The selection of high-quality sperms is critical to intracytoplasmic sperm injection, which accounts for 70–80% of in vitro fertilization (IVF) treatments. So far, sperm screening is usually performed manually by clinicians. However, the performance of manual screening is limited in its objectivity, consistency, and efficiency. To overcome these limitations, we have developed a fast and noninvasive three-stage method to characterize morphology of freely swimming human sperms in bright-field microscopy images using deep learning models. Specifically, we use an object detection model to identify sperm heads, a classification model to select in-focus images, and a segmentation model to extract geometry of sperm heads and vacuoles. The models achieve an F1-score of 0.951 in sperm head detection, a z-position estimation error within ±1.5 μm in in-focus image selection, and a Dice score of 0.948 in sperm head segmentation, respectively. Customized lightweight architectures are used for the models to achieve real-time analysis of 200 frames per second. Comprehensive morphological parameters are calculated from sperm head geometry extracted by image segmentation. Overall, our method provides a reliable and efficient tool to assist clinicians in selecting high-quality sperms for successful IVF. It also demonstrates the effectiveness of deep learning in real-time analysis of live bright-field microscopy images.

The horse played a crucial role in China through the first millennium BC, used both for military advantage and, through incorporation into elite burials, to express social status. Details of how horses were integrated into mortuary contexts during the Qin Empire, however, are poorly understood. Here, the authors present new zooarchaeological data for 24 horses from an accessory pit in Qin Shihuang's mausoleum, indicating that the horses chosen were tall, adult males. These findings provide insights into the selection criteria for animals to be included in the emperor's tomb and invite consideration of questions concerning horse breeds, husbandry practices, and the military and symbolic importance of horses in early imperial China.

Let n and k be positive integers with $n\ge k+1$ and let $\{a_i\}_{i=1}^n$ be a strictly increasing sequence of positive integers. Let $S_{n, k}:=\sum _{i=1}^{n-k} {1}/{\mathrm {lcm}(a_{i},a_{i+k})}$ . In 1978, Borwein [‘A sum of reciprocals of least common multiples’, Canad. Math. Bull.20 (1978), 117–118] confirmed a conjecture of Erdős by showing that $S_{n,1}\le 1-{1}/{2^{n-1}}$ . Hong [‘A sharp upper bound for the sum of reciprocals of least common multiples’, Acta Math. Hungar.160 (2020), 360–375] improved Borwein’s upper bound to $S_{n,1}\le {a_{1}}^{-1}(1-{1}/{2^{n-1}})$ and derived optimal upper bounds for $S_{n,2}$ and $S_{n,3}$ . In this paper, we present a sharp upper bound for $S_{n,4}$ and characterise the sequences $\{a_i\}_{i=1}^n$ for which the upper bound is attained.

The surface thermodynamics and wetting condition are investigated for the recent multiphase lattice Boltzmann model with a self-tuning equation of state (EOS), where the multiphase EOS is specified in advance and the reduced temperature is set to a relatively low value. The surface thermodynamics is first explored starting from the free-energy functional of a multiphase system and a theoretical expression for the contact angle is derived for the general multiphase EOS. The conventional free-energy density for the solid surface, which is in linear form, is analysed, and it is found that the fluid density on the solid surface significantly deviates from that in the bulk phase when the reduced temperature is relatively low. A new free-energy density for the solid surface, which is in hyperbolic tangent form, is then proposed. Two independent parameters are introduced, which can dramatically reduce the density deviation and effectively adjust the contact angle, respectively. Meanwhile, the contact angle, surface tension and interface thickness can be independently adjusted in the present theoretical framework. Based on the analysed surface thermodynamics, a thermodynamically consistent treatment for the wetting condition is proposed for both straight and curved walls. Numerical tests of droplets on straight and curved walls validate the theoretical analysis of the surface thermodynamics and the present wetting condition treatment. As further applications, a moving droplet on an inclined wall, which is vertically and sinusoidally oscillated, and the evaporation of a droplet on an adiabatic substrate are simulated, and satisfying results consistent with previous studies are obtained.

Nosema bombycis is a destructive and specific intracellular parasite of silkworm, which is extremely harmful to the silkworm industry. N. bombycis is considered as a quarantine pathogen of sericulture because of its long incubation period and horizontal and vertical transmission. Herein, two single-chain antibodies targeting N. bombycis hexokinase (NbHK) were cloned and expressed in fusion with the N-terminal of Slmb (a Drosophila melanogaster FBP), which contains the F-box domain. Western blotting demonstrated that Sf9-III cells expressed NSlmb–scFv-7A and NSlmb–scFv-6H, which recognized native NbHK. Subsequently, the NbHK was degraded by host ubiquitination system. When challenged with N. bombycis, the transfected Sf9-III cells exhibited better resistance relative to the controls, demonstrating that NbHK is a prospective target for parasite controls and this approach represents a potential solution for constructing N. bombycis-resistant Bombyx mori.

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.

