During its transition to a market economy, structural inequalities became increasingly apparent across China’s workforce, threatening social harmony. China’s 2008 Employment Contract Law, legislated amid policy debate, was intended to remedy these phenomena. We examine a crucial element of its remit: has its promotion of continuing contracts as against fixed-term employment contracts been effective? This is crucial for improving workers’ rights through secure employment. How have employers responded to this challenge to their prerogatives in terms of hiring and firing? We analysed data from 2007 and 2012 drawn from All-China Federation of Trade Unions surveys, which cover approximately 80,000 individuals. Using institutional theory, we discuss a variety of employer responses. We find that the Employment Contract Law has increased the likelihood of signing continuing contracts among migrant workers, employees in privately owned enterprises, and those with lower professional titles and who are short-term employees – all disadvantaged labour market categories previously. It has also significantly narrowed gaps regarding access to continuing contracts between these categories and matched advantaged ones. There is also evidence that some employers seek to avoid or sidestep compliance through cost-minimising worker engagement strategies.

In this paper, a frequency selective surface (FSS) based shared-aperture antenna is designed for 5G/Wi-Fi applications. The 5G and Wi-Fi channel are separated to achieve different polarizations and simultaneous work. The proposed antenna is of ±45°-polarization in the 5G N79 band and vertical polarization in the Wi-Fi5.8 GHz band. The antenna is vertically stacked with the N79 band antenna located above the Wi-Fi band antenna. The N79 antenna is composed of FSS units with transmissive characteristics in the Wi-Fi band, and serves as an electromagnetically transparent surface to avoid blocking the Wi-Fi antenna. A prototype of our design is fabricated, assembled and tested, and measured results show that the prototype is able to cover the entire N79 band (4.1–5.2 GHz, 23.7%) and Wi-Fi5.8 GHz band (5.73–5.89 GHz, 2.8%). Measured average gain is 8.2 and 7.8 dBi in the N79 and Wi-Fi band, respectively, and radiation efficiency is over 86 and 80%. The proposed design exhibits separated channels, tri-polarizations, high gain and compact size, which is sufficient for regular 5G/Wi-Fi applications. The antenna also achieves a relatively wide and highly consistent signal coverage in the two bands, making it suitable for 5G/Wi-Fi multi-function communication and indoor 5G blind compensation.

This research communication investigated the role and the underlying mechanism of sn-1-acylglycerol-3-phosphate O-acyltransferase 6 (AGPAT6) in acetate-induced mTORC1 signaling activation and milk fat synthesis in dairy cow mammary epithelial cells. The data showed AGPAT6 knockdown significantly decreased acetate-induced phosphorylation of mTORC1 signaling molecules and intracellular triacylglycerol (TAG) content, whereas this inhibition effect was reversed after the addition of 16:0,18:1 phosphatidic acid (PA), suggesting that AGPAT6 could generate PA in response to acetate simulation, that in turn activates mTORC1 signaling. PPARγ is the upstream regulator of AGPAT6 upon acetate stimulation. Luciferase assay with clones containing various deletions and mutation in AGPAT6 promoter showed that there is a RXRα binding sequence located at −96 bp of AGPAT6 promoter. Acetate stimulation significantly increased the interaction between PPARγ and AGPAT6 via this RXRα binding site. Taken together, our data indicated that AGPAT6 could activate mTORC1 signaling by producing PA during acetate-induced milk fat synthesis, and PPARγ acts as a transcription factor to mediate the effect of acetate on AGPAT6 via RXRα.

