[Progress in the pathogenesis of post-infectious persistent cough]

Respiratory viral infection is a common cause of acute cough. After the cause has been cleared and the symptoms such as fever, nasal congestion and runny nose have been relieved, some patients still have persistent cough. These phenomena indicate that respiratory viruses may mediate cough hypersensitivity and lead to the occurrence of sub-acute or chronic cough. Cough response to viral infection is a protective strategy to prevent the spread of the viruses from the upper respiratory tract to other sites, but excessive coughing becomes a disease. In this review, we introduced the research progress in the pathophysiological mechanism of post-viral persistent cough or chronic cough.

Rotary table wobble error analysis and correction of a rotating accelerometer gravity gradiometer

In a rotating accelerometer gravity gradiometer (RAGG), rotary table wobble refers to the shift in the direction of the spin axis during operation. This motion causes errors in the output of the RAGG, but the mechanism is not clear. The purpose of this paper is to analyze the relationship between rotary table wobble and RAGG errors and to propose a method for rejecting these errors. We consider the influence of attitude changes, angular velocity, and angular acceleration caused by the wobble on the specific force, and we describe the error transmission process based on the accelerometer configuration and its measurement principle. Furthermore, we show through a simulated experiment that when the angular velocity noise caused by the wobble is 1 μrad/s, this will produce errors of tens of E. We propose a post-error correction method that is based on the higher-precision RAGG model and motion measurement. The errors in the two channels of the RAGG are reduced to 3.69 E and 1.85 E after error correction. The error analysis of the effects of wobble on a RAGG and the proposed error correction method are of great significance for the development of high-precision gradiometers.

A 2-year locomotive exploration and scientific investigation of the lunar farside by the Yutu-2 rover

The lunar nearside has been investigated by many uncrewed and crewed missions, but the farside of the Moon remains poorly known. Lunar farside exploration is challenging because maneuvering rovers with efficient locomotion in harsh extraterrestrial environment is necessary to explore geological characteristics of scientific interest. Chang'E-4 mission successfully targeted the Moon's farside and deployed a teleoperated rover (Yutu-2) to explore inside the Von Kármán crater, conveying rich information regarding regolith, craters, and rocks. Here, we report mobile exploration on the lunar farside with Yutu-2 over the initial 2 years. During its journey, Yutu-2 has experienced varying degrees of mild slip and skid, indicating that the terrain is relatively flat at large scales but scattered with local gentle slopes. Cloddy soil sticking on its wheels implies a greater cohesion of the lunar soil than encountered at other lunar landing sites. Further identification results indicate that the regolith resembles dry sand and sandy loam on Earth in bearing properties, demonstrating greater bearing strength than that identified during the Apollo missions. In sharp contrast to the sparsity of rocks along the traverse route, small fresh craters with unilateral moldable ejecta are abundant, and some of them contain high-reflectance materials at the bottom, suggestive of secondary impact events. These findings hint at notable differences in the surface geology between the lunar farside and nearside. Experience gained with Yutu-2 improves the understanding of the farside of the Moon, which, in return, may lead to locomotion with improved efficiency and larger range.

Promoting the doping efficiency and photoluminescence quantum yield of Mn-doped perovskite nanocrystals via two-step hot-injection

Manganese-doped perovskite nanocrystals (NCs) have been synthesized by a novel two-step hot-injection strategy with an unprecedented Mn doping efficiency of 48.5%, bright orange emission under ultraviolet light and X-ray excitation and a photoluminescence quantum yield of 84.4%, making them excellent luminescent materials.

[An optimized protocol of meniscus cell extraction for single-cell RNA sequencing]

OBJECTIVE

To optimize the protocol of meniscus cell extraction to enhance the efficiency of cell suspension preparation and maintain a high cell viability for single-cell RNA sequencing.

METHODS

We compared the efficiency of the routine cell extraction methods (short-time digestion and long-time digestion) and the optimized protocol for obtaining meniscus cell suspensions by evaluating the cell number obtained and the cell viability. Single-cell RNA sequencing datasets were analyzed to evaluate the stability of the cell suspension prepared using the optimized protocol. The reliability of the optimized protocol was assessed by comparing the single-cell RNA sequencing dataset obtained by the optimized protocol with published single-cell RNA sequencing datasets of the meniscus.