Athetis lepigone Möschler (Lepidoptera, Noctuidae) is a common maize pest in Europe and Asia. However, there is no long-term effective management strategy is available yet to suppress its population. Adults rely heavily on olfactory cues to locate their optimal host plants and oviposition sites. Pheromone-binding proteins (PBPs) are believed to be responsible for recognizing and transporting different odorant molecules to interact with receptor membrane proteins. In this study, the ligand-binding specificities of two AlepPBPs (AlepPBP2 and AlepPBP3) for sex pheromone components and host plant (maize) volatiles were measured by fluorescence ligand-binding assay. The results demonstrated that AlepPBP2 had a high affinity with two pheromones [(Z)-7-dodecenyl acetate, Ki = 1.11 ± 0.1 μM, (Z)-9-tetradecenyl acetate, Ki = 1.32 ± 0.15 μM] and ten plant volatiles, including (-)-limonene, α-pinene, myrcene, linalool, benzaldehyde, nonanal, 2-hexanone, 3-hexanone, 2-heptanone and 6-methyl-5-hepten-2-one. In contrast, we found that none of these chemicals could bind to AlepPBP3. Our results clearly show no significant differences in the functional characterization of the binding properties between AlepPBP2 and AlepPBP3 to sex pheromones and host plant volatiles. Furthermore, molecular docking was employed for further detail on some crucial amino acid residues involved in the ligand-binding of AlepPBP2. These findings will provide valuable information about the potential protein binding sites necessary for protein-ligand interactions which appear as attractive targets for the development of novel technologies and management strategies for insect pests.

The transition from puddled-transplanted rice (Oryza sativa L.) (PTR) to direct-seeded rice (DSR) is gaining popularity in central China. In contrast, the PTR system is the most common practice in southwest China. Weeds are a major problem in the paddy fields of the DSR systems, and herbicides are widely used for weed control. However, the increased frequency and rate of herbicide use leads to the rapid evolution of resistance. Smallflower umbrella sedge (Cyperus difformis L.) is a troublesome weed species in rice fields of China and is usually controlled by the acetolactate synthase (ALS)-inhibiting herbicide bensulfuron-methyl. Here, we collected 32 C. difformis populations from DSR systems (Hunan Province) and PTR systems (Guangxi Province) and investigated their resistance to bensulfuron-methyl. Results revealed 80% (8 out of 10) populations from Hunan Province and 14% (3 out of 22) populations from Guangxi Province had evolved resistance to bensulfuron-methyl. Five populations from Hunan Province (HN-2, HN-3, HN-5, HN-9, HN-10) possessing the Trp-574-Leu mutation had high-level resistance (ranging from 169- to >1,309-fold) based on GR50 ratios. The resistant populations from Guangxi Province had a lower level of resistance to bensulfuron-methyl due to a Pro-197-Ser mutation. The Asp-376-Glu mutation was only identified in the HN-4 population. In addition, the GX-3 population from the PTR systems was resistant to bensulfuron-methyl without ALS gene mutations, indicating non–target site resistance (NTSR). Although some resistant populations of both regions exhibited cross-resistance to multiple ALS-inhibiting herbicides, including pyrazosulfuron-ethyl, bispyribac-sodium, penoxsulam, and imazapic, sensitivity was also detected to the auxin herbicide MCPA and the photosystem II–inhibiting herbicides bentazone and propanil. These results indicate that cultivation practices affect resistance evolution in C. difformis. DSR systems exert high selection pressure by selecting the Trp-574-Leu mutation, resulting in high-level resistance. In contrast, a mutation at Pro-197 plus NTSR likely plays a significant role in ALS resistance in the PTR systems.

Due to less light scattering and a better signal-to-noise ratio in deep imaging, two-photon fluorescence microscopy (TPFM) has been widely used in biomedical photonics since its advent. However, optical aberrations degrade the performance of TPFM in terms of the signal intensity and the imaging depth and therefore restrict its application. Here, we introduce adaptive optics based on the genetic algorithm to detect the distorted wavefront of the excitation laser beam and then perform aberration correction to optimize the performance of TPFM. By using a spatial light modulator as the wavefront controller, the correction phase is obtained through a signal feedback loop and a process of natural selection. The experimental results show that the signal intensity and imaging depth of TPFM are improved after aberration correction. Finally, the method was applied to two-photon fluorescence lifetime imaging, which helps to improve the signal-to-noise ratio and the accuracy of lifetime analysis. Furthermore, the method can also be implemented in other experiments, such as three-photon microscopy, light-sheet microscopy, and super-resolution microscopy.

The epidemic of tuberculosis has posed a serious burden in Qinghai province, it is necessary to clarify the epidemiological characteristics and spatial-temporal distribution of TB for future prevention and control measures. We used descriptive epidemiological methods and spatial statistical analysis including spatial correlation and spatial-temporal analysis in this study. Furthermore, we applied an exponential smoothing model for TB epidemiological trend forecasting. Of 43 859 TB cases, the sex ratio was 1.27:1 (M:F), and the average annual TB registered incidence was 70.00/100 000 of 2009–2019. More cases were reported in March and April, and the worst TB stricken regions were the prefectures of Golog and Yushu. High TB registered incidences were seen in males, farmers and herdsmen, Tibetans, or elderly people. 7132 cases were intractable, which were recurrent, drug resistant, or co-infected with other infections. Three likely cases clusters with significant high risk were found by spatial-temporal scan on data of 2009–2019. The exponential smoothing winters' additive model was selected as the best-fitting model to forecast monthly TB cases in the future. This research indicated that TB in Qinghai is still a serious threaten to the local residents' health. Multi-departmental collaboration and funds special for TB treatments and control are still needed, and the exponential smoothing model is promising which could be applied for forecasting of TB epidemic trend in this high-altitude province.