (VE) in different strata of sex, age, the time lag from the last vaccine dose to exposure, and the vaccination status of the source case. Kaplan-Meier curves were employed to visualize the follow-up process and testing outcomes among different subgroups of the matched cohort. FINDINGS: Before matching, 37,099 adult close contacts were eligible for cohort enrolment. After matching, the 2-dose and 3-dose groups included 3317 and 16,051 contacts, and the proportions with Omicron infections were 1.03% and 0.62% among contacts in the 2-dose and 3-dose groups, respectively. We estimated that the adjusted effectiveness of the inactivated booster vaccine versus 2 doses against Omicron infection was 35.5% (95% CI 2.0, 57.5). The booster dose provided a higher level of protection, with an effectiveness of 60.2% (95% CI 22.8, 79.5) for 15-180 days after vaccination, but this VE decreased to 35.0% (95% CI 2.8, 56.5) after 180 days. Evidence for the protection of the booster dose was detected among young adults aged 18-39 years, but was not detected for those aged 40 years or older. INTERPRETATION: The receipt of the inactivated vaccine booster dose was associated with a significantly lower Omicron infection risk, and our findings confirmed the vaccine effectiveness (VE) of booster doses against Omicron BA.5 variants. Given the rapid evolution of SARS-CoV-2, we highlight the importance of continuously monitoring the protective performance of vaccines against the genetic variants of SARS-CoV-2, regardless of existing vaccine coverage.

Job burnout and its impact on work ability in biosafety laboratory staff during the COVID-19 epidemic in Xinjiang.

BACKGROUND: The coronavirus disease 2019 (COVID-19) has increased the physical and psychological stress of medical workers. This study was designed to investigate the prevalence and risk factors of job burnout and its impact on work ability among Biosafety Laboratory (BSL) staffs during the COVID-19 epidemic in Xinjiang. METHODS: A total of 7911 qualified BSL staffs in Xinjiang were investigated by electronic questionnaires. The Maslach Burnout Inventory-General Survey (MBI-GS) was used for job burnout survey. Work Ability Index (WAI) was used for work ability survey. The prevalence and risk factors of job burnout in BSL staffs were analyzed through chi square test, t-test and one-way ANOVA. And then, the influence of demographic and job-related variables, i.e., confounding factors, were eliminated to the greatest extent by the propensity score analysis (PSA) method, to investigate the impact of job burnout on work ability in BSL staffs. RESULTS: A total of 67.6% BSL staffs experienced job burnout. There were significant differences in the detection rate of job burnout among demographic and job-related variables, including gender, age, ethnicity, education, working years, professional title, marital status, number of night shift per month and overall sleep condition (all P < 0.05). The detection rate of job burnout in female was higher than that in male. The detection rates of job burnout in 45-50 years old, Han ethnicity, education of postgraduate or above, 11-20 years of working, intermediate professional title, married, staff with many night shifts per month and poor overall sleep condition were higher than that of other groups. The average burnout scores of the Emotional Exhaustion (EE), Cynicism (CY), Reduced Personal Accomplishment (PA) scale were 10.00 ± 5.99, 4.64 ± 4.59 and 15.25 ± 8.16, respectively. Multiple logistic regression analysis showed that the three dimensions of job burnout, i.e., EE, CY, PE, were negatively correlated with work ability and significantly affected the work ability of BSL staffs (all P < 0.001). CONCLUSIONS: Our results suggest that the prevalence of job burnout is extremely common among BSL staffs. In addition, the work ability decreases with the increase of job burnout and the improvement of job burnout can enhance work ability among BSL staffs.

Association of occupational burnout and occupational exposure factors on psychological health among factory workers and miners: a propensity score analysis.

PURPOSE: This study is to explore the association of occupational burnout and occupational exposure factors on psychological health among factory workers and miners. METHODS: A total of 6130 factories workers and miners in Urumqi, China were included using a cluster sampling method. The occupational burnout and psychological health were investigates using the Chinese Maslach Burnout Inventory (CMBI) and the Symptom Check List-90 (SCL-90). The propensity score analysis (PSA) was used to eliminate the influence of individual characteristics, and 2164 pairs of participants on psychological healthy and unhealthy were matched. After PSA, the relationship between occupational burnout, occupational hazard exposure, and psychological health was evaluated. RESULTS: The results showed that asbestos dust (OR 1.65, CI 95% 1.35-2.02) and CMBI (OR 2.59, CI 95% 2.39-2.83) were risk factors affecting psychological health (P < 0.001). CONCLUSIONS: Measures need to be taken to ease occupational burnout among factories workers and miners, and strengthen personal protection to improve their psychological health.