RESULTS

The optimized protocol harvested a greater number of cells (over 1×10⁵) than the routine protocols. The cell suspension prepared with the optimized protocol showed a cell viability higher than 80%, the highest among the 3 methods. Analysis of single-cell RNA sequencing datasets showed that the ratio of the mitochondrial genes was below 20% in over 80% of the cells. CD34⁺ cells, MCAM⁺ cells and COL1A1⁺ cells were identified in the datasets. Comparison with the publish datasets showed that the optimized protocol was capable of harvesting COL3A1⁺, COL1A1⁺, MYLK⁺, BMP2⁺, CD93⁺ and CDK1⁺ cells.

CONCLUSION

Single-cell suspension prepared from the meniscus can be stably obtained using the optimized protocol for single-cell RNA sequencing using the 10× Genomics platform.

Regularly fluctuating somatic cell count pattern in dairy herds

Online somatic cell count (SCC) measurement is widely used in dairy herds milked with automatic milking systems (AMS) and gives the opportunity to closely monitor individual cow udder health. Using automated SCC data, we observed cows displaying a remarkably regularly fluctuating SCC (rfSCC) pattern, which is described in this study. We aimed to (1) estimate the prevalence of rfSCC in cows milked by AMS, (2) characterize the rfSCC pattern, and (3) identify factors potentially associated with the rfSCC pattern. We analyzed 30-d episodes of composite SCC recordings of 1,000 cows from 55 dairy herds from 6 countries using an AMS with automated SCC measurement, and we identified the rfSCC pattern in 4.7% (95% CI: 3.5-6.2%) of these episodes. The rfSCC episodes had a median SCC of 701 × 1,000 cells/mL (2.5-97.5% quantile: 539-1,162), a median amplitude of 552 × 1,000 cells/mL (2.5-97.5% quantile: 409-886), and a median cycle length of 4.1 d (2.5-97.5% quantile: 3.7-4.9). Bacteriological culture data from quarter-milk samples collected every 2 wk in 1 Dutch AMS herd were analyzed, yielding no clear association between pathogen species and the rfSCC pattern found in that herd. Altogether, we described an intriguing phenomenon, present in almost 5% of the cows during a 1-mo study period. Further work is needed to quantify its importance in terms of udder health, but also to elucidate the mechanism behind this remarkable SCC pattern.

Synthesis of two-dimensional phenylethylamine tin-lead halide perovskites with bandgap bending behavior

Recently, two-dimensional (2D) metal halide perovskite materials with wide application in perovskite-based solar cells have attracted significant attention. Among them, 2D mixed lead-tin perovskites have not been systematically explored. Herein, we synthesize a 2D phenethylammonium (PEA) tin-lead bromide perovskite, PEA₂Sn _x Pb_1-x Br₄, via a simple solution-phase approach without toxic reagents and high temperatures. By tuning the ratio of Sn and Pb, the UV-vis absorption spectra showed unique bandgap bending behaviors. DFT calculations indicate the key effects of spin-orbital coupling (SOC) without the interference of lattice distortion. Moreover, we provided the standard equation with a correction term to introduce the influence of SOC. These results not only provide a step forward towards the bandgap engineering of perovskites, but also help to expand the application of 2D perovskite materials.

A general approach to realizing perovskite nanocrystals with insulating metal sulfate shells

The strategy of constructing the core/shell structure is of great importance in emitting semiconductor nanocrystals. However, the coating on soft metal halide perovskite nanocrystals at the single particle level remains a challenge because of the low compatibility between perovskites and common wide-band-gap semiconductors, such as ZnS and CdS. In addition, using these semiconductors as the shell layer requires high reaction temperatures, which often lead to undesirable chemical transformation. Herein we report a general route to passivate the perovskite nanocrystals by insulating metal sulfate shells. The passivating shell is created around the as-synthesized CsPbBr3 perovskite nanocrystals by initiating the reaction between an organic ammonium sulfate and a variety of metal ions in the presence of ligands. This new method allowed for creating insulating metal sulfate shells with controllable thicknesses and without unwanted chemical transformation. Importantly, these novel core/shell-structured nanocrystals show photoluminescence quantum yields near unity, highly suppressed energy transfer in film and suppressed halide exchange in solution.