In the treatment of infertile patients with non-obstructive azoospermia (NOA) caused by the deletion of the azoospermia factor c region (AZFc) on the Y chromosome, synchronous and asynchronous surgical strategies are discussed. Clinical data from NOA patients with the AZFc deletion who underwent micro-TESE were analyzed retrospectively. The sperm retrieval rate (SRR) and sperm utilization rate of synchronous and asynchronous operation groups were followed up and compared. The fertilization rate, high-quality embryo rate, clinical pregnancy rate, abortion rate, and cumulative live birth rate of ICSI in patients with successful sperm retrieval were compared between the two groups. The two groups had sperm utilization rates of 98.9% (93/94) and 50.0% (14/28), respectively. The asynchronous group’s sperm consumption rates were much lower than those of the synchronous operation group. Fertilization rate, high-quality embryo rate, clinical pregnancy rate of fresh transfer cycle, abortion rate, and cumulative live birth rate of patients in the synchronous operation group with fresh sperm, and the asynchronous operation group with thawed sperm, respectively, were 30.6% vs 33.8%, 33.8% vs 40.7%, 40.0% vs 12.5%, 30.4% vs 7.1%. Between the two groups, there was no significant difference. This suggests that individuals with NOA caused by the AZFc deletion have a high possibility of successfully acquiring sperm using micro-TESE and ICSI to conceive their own offspring. Synchronous micro-TESE is recommended to improve sperm utilization rate and the cumulative live birth rate.

Maternal gestational weight gain (GWG) is an important determinant of infant birth weight, and having adequate total GWG has been widely recommended. However, the association of timing of GWG with birth weight remains controversial. We aimed to evaluate this association, especially among women with adequate total GWG. In a prospective cohort study, pregnant women’s weight was routinely measured during pregnancy, and their GWG was calculated for the ten intervals: the first 13, 14–18, 19–23, 24–28, 29–30, 31–32, 33–34, 35–36, 37–38 and 39–40 weeks. Birth weight was measured, and small-for-gestational-age (SGA) and large-for-gestational-age were assessed. Generalized linear and Poisson models were used to evaluate the associations of GWG with birth weight and its outcomes after multivariate adjustment, respectively. Of the 5049 women, increased GWG in the first 30 weeks was associated with increased birth weight for male infants, and increased GWG in the first 28 weeks was associated with increased birth weight for females. Among 1713 women with adequate total GWG, increased GWG percent between 14 and 23 weeks was associated with increased birth weight. Moreover, inadequate GWG between 14 and 23 weeks, compared with the adequate GWG, was associated with an increased risk of SGA (43 (13·7 %) v. 42 (7·2 %); relative risk 1·83, 95 % CI 1·21, 2·76). Timing of GWG may influence infant birth weight differentially, and women with inadequate GWG between 14 and 23 weeks may be at higher risk of delivering SGA infants, despite having adequate total GWG.

Hyperhomocysteinaemia (HHcy) is associated with all-cause mortality in some disease states. However, the correlation between HHcy and the risk of mortality in the general population has rarely been researched. We aimed to evaluate the association between HHcy and all-cause and cause-specific mortality among adults in the USA. This study analysed data from the National Health and Nutrition Examination Survey database (1999–2002 survey cycle). A multivariable Cox regression model was built to evaluate the correlation between HHcy and all-cause and cause-specific mortality. Smooth curve fitting was used to analyse their dose-dependent relationship. A total of 8442 adults aged 18–70 years were included in this study. After a median follow-up period of 14·7 years, 1007 (11·9 %) deaths occurred including 197 CVD-related deaths, 255 cancer-related deaths and fifty-eight respiratory disease deaths. The participants with HHcy had a 93 % increased risk of all-cause mortality (hazard ratio (HR) 1·93; 95 % CI (1·48, 2·51)), 160 % increased risk of CVD mortality (HR 2·60; 95 % CI (1·52, 4·45)) and 82 % increased risk of cancer mortality (HR 1·82; 95 % CI (1·03, 3·21)) compared with those without HHcy. For unmeasured confounding, E-value analysis proved to be robust. In conclusion, HHcy was associated with high risk of all-cause and cause-specific (CVD, cancer) mortality among adults aged below 70 years.