Effects of Occupational Radiation Exposure on Job Stress and Job Burnout of Medical Staff in Xinjiang, China: A Cross-Sectional Study.

BACKGROUND Although the potential effects of long-term and low-dose radiation exposure on physical health have attracted considerable attention, few systematic evaluations have been reported regarding the mental health of occupational groups. This study sought to investigate the effects of occupational radiation exposure on job stress and job burnout of medical radiation staff. MATERIAL AND METHODS Using cluster random sampling, a total of 1573 medical radiation workers were initially selected from 10 hospitals in Xinjiang, China, and 1396 valid questionnaires were finally collected. Job stress and job burnout were assessed using the Effort-Reward Imbalance (ERI) questionnaire and the Chinese Maslach Burnout Inventory (CMBI), respectively. RESULTS The percentages of medical radiation staff experiencing job stress and job burnout were 53.08% and 63.32%, respectively. A statistically significant difference in job stress was observed in association with age, ethnicity, professional title, marital status, radiation work type, radiation working years, family history, hypertension, obesity, smoking, and drinking (P<0.05). A statistically significant difference in job burnout was observed in association with age, sex, ethnicity, professional title, educational level, marital status, job post, radiation work type, radiation working years, family history, hypertension, diabetes, and obesity (P<0.05). Female (odds ratio [OR]=0.75, 95% confidence interval [CI]: 0.58-0.98), senior professional title (OR=0.64, 95% CI: 0.43-0.96), and radiation work types of nuclear medicine (OR=0.15, 95% CI: 0.07-0.33) and radiotherapy (OR=0.54, 95% CI: 0.36-0.79) were protective factors, and job stress (OR=4.57, 95% CI: 3.55-5.91) was the risk factor for job burnout of medical radiation staff. CONCLUSIONS Medical radiation staff experience high levels of job stress and job burnout. The interventions of occupational physical examination, personal dose monitoring, occupational health education, and management optimization are recommended to relieve job stress and job burnout and enhance occupational health of medical radiation staff.

Occupational stress and psychological health impact on hypertension of miners in noisy environment in Wulumuqi, China: a case-control study.

BACKGROUND: Hypertension has been declared as a global public health crisis by the World Health Organization, because of its high prevalence. It affects the health of one billion people worldwide and is directly responsible for the deaths of more than 10 million people per year. The purpose of our research was to explore the influence of occupational stress and psychological health on hypertension of miners who work in a noisy environment and provide decision reference for relevant departments to keep miners' health. METHODS: A case-control study was carried out in this research. The study subjects were divided into case groups and control groups based on whether they had hypertension or not. Effort-Reward Imbalance questionnaire and Self-Reporting Inventory questionnaire were used to investigate the psychological health status and occupational stress of the target population. General information was balanced between case and control groups through propensity score matching method. After propensity score matching, a multifactorial analysis was used to explore the impact of occupational stress and psychological health on hypertension. RESULTS: According to the result of the multivariate analysis, psychological health was hazard to hypertension (t = 5.080, P<0.001) and occupational stress was not a direct risk factor for hypertension (t = 1.760, P = 0.080). The model was statistically significant (χ2 = 20.4, P<0.01). CONCLUSIONS: For miners working in the noisy environment, psychological status was a direct risk factor to hypertension, while occupational stress was an indirect factor.

Decay channels of gap plasmons in STM tunnel junctions.