All-Inorganic Quantum-Dot LEDs Based on a Phase-Stabilized α-CsPbI3 Perovskite

The all-inorganic nature of CsPbI₃ perovskites allows to enhance stability in perovskite devices. Research efforts have led to improved stability of the black phase in CsPbI₃ films; however, these strategies-including strain and doping-are based on organic-ligand-capped perovskites, which prevent perovskites from forming the close-packed quantum dot (QD) solids necessary to achieve high charge and thermal transport. We developed an inorganic ligand exchange that leads to CsPbI₃ QD films with superior phase stability and increased thermal transport. The atomic-ligand-exchanged QD films, once mechanically coupled, exhibit improved phase stability, and we link this to distributing strain across the film. Operando measurements of the temperature of the LEDs indicate that KI-exchanged QD films exhibit increased thermal transport compared to controls that rely on organic ligands. The LEDs exhibit a maximum EQE of 23 % with an electroluminescence emission centered at 640 nm (FWHM: ≈31 nm). These red LEDs provide an operating half-lifetime of 10 h (luminance of 200 cd m^-2 ) and an operating stability that is 6× higher than that of control devices.

TGIF2 promotes cervical cancer metastasis by negatively regulating FCMR

OBJECTIVE

We aimed at studying the correlation between TGIF2 expression and clinicopathological features of cervical cancer (CCa). The relationship between TGIF2 and FCMR and its influence on the proliferation and metastasis of tumor cells were investigated using molecular biology techniques, so as to reveal the pathogenesis of CCa and provide a new target for clinical treatment.

PATIENTS AND METHODS

TGIF2 expression in 60 pairs of cervical tumors and paracancerous tissues samples collected from CCa patients of our hospital was studied by quantitative real-time polymerase chain reaction (qPCR) analysis, and the association between TGIF2 expression and the clinical indicators or prognosis of CCa patients were analyzed. CCa cells with TGIF2 knockdown were constructed using transfection technology. Changes in the biological phenotypes (proliferation, migration, invasion) of CCa cells C33-A and HeLa after TGIF2 knockdown were determined by Cell Counting Kit-8 (CCK-8) and transwell assays. In addition, the effects of TGIF2/FCMR axis on CCa metastasis were further explored in nude mice in vivo.

RESULTS

Our data revealed a significant increase in TGIF2 mRNA expression in CCa tissue specimens compared to adjacent ones, and the increasing degree was positively correlated with the incidence of lymph node or distant metastasis of CCa patients. The results of CCK-8 and transwell suggested that knocking down TGIF2 effectively attenuated the proliferative ability and invasiveness of CCa cells. Luciferase assay confirmed that TGIF2 can directly bind to the DNA promoter of its target gene FCMR. Simultaneous transfection of sh-TGIF2 and sh-FCMR partially reversed the inhibitory effect of single transfection of TGIF2 knockdown on the malignant progression of CCa. Experiments in nude mice also suggested that TGIF2 could promote CCa tumorigenesis through the modulation of FCMR expression.

CONCLUSIONS

In summary, TGIF2 can promote the migration and proliferation ability of cervical cancer cells via down-regulating FCMR. Our study provides a new therapeutic target for the clinical treatment of cervical cancer.

Accurate diagnosis of colorectal cancer based on histopathology images using artificial intelligence

BACKGROUND

Accurate and robust pathological image analysis for colorectal cancer (CRC) diagnosis is time-consuming and knowledge-intensive, but is essential for CRC patients' treatment. The current heavy workload of pathologists in clinics/hospitals may easily lead to unconscious misdiagnosis of CRC based on daily image analyses.