Dynamics of two-dimensional flow past a rigid flat plate with a trailing closed flexible filament acting as a deformable afterbody are investigated numerically by an immersed boundary-lattice Boltzmann method for the fluid flow and a finite element method for the filament motion. The effects of Reynolds number ($Re$) and length ratio ($Lr$) on the flow patterns and dynamics of the rigid-flexible coupling system are studied. Based on our numerical results, five typical state modes have been identified in $Lr\unicode{x2013}Re$ plane in terms of the filament shape and corresponding dynamics, i.e. static deformation, micro-vibration, multi-frequency flapping, periodic flapping and chaotic flapping modes, respectively. Benefiting from the passive flow control by using the flexible filament as a deformable afterbody, the coupled system may enjoy a significant drag reduction (up to $22\,\%$) compared with bare plate scenarios ($Lr=1$). Maximum drag reduction achieved at $L_{c,{min}} \in [1.8, 2]$ is often accompanied by the onset of the system state transition. The flow characteristic and its relation to the change in hydrodynamic drag are further explored in order to reveal the underlying mechanisms of the counterintuitive dynamical behaviour of the coupled system. The scaling laws for the form drag and the friction drag, which arise from the pressure and viscous effects, respectively, are proposed to estimate the overall drag acting on the system. The results obtained in the present study may shed some light on understanding the dynamical behaviour of rigid-flexible coupling systems.

N-acetylcysteine (NAC) possesses a strong capability to ameliorate high-fat diet (HFD)-induced non-alcoholic fatty liver disease (NAFLD) in mice, but the underlying mechanism is still unknown. Our study aimed to clarify the involvement of long non-coding RNA (lncRNA) in the beneficial effects of NAC on HFD-induced NAFLD. C57BL/6J mice were fed a normal-fat diet (10 % fat), a HFD (45 % fat) or a HFD plus NAC (2 g/l). After 14-week of intervention, NAC rescued the deleterious alterations induced by HFD, including the changes in body and liver weights, hepatic TAG, plasma alanine aminotransferase, plasma aspartate transaminase and liver histomorphology (haematoxylin and eosin and Oil red O staining). Through whole-transcriptome sequencing, 52 167 (50 758 known and 1409 novel) hepatic lncRNA were detected. Our cross-comparison data revealed the expression of 175 lncRNA was changed by HFD but reversed by NAC. Five of those lncRNA, lncRNA-NONMMUT148902·1 (NO_902·1), lncRNA-XR_001781798·1 (XR_798·1), lncRNA-NONMMUT141720·1 (NO_720·1), lncRNA-XR_869907·1 (XR_907·1), and lncRNA-ENSMUST00000132181 (EN_181), were selected based on an absolute log2 fold change value of greater than 4, P-value < 0·01 and P-adjusted value < 0·01. Further qRT-PCR analysis showed the levels of lncRNA-NO_902·1, lncRNA-XR_798·1, and lncRNA-EN_181 were decreased by HFD but restored by NAC, consistent with the RNA sequencing. Finally, we constructed a ceRNA network containing lncRNA-EN_181, 3 miRNA, and 13 mRNA, which was associated with the NAC-ameliorated NAFLD. Overall, lncRNA-EN_181 might be a potential target in NAC-ameliorated NAFLD. This finding enhanced our understanding of the biological mechanisms underlying the beneficial role of NAC.

Cap-shaped skeletal fossils are the earliest undisputed body fossils of mollusks appearing in the basal Cambrian. A study on the morphometry of cap-shaped fossils from the Nanjiang area (North Sichuan, China) is undertaken to understand the origin and evolution of the early mollusks. The distribution of these fossil cap-shaped mollusks indicates a stepwise increase in their diversity during the early Cambrian. Maikhanella Zhegallo in Voronin et al., 1982 co-occuring with the spinose sclerites of siphogonuchitids, is regarded as the earliest scleritized mollusk. It is followed by other maikhanellids, e.g., Purella Missarzhevsky, 1974 and Yunnanopleura Yu, 1987, which co-occur with the earliest univalved helcionellids, e.g., Igorella Missarzhevsky in Rozanov et al., 1969. Cluster analysis of their morphometric characteristics shows that the Maikhanella group is similar to the Purella and Yunnanopleura groups, but is less comparable with univalved helcionellids. The maikhanellids are interpreted as representatives of the stem group Aculifera, although it remains uncertain if one or two larger cap-shaped shell plates were present on the elongate slug-like body, comparable to those of Halkieria Poulsen, 1967 or Orthrozanclus Conway Morris and Caron, 2007. Maikhanellids are characterized by the prominent protrusions or scales on the cap-shaped shell plates arranged in a concentric pattern around the shell apex. Evolutionarily, the protrusions or scales are reduced in younger strata, whereas subsequently a typically concentric ornament developed, the cap-shaped shell plates developed higher profiles, and the apical region became increasingly bare of scales. Meanwhile, the cap-shaped shell plates gradually evolved into a helcionellid-like appearance with an anteroposteriorly inclined apex. The morphological evolution of the earliest sclerotized mollusks reflects biotic evolution and environmental adaption among the stem-group mollusks during the early Cambrian.