We study the decay of gap plasmons localized between a scanning tunneling microscope tip and metal substrate, excited by inelastic tunneling electrons. The overall excited energy from the tunneling electrons is divided into two categories in the form of resistive dissipation and electromagnetic radiation, which together can further be separated into four diffierent channels, including SPP channel on the tip, SPP channel on the substrate, air mode channel and direct quenching channel. In this work, we study the enhancement factor, i.e. Purcell factor, of the STM tunnel junctions, which are mediated by the nearby metallic structures. We find that the gap plasmon mode is most likely to couple to the SPP channel on the tip, rather than the SPP channel on the substrate or the air mode. The direct quenching in the apex of tip also takes a considerable portion especially in high frequency region, the enhancement factor of direct quenching in the tip is much higher than the direct quenching in the substrate. We adopt four tips with diffierent apex radii, i.e., 1 nm, 5 nm, 10 nm, 20 nm. When the apex size is small, the frequency dependent enhancement factor from the SPPs contribution has a pronounced peak at 1.55 eV, however, as the radius increases, the peak of enhancement factor in the high frequency region appears, the 1.55 eV peak becomes less dominated. This phenomenon can be attributed to the change of tip shape, in the form of mode coupling. Our results also show a relationship between the direct quenching in the substrate and in the tip. With the larger radius of apex, the ratio of these two part of energy approaches 1, which indicate that the energy distribution of direct quenching is sensitive to the shape of the tip-substrate gap.

Whole Genome Sequence-Based Analyses of Drug Resistance Characteristics, Genetic Diversity, and Transmission Dynamics of Drug-Resistant Mycobacterium tuberculosis in Urumqi City.

Objective: This study aims to analyze the drug resistance spectrum, genetic diversity, and transmission dynamics to provide a basis for the prevention and control of drug-resistant (DR) tuberculosis (TB) epidemics. Methods: This retrospective study is based on routine national drug resistance surveillance. The demographic, epidemiological, and clinical information on DR-TB patients from 2016 to 2021 was collected and used for phenotypic drug susceptibility testing and whole-genome sequencing. Results: It was indicated that L2.2.1 was the dominant lineage in Urumqi. The drug resistance spectrum in Urumqi was narrow, which means more drug combinations can be used for clinical treatment. Furthermore, mutations identification of drug-resistance gene katG, rpoB, embA/B, rrs, rpsL, eis, gyrA/B, folC and tryA are important for clinical drug use. However, mutations in cross-resistance genes rrs have limited guidance for clinical selection of KM, CPM and AK. Moreover, there is an increased risk of cluster transmission of DR-TB, and the difference in clustering rate among L2, L3, and L4 was not statistically significant (χ2 = 2.6410, p = 0.2670). Conclusion: In the Urumqi, DR-TB has a complex prevalence state, a narrow drug resistance spectrum, and a high clustering rate and burden of drug resistance. To reduce the burden of DR-TB, related research should be strengthened, and the development of prevention, control, and treatment strategies should be accelerated.

Efficient Raman Lasing and Raman-Kerr Interaction in an Integrated Silicon Carbide Platform.

Implementing stimulated Raman scattering in a low-loss microresonator could lead to Raman lasing. Here, we report the demonstration of an efficient Raman laser with >50% power efficiency in an integrated silicon carbide platform for the first time. By fine-tuning the free spectral range (FSR) of 43 µm-radius silicon carbide microresonators, the Stokes resonance corresponding to the dominant Raman shift of 777 cm-1 (23.3 THz) is aligned to the center of the Raman gain spectrum, resulting in a low power threshold of 2.5 mW. The peak Raman gain coefficient is estimated to be (0.75 ± 0.15) cm/GW in the 1550 nm band, with an approximate full width at half-maximum of (120 ± 30) GHz. In addition, the microresonator is designed to exhibit normal dispersion at the pump wavelength near 1550 nm while possessing anomalous dispersion at the first Stokes near 1760 nm. At high enough input powers, a Kerr microcomb is generated by the Stokes signal acting as the secondary pump, which then mixes with the pump laser through four-wave mixing to attain a wider spectral coverage. Furthermore, cascaded Raman lasing and the occurrence of multiple Raman shifts, including 204 cm-1 (6.1 THz) and 266 cm-1 (8.0 THz) transitions, are also observed. Finally, we show that the Stokes Raman could also help broaden the spectrum in a Kerr microcomb which has anomalous dispersion at the pump wavelength. Our example of a 100 GHz-FSR microcomb has a wavelength span from 1200 to 1900 nm with 300 mW on-chip power.

Transmission risks of Omicron BA.5 following inactivated COVID-19 vaccines among children and adolescents in China.