METHODS

Based on a state-of-the-art transfer-learned deep convolutional neural network in artificial intelligence (AI), we proposed a novel patch aggregation strategy for clinic CRC diagnosis using weakly labeled pathological whole-slide image (WSI) patches. This approach was trained and validated using an unprecedented and enormously large number of 170,099 patches, > 14,680 WSIs, from > 9631 subjects that covered diverse and representative clinical cases from multi-independent-sources across China, the USA, and Germany.

RESULTS

Our innovative AI tool consistently and nearly perfectly agreed with (average Kappa statistic 0.896) and even often better than most of the experienced expert pathologists when tested in diagnosing CRC WSIs from multicenters. The average area under the receiver operating characteristics curve (AUC) of AI was greater than that of the pathologists (0.988 vs 0.970) and achieved the best performance among the application of other AI methods to CRC diagnosis. Our AI-generated heatmap highlights the image regions of cancer tissue/cells.

CONCLUSIONS

This first-ever generalizable AI system can handle large amounts of WSIs consistently and robustly without potential bias due to fatigue commonly experienced by clinical pathologists. It will drastically alleviate the heavy clinical burden of daily pathology diagnosis and improve the treatment for CRC patients. This tool is generalizable to other cancer diagnosis based on image recognition.

Lead-free Mn-doped antimony halide perovskite quantum dots with bright deep-red emission

We reported the first synthesis of Mn2+ doped Cs3Sb2Clx/Br9-x (0 ≤ x ≤ 9) perovskite quantum dots (PQDs) by regulating the coprecipitation of Mn2+ and Sb3+ with thiol ligands. These lead-free PQDs demonstrated bright photoluminescence emission centered at 660 nm and a high quantum yield of ∼49%, making them suitable for optical applications.

Community diversity and abundance of ammonia-oxidizing archaea and bacteria in shrimp pond sediment at different culture stages

AIMS

Ammonia oxidation is a significant process of nitrogen cycles in a lot of ecosystems sediments while there are few studies in shrimp culture pond (SCP) sediments. This paper attempted to explore the community diversity and abundance of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in SCP sediments at different culture stages.

METHODS AND RESULTS

We collected SCP sediments and analysed the community diversity and abundance of AOA and bacteria in shrimp pond sediment at different culture stages using the ammonia monooxygenase (amoA) gene with quantitative PCR (qPCR) and 16S rRNA gene sequencing. The AOB-amoA gene abundance was showed higher than AOA-amoA gene abundance in SCP sediments on Day 50 and Day 60 after shrimp larvae introducing into the pond, and the diversity of AOA in SCP sediments was higher than that of AOB. The phylogenetic tree revealed that the most of AOA were the member of Nitrosopumilus and Nitrososphaera, and the majority of AOB sequences were clustered into Nitrosospira, Nitrosomonas clusters 6a and 7. The AOA community has close relationship with total organic carbon (TOC), pH, total phosphorus (TP), nitrate reductase, urease, acid phosphatase and β-glucosidase. The AOB community was related to TOC, C/N and nitrate reductase.

CONCLUSIONS

AOA and AOB play the different ecological roles in SCP sediments at different culture stages.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results suggested that the different community diversity and abundance of AOA and AOB in SCP sediments, which may improve our ecological cognition of shrimp culture stages in SCP ecosystems.

TRAF5 promotes the occurrence and development of colon cancer via the activation of PI3K/AKT/NF-κB signaling pathways

This study aimed to investigate the expression and biological functions of TRAF5 in colon cancer at tissue and cellular levels. Forty-two patients with colon cancer were included in the present study. Tumor tissues and tumor-adjacent tissues were collected from all patients. Bioinformatics was used to analyze how TRAF5 was related to metastasis and prognosis of colon cancer. Quantitative real-time polymerase chain reaction was carried out to determine the expression of mRNA. SW620 and SW480 cells were used to study the inhibition and overexpression of TRAF5, respectively. CCK-8 assay was used to examine cell proliferation. Flow cytometry was employed to investigate cell phase and apoptosis. Transwell assay was used to study migration and invasion of cells. Western blotting was utilized to test how TRAF5 expression affected the activities of PI3K/AKT/NF-κB signaling pathways. Bioinformatics showed that the expression of TRAF5 in colon cancer tissues was correlated with metastasis and prognosis of the tumor. TRAF5 mRNA expression was up-regulated in colon cancer tissues, and related to recurrence and metastasis of the cancer. In vitro experiments showed that TRAF5 expression promoted proliferation, migration, and invasion of colon cancer cells, but reduced apoptosis of the cells. Moreover, TRAF5 might exert its biological functions by activating PI3K/AKT/NF-κB signaling pathways in colon cancer cells. In conclusion, TRAF5 expression in colon cancer tissues is up-regulated and correlated with prognosis, lymphatic metastasis and clinical staging. TRAF5 promotes the occurrence and development of colon cancer by activating PI3K/ AKT/NF-κB signaling pathways, and acts as an oncogene.