Background: Singapore General Hospital (SGH) is the largest acute tertiary-care hospital in Singapore. Healthcare workers (HCWs) are at risk of acquiring COVID-19 in both the community and workplaces. SGH has a robust exposure management process including prompt contact tracing, immediate ring fencing, lock down of affected cubicles or single room isolation for patient contacts, and home isolation orders for staff contacts of COVID-19 cases during the containment phase of the pandemic. Contacts were also placed on enhanced surveillance with PCR testing on days 1 and 4 as well as daily antigen rapid tests (ARTs) for 10 days after exposure. Here, we describe the characteristic of HCWs with COVID-19 during the third wave of the COVID-19 pandemic. Methods: This retrospective observational study included all SGH HCWs who acquired COVID-19 during the third wave (ie, the 18-week period from September 1 to December 31, 2021) of the COVID-19 pandemic. Univariate analysis was used to compare characteristics of work-associated infection (WAI) and community-acquired infection (CAI) among HCWs. Results: Among a workforce of >10,000 at SGH, 335 HCWs acquired COVID-19 during study period. CAI (exposure to known clusters or household contact) accounted for 111 HCW infections (33.1%). Also, 48 HCWs (14.3%) had a WAI (ie, acquired at their work places where there was no patient contact). Among WAsI, only 5 HCWs had hospital-acquired infection (confirmed by phylogenetic analysis). The sources of exposure for the remaining 176 HCWs were unknown. Weekly incidence of COVID-19 among HCWs was comparable to the epidemiology curve of all cases in Singapore (Fig. 1 and 2). The mean age of HCWs with COVID-19 was 39.6 years, and most were women. At the time of positive SARS-CoV-2 PCR test, 223 HCWs were symptomatic, and 67 (20.0%) of them had comorbidities. Only 16 HCWs (4.8%) required hospitalization, and all recovered fully with no mortality (Table 1). Being female was associated with community COVID-19 acquisition (OR, 4.6, P Conclusions: During the thrid wave of the COVID-19 pandemic, a higher percentage of HCWs at SGH acquired the infection from the community than from the workplace. Safe management measures, such as universal masking, social distancing, and robust exposure management processes including prompt contact tracing and environmental disinfection, can reduce the risk of COVID-19 in the hospital work environment.

Funding: None

Disclosures: None

Lower-crust-derived adakitic rocks in the Gangdese belt provide important constraints on the timing of Tibetan crustal thickening and on the relative contributions of magmatic and tectonic processes. Here we present geochronological and geochemical data for the Wangdui porphyritic monzogranites in the western Gangdese belt. Zircon U–Pb dating yields emplacement ages of 46–44 Ma. All samples have high Sr (321–599 ppm), low Yb (0.76–1.33 ppm) and Y (10.6–18.3 ppm) contents, with high La/Yb (51.1–72.3) and Sr/Y (21.0–51.4) ratios, indicating adakitic affinities. The low MgO (0.97–1.76 wt %), Cr (7.49–53.6 ppm) and Ni (4.75–29.1 ppm) contents, as well as high 87Sr/86Sr(i) (0.7143–0.7145), low ϵNd(t) (−10.4 to −9.8) and zircon ϵHf(t) (−17.7 to 0.4) values, suggest that the Wangdui pluton most likely originated from partial melting of the thickened ancient lower crust. In combination with previously published data, despite the east–west-trending heterogeneity of crustal composition in the Gangdese belt, the La/Yb ratios of magmatic rocks reveal that both western and eastern segments experienced remarkable crustal thickening in the Eocene. However, in contrast to the thickened juvenile lower crust in the eastern segment formed by the underplating of mantle-derived magmas, tectonic shortening plays a more crucial role in thickening of the ancient basement in western Gangdese. In fact, such Eocene-thickened ancient lower-crust-derived adakitic rocks are widely distributed in the central Himalayan–Tibetan orogen. This, together with the extensive development of fold–thrust belts, suggests that tectonic shortening might be the main mechanism accounting for the crustal thickening associated with the India–Asia collision.