BACKGROUND: As SARS-CoV-2 Omicron variants circulating globally since 2022, assessing the transmission characteristics, and the protection of vaccines against emerging Omicron variants among children and adolescents are needed for guiding the control and vaccination policies. METHODS: We conducted a retrospective cohort study for SARS-CoV-2 infections and close contacts aged <18 years from an outbreak seeded by Omicron BA.5 variants. The secondary attack rate (SAR) was calculated and the protective effects of two doses of inactivated vaccine (mainly Sinopharm /BBIBP-CorV) within a year versus one dose or two doses above a year after vaccination against the transmission and infection of Omicron BA.5 were estimated. RESULTS: A total of 3442 all-age close contacts of 122 confirmed SARS-CoV-2 infections aged 0-17 years were included. The SAR was higher in the household setting and for individuals who received a one-dose inactivated vaccine or those who received a two-dose for more than one year, with estimates of 28.5% (95% credible interval [CrI]: 21.1, 37.7) and 55.3% (95% CrI: 24.4, 84.8), respectively. The second dose of inactivated vaccine conferred substantial protection against all infection and transmission of Omicron BA.5 variants within a year. CONCLUSIONS: Our findings support the rollout of the second dose of inactivated vaccine for children and adolescents during the Omciron BA.5 predominant epidemic phase. Given the continuous emergence of SARS-CoV-2 variants, monitoring the transmission risk and corresponding vaccine effectiveness against SARS-CoV-2 variants among children and adolescents is important to inform control strategy.

Children and adolescents have reported suffering less severe outcomes from the SARS-CoV-2 Omicron variant. However, the risk of transmission and vaccine effectiveness among this population group is not well studied. Here, we used contact tracing data that was collected during an Omicron BA.5 outbreak from Urumqi, China, before the exit of "zero-COVID" measures, to evaluate the spread of SARS-CoV-2 infection among those age under 18 years, and the effectiveness of inactivated vaccine regimens. Our findings indicate there is a high rate of transmission among children and adolescents in a household setting and receiving two doses of inactivated COVID-19 vaccination within a year was more effective than a single dose or two doses given more than a year apart. These findings highlight the importance of tracking transmission and vaccine effectiveness of novel SARS-CoV-2 variants in younger populations to inform control strategies.

Investigating the impact of extreme weather events and related indicators on cardiometabolic multimorbidity.

BACKGROUND: The impact of weather on human health has been proven, but the impact of extreme weather events on cardiometabolic multimorbidity (CMM) needs to be urgently explored. OBJECTIVES: Investigating the impact of extreme temperature, relative humidity (RH), and laboratory testing parameters at admission on adverse events in CMM hospitalizations. DESIGNS: Time-stratified case-crossover design. METHODS: A distributional lag nonlinear model with a time-stratified case-crossover design was used to explore the nonlinear lagged association between environmental factors and CMM. Subsequently, unbalanced data were processed by 1:2 propensity score matching (PSM) and conditional logistic regression was employed to analyze the association between laboratory indicators and unplanned readmissions for CMM. Finally, the previously identified environmental factors and relevant laboratory indicators were incorporated into different machine learning models to predict the risk of unplanned readmission for CMM. RESULTS: There are nonlinear associations and hysteresis effects between temperature, RH and hospital admissions for a variety of CMM. In addition, the risk of admission is higher under low temperature and high RH conditions with the addition of particulate matter (PM, PM2.5 and PM10) and O3_8h. The risk is greater for females and adults aged 65 and older. Compared with first quartile (Q1), the fourth quartile (Q4) had a higher association between serum calcium (HR = 1.3632, 95% CI: 1.0732 ~ 1.7334), serum creatinine (HR = 1.7987, 95% CI: 1.3528 ~ 2.3958), fasting plasma glucose (HR = 1.2579, 95% CI: 1.0839 ~ 1.4770), aspartate aminotransferase/ alanine aminotransferase ratio (HR = 2.3131, 95% CI: 1.9844 ~ 2.6418), alanine aminotransferase (HR = 1.7687, 95% CI: 1.2388 ~ 2.2986), and gamma-glutamyltransferase (HR = 1.4951, 95% CI: 1.2551 ~ 1.7351) were independently and positively associated with unplanned readmission for CMM. However, serum total bilirubin and High-Density Lipoprotein (HDL) showed negative correlations. After incorporating environmental factors and their lagged terms, eXtreme Gradient Boosting (XGBoost) demonstrated a more prominent predictive performance for unplanned readmission of CMM patients, with an average area under the receiver operating characteristic curve (AUC) of 0.767 (95% CI:0.7486 ~ 0.7854). CONCLUSIONS: Extreme cold or wet weather is linked to worsened adverse health effects in female patients with CMM and in individuals aged 65 years and older. Moreover, meteorologic factors and environmental pollutants may elevate the likelihood of unplanned readmissions for CMM.