Plasma exosomal miR-125a-5p and miR-141-5p as non-invasive biomarkers for prostate cancer

Predictive biomarkers for early diagnosis of prostate cancer are important for its treatment. The functional microRNAs in the exosomes of plasma and serum samples are of interest as stable and non-invasive biomarkers for recurrence in cancer patients. The present study aimed to clarify the value of plasma exosomal miRNA-125a-5p and miR-141-5p as biomarkers for the diagnosis of prostate cancer. The study included 19 healthy individuals and 31 prostate cancer patients. In comparison to the levels in healthy controls, exosomal miR-141-5p levels showed a slight increase in prostate cancer patients (p=0.085), and miR-125a-5p levels that showed a significant decrease in patients with prostate cancer than in healthy controls (p=0.032). As a derived parameter, the miR-125a-5p/miR-141-5p ratio was significantly higher in patients with prostate cancer than in healthy controls (p<0.001). We found that exosomal miR-141-5p in plasma showed a promise in distinguishing prostate cancer patients with the AUC of 0.652, and for miR-125a-5p, the AUC was 0.691. For the miR-125a-5p/miR-141-5p ratio, the AUC value was 0.793. We found that miR-125a-5p has a weak positive correlation with PSA (correlation coefficient = 0.3413). Moreover, miR-141-5p has been found to hold a negatively no-significant correlation with PSA, with the correlation coefficient is -0.1102. We speculate that, as diagnostic markers for prostate cancer, miR-125-5p and miR-141-5p might be independent of the PSA. In summary, the results of this study suggest that high plasma exosomal expression of miR-141-3p and low expression of miR-125a-5p in plasma exosomes from prostate cancer patients might be useful markers of specific tumor traits associated with prostate cancer. Moreover, the miR-125a-5p/miR-141-5p ratio seems to perform better than either of the single values alone.

In Situ Measurement of Vacuum Window Birefringence using 25Mg+ Fluorescence

Accurate control of the polarization states of laser light is important in precision measurement experiments. In experiments involving the use of a vacuum environment, the stress-induced birefringence effect of the vacuum windows will affect the polarization states of laser light inside the vacuum system, and it is very difficult to measure and optimize the polarization states of the laser light in situ. The purpose of this protocol is to demonstrate how to optimize the polarization states of the laser light based on the fluorescence of ions in the vacuum system, and how to calculate the birefringence of vacuum windows based on azimuthal angles of external wave plates with Mueller matrix. The fluorescence of ²⁵Mg⁺ ions induced by laser light that is resonant with the transition of |3²P3/2,F = 4, mF = 4 → |3²S1/2,F = 3, mF = 3 is sensitive to the polarization state of the laser light, and maximum fluorescence will be observed with pure circularly polarized light. A combination of half-wave plate (HWP) and quarter-wave plate (QWP) can achieve arbitrary phase retardation and is used for compensating the birefringence of the vacuum window. In this experiment, the polarization state of the laser light is optimized based on the fluorescence of ²⁵Mg⁺ ion with a pair of HWP and QWP outside the vacuum chamber. By adjusting the azimuthal angles of the HWP and QWP to obtain maximum ion fluorescence, one can obtain a pure circularly polarized light inside the vacuum chamber. With the information on the azimuthal angles of the external HWP and QWP, the birefringence of the vacuum window can be determined.