The propulsion of a pitching flexible plate in a uniform flow is investigated numerically. The effects of bending stiffness ($K$), pitching amplitude ($A_L$) and frequency ($St$) on the wake patterns, thrust generations and propulsive performances of the fluid–plate system are analysed. Four typical wake patterns, i.e. von Kármán, reversed von Kármán, deflected and chaotic wakes, emerge from various kinematics, and the $St-A_L$ wake maps are given for various $K$. The drag-to-thrust transitions (DTT) and the wake transitions (WT) between the von Kármán and reversed von Kármán wakes are examined. Results indicate that the WT and DTT boundaries can be scaled by the chord-averaged distance of travel, $\mathcal {L}$, which leads to $\mathcal {L}\times St \approx 1$ and $\mathcal {L}\times St \approx 1.2$, respectively. Further, the resonance mechanism for the performance enhancement is revealed and confirmed in a wide range of parameters. The dimensionless average speed of plate, $\mathcal {U^*}\left (=\mathcal {L}\times St\right )$, is adopted merely to characterize the propulsive performances. For the first time, the $\mathcal {U^*}$-based scaling laws for the thrust and power are revealed in pitching rigid and flexible plates for various $A_L$ and $St$. This study may deepen our understanding of biological swimming and flying, and provide a guide for bionic design.

Sporadic clusters of healthcare-associated coronavirus disease 2019 (COVID-19) occurred despite intense rostered routine surveillance and a highly vaccinated healthcare worker (HCW) population, during a community surge of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) B.1.617.2 δ (delta) variant. Genomic analysis facilitated timely cluster detection and uncovered additional linkages via HCWs moving between clinical areas and among HCWs sharing a common lunch area, enabling early intervention.

The effect of hydrodynamic interactions on the collective locomotion of fish schools is still poorly understood. In this paper, the flow-mediated organization of two tandem flapping foils, which are free in both the longitudinal and lateral directions, is numerically studied. It is found that the tandem formation is unstable for two foils when they can self-propel in both the longitudinal and lateral directions. Three types of resultant regular formations are observed, i.e. semi-tandem formation, staggered formation and transitional formation. Which type of regular formation occurs depends on the flapping parameters and the initial longitudinal distance between the two foils. Moreover, there is a threshold value of the cycle-averaged longitudinal distance (which is approximately 0.55) below which both velocity enhancement and efficiency augmentation can be achieved by two foils in regular formations. The results obtained here may shed some light on understanding the emergence of regular formations of fish schools.

Embryo quality determines the success of in vitro fertilization and embryo transfer (IVF-ET) treatment. Biomarkers for the evaluation of embryo quality have some limitations. Apoptosis in cumulus cells (CCs) is important for ovarian function. PTEN (phosphatase and tensin homolog) is a well known tumour suppressor gene that functions as a mediator of apoptosis and is crucial for mammalian reproduction. In the present study, we analyzed the expression level of PTEN in human CCs and aimed to investigate its association with embryo developmental competence in IVF treatment cycles. The PTEN mRNA level in CCs was measured using real-time fluorescence quantitative PCR. The association of the differential expression of PTEN with embryo quality was analyzed. Our data showed that PTEN mRNA levels were significantly decreased in CCs surrounding mature oocytes compared with immature oocytes. Similar changes were found in the analysis of fertilization and blastocyst formation. The speculation that the measurement of PTEN mRNA levels in human CCs would provide a useful tool for selecting oocytes with greater chances to implant into the uterus needs to be further verified through single-embryo transfer in the future. The proapoptotic mechanism of PTEN in human reproduction needs to be further studied.