3D porous N-doped lignosulfonate/graphene oxide aerogel for efficient solar steam generation and desalination.

Solar-driven interfacial evaporation has been considered one of the most promising approaches to tackle the issue of water scarcity. The salt resistance and water transport capacity of solar evaporation materials are essential to evaluate desalination performance. Herein, a 3D-porous N-doped lignosulfonate/graphene oxide (GO) aerogel (NLGA) was facilely prepared by a one-step hydrothermal method. By introducing ethylenediamine (EDA) as a nitrogen source, the wettability and water transport capacity of the aerogel were enhanced; by introducing lignosulfonate (LS), its porous structure was regulated, and its light absorption capability was significantly improved. The obtained aerogel exhibited an outstanding evaporation rate (1.57 kg m-2 h-1) and efficiency (95.2 %) under 1 sun illumination, which is significantly better than some reported foam-based solar evaporators. In addition, NLGA maintained a stable evaporation rate over long-term cyclic evaporation without visible salt accumulation on the surface. The good salt rejection performance is due to the rich-pore structure and superhydrophilicity of NGLA, which provides sufficient water supply to dissolve the salts during water evaporation. NLGA has enormous potential as a solar evaporator based on its excellent performance in solar vapor generation.

Wet-Oxidation-Assisted Chemical Mechanical Polishing and High-Temperature Thermal Annealing for Low-Loss 4H-SiC Integrated Photonic Devices.

Silicon carbide (SiC) has become a promising optical material for quantum photonics and nonlinear photonics during the past decade. In this work, we propose two methods to improve the 4H-SiC thin film quality for SiC integrated photonic chips. Firstly, we develop a wet-oxidation-assisted chemical mechanical polishing (CMP) process for 4H-SiC, which can significantly decrease the surface roughness from 3.67 nm to 0.15 nm, thus mitigating the light scattering loss. Secondly, we find that the thermal annealing of the 4H-SiC devices at 1300 °C can help to decrease the material absorption loss. We experimentally demonstrate that the wet-oxidation-assisted CMP and the high-temperature annealing can effectively increase the intrinsic quality factor of the 4H-SiC optical microring resonators.

Lignin microparticles-reinforced cellulose filter paper for simultaneous removal of emulsified oils and dyes.

The presence of multiple pollutants in wastewater, often with complex interactions, poses a significant challenge for conventional membranes to effectively remove multiple pollutants simultaneously. Herein, a lignin microparticles-reinforced cellulose filter paper (FP@AL-LS-DA) was fabricated via an aldol condensation between lignin and cellulose filter paper and cross-linking with dopamine hydrochloride (DA), which showed desired rejection of oil-in-water emulsions and dyes. Characterizations revealed that the addition of lignin and DA effectively narrowed the pore size (from 4.45 µm to 2.01 µm) and enhanced the rigidity and stability of the cellulose filter paper, thus making it not easily damaged in the water environment and showing excellent tolerance to strong acid and high-salt environments. The oil-in-water emulsions removal efficiency was higher than 99 % even after ten times usage, and the oil flux was kept stable at 52.54 L·m-2·h-1, indicating that FP@AL-LS-DA had outstanding reusability and stability. Remarkably, FP@AL-LS-DA showed excellent removal efficiency (>99 %) for complex pollutants containing dyes and oil-in-water emulsions. In this work, we demonstrate a lignin microparticles-reinforced cellulose filter paper that is simple to prepare and can efficiently separate oil-in-water emulsions and remove dyes.

In situ doping lignin-derived carbon quantum dots on magnetic hydrotalcite for enhanced degradation of Congo Red over a wide pH range and simultaneous removal of heavy metal ions.

A new N, S-CQDs@Fe3O4@HTC composite was prepared by loading N, S carbon quantum dots (N, S-CQDs) derived from lignin on magnetic hydrotalcite (HTC) via an in-situ growth method. The characterization results showed that the catalyst had a mesoporous structure. These pores facilitate the diffusion and mass transfer of pollutant molecules inside the catalyst, allowing them to approach the active site smoothly. The catalyst performed well in the UV degradation of Congo red (CR) over a wide pH range (3-11), with efficiencies over 95.43 % in all cases. Even at a high NaCl content (100 g/L), the catalyst showed extraordinary CR degradation (99.30 %). ESR analysis and free radical quenching experiments demonstrated that OH and O2- were the main active species governing CR degradation. Besides, the composite had outstanding removal efficiency for Cu2+ (99.90 %) and Cd2+ (85.08 %) simultaneously due to the electrostatic attraction between the HTC and metal ions. Moreover, the N, S-CQDs@Fe3O4@HTC had excellent stability and recyclability during five cycles, making it free of secondary contamination. This work provides a new environment-friendly catalyst for the simultaneous removal of multiple pollutants and a waste-to-waste strategy for the value-added utilization of lignin.

Distinguishing the Vaccine Effectiveness of Inactivated BBIBP-CorV Vaccine Booster Against the Susceptibility, Infectiousness, and Transmission of Omicron Stains: A Retrospective Cohort Study in Urumqi, China.

INTRODUCTION: With COVID-19 vaccination rolled out globally, increasing numbers of studies have shown that booster vaccines can enhance an individual's protection against the infection, hospitalization, and death caused by SARS-CoV-2. This study evaluated the effectiveness of COVID-19 vaccine BBIBP-CorV booster against being infected (susceptibility), infecting others (infectiousness), and spreading the disease from one to another (transmission). METHODS: This retrospective cohort study investigated the close contacts of all officially ascertained COVID-19 confirmed cases in Urumqi, China between August 1 and September 7, 2022. Eligible records were divided into four subcohorts based on the vaccination status of both the close contact and their source case: group 2-2, 2-dose contacts seeded by 2-dose source case (as the reference level); group 2-3, 3-dose contacts seeded by 2-dose source case; group 3-2, 2-dose contacts seeded by 3-dose source case; and group 3-3, 3-dose contacts seeded by 3-dose source case. In the four subcohorts, multivariate logistic regression models were used to examine the vaccine effectiveness (VE) for the BBIBP-CorV booster dose. We adjusted for potential confounding variables, including the sex and age of source cases and close contacts, the calendar week of contact history and contact settings. We evaluated the statistical uncertainty using a 95% confidence interval (CI). In addition, we conducted subgroup analyses to evaluate VE by sex. RESULTS: The sample sizes of groups 2-2, 2-3, 3-2, and 3-3 were 1184, 3773, 4723, and 27,136 individuals, respectively. Overall VE against susceptibility (group 2-3 vs 2-2) was 42.1% (95% CI 10.6, 62.5), VE against infectiousness (group 3-2 vs 2-2) was 62.0% (95% CI 37.2, 77.0), and VE against transmission (group 3-3 vs 2-2) was 83.7% (95% CI 75.1, 89.4). In the sex-stratified subgroups, male close contacts showed similar VE compared to the overall. However, among female close contacts, while the booster dose improved VE against infectiousness and VE against susceptibility, the VEs were not significantly different from zero. CONCLUSION: BBIBP-CorV vaccine booster was associated with mild to moderate levels of protection against Omicron susceptibility, infectiousness, and transmission. Real-world assessment of protective performance of COVID-19 vaccines against the risk of Omicron strains is continuously needed, and may provide information that helps vaccination strategy.

Novel Photonic Applications of Silicon Carbide.

Silicon carbide (SiC) is emerging rapidly in novel photonic applications thanks to its unique photonic properties facilitated by the advances of nanotechnologies such as nanofabrication and nanofilm transfer. This review paper will start with the introduction of exceptional optical properties of silicon carbide. Then, a key structure, i.e., silicon carbide on insulator stack (SiCOI), is discussed which lays solid fundament for tight light confinement and strong light-SiC interaction in high quality factor and low volume optical cavities. As examples, microring resonator, microdisk and photonic crystal cavities are summarized in terms of quality (Q) factor, volume and polytypes. A main challenge for SiC photonic application is complementary metal-oxide-semiconductor (CMOS) compatibility and low-loss material growth. The state-of-the-art SiC with different polytypes and growth methods are reviewed and a roadmap for the loss reduction is predicted for photonic applications. Combining the fact that SiC possesses many different color centers with the SiCOI platform, SiC is also deemed to be a very competitive platform for future quantum photonic integrated circuit applications. Its perspectives and potential impacts are included at the end of this review paper.