Global viscosity solutions to Lorentzian eikonal equation on globally hyperbolic space-times

In this paper, we show that any globally hyperbolic space-time admits at least one globally defined distance-like function, which is a viscosity solution to the Lorentzian eikonal equation. According to whether the time orientation is changed, we divide the set of viscosity solutions into some subclasses. We show if the time orientation is consistent, then a viscosity solution has a variational representation locally. As a result, such a viscosity solution is locally semiconcave, as the one in the Riemannian case. Also, if the time orientation of a viscosity solution is non-consistent, we analyse its peculiar properties which make this kind of viscosity solutions are totally different from the ones where the Hamiltonians are convex

4-(4-Chloro­phen­yl)-5-(4-nitro­phen­yl)-3-phenyl-4H-1,2,4-triazole

The title compound, C20H13ClN4O2, was synthesized by the condensation of 4-nitro­benzohydrazide and N-(4-chlorophen­yl)­benzimidoyl chloride in N,N-dimethyl­acetamide. The asymmetric unit contains two independent mol­ecules. In one molecule, the triazole ring is oriented at dihedral angles of 23.1 (5), 85.4 (1) and 10.5 (1)° with respect to the phenyl, chlorophenyl and nitrophenyl rings, respectively. In the other molecule, the corresponding dihedral angles are 29.8 (9), 73.4 (7) and 16.4 (3)°

CTP: Towards Vision-Language Continual Pretraining via Compatible Momentum Contrast and Topology Preservation

Vision-Language Pretraining (VLP) has shown impressive results on diverse downstream tasks by offline training on large-scale datasets. Regarding the growing nature of real-world data, such an offline training paradigm on ever-expanding data is unsustainable, because models lack the continual learning ability to accumulate knowledge constantly. However, most continual learning studies are limited to uni-modal classification and existing multi-modal datasets cannot simulate continual non-stationary data stream scenarios. To support the study of Vision-Language Continual Pretraining (VLCP), we first contribute a comprehensive and unified benchmark dataset P9D which contains over one million product image-text pairs from 9 industries. The data from each industry as an independent task supports continual learning and conforms to the real-world long-tail nature to simulate pretraining on web data. We comprehensively study the characteristics and challenges of VLCP, and propose a new algorithm: Compatible momentum contrast with Topology Preservation, dubbed CTP. The compatible momentum model absorbs the knowledge of the current and previous-task models to flexibly update the modal feature. Moreover, Topology Preservation transfers the knowledge of embedding across tasks while preserving the flexibility of feature adjustment. The experimental results demonstrate our method not only achieves superior performance compared with other baselines but also does not bring an expensive training burden. Dataset and codes are available at https://github.com/KevinLight831/CTP.Comment: Accepted by ICCV 2023. Code: https://github.com/KevinLight831/CT

Pulsar discovery prospect of FASTA

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) has discovered more than 650 new pulsars, which account for 20% of our known Galactic pulsar population. In this paper, we estimate the prospect of a pulsar survey with a radio telescope array to be planned -- the FAST Array (FASTA), consists of six "FAST-type" telescopes. Such a sensitive radio telescope array would be a powerful instrument in probing the pulsar population deep into our Galaxy as well as in nearby galaxies. We simulate the FASTA pulsar discovery prospects with different Galactic pulsar population models and instrumental parameter combinations. We find that FASTA could detect tens of thousands of canonical pulsars and well-over thousands of millisecond pulsars. We also estimate the potential yield if the FASTA is used to search for pulsars from the nearby spiral galaxy M31, and find that it would probably discover around a hundred new radio pulsars

Improvement of tissue preparation for laser capture microdissection: application for cell type-specific miRNA expression profiling in colorectal tumors

<p>Abstract</p> <p>Background</p> <p>Laser capture microdissection (LCM) has successfully isolated pure cell populations from tissue sections and the combination of LCM with standard genomic and proteomic methods has revolutionized molecular analysis of complex tissue. However, the quantity and quality of material recovered after LCM is often still limited for analysis by using whole genomic and proteomic approaches. To procure high quality and quantity of RNA after LCM, we optimized the procedures on tissue preparations and applied the approach for cell type-specific miRNA expression profiling in colorectal tumors.</p> <p>Results</p> <p>We found that the ethanol fixation of tissue sections for 2 hours had the maximum improvement of RNA quality (1.8 fold, p = 0.0014) and quantity (1.5 fold, p = 0.066). Overall, the quality (RNA integrity number, RIN) for the microdissected colorectal tissues was 5.2 ± 1.5 (average ± SD) for normal (n = 43), 5.7 ± 1.1 for adenomas (n = 14) and 7.2 ± 1.2 for carcinomas (n = 44). We then compared miRNA expression profiles of 18 colorectal tissues (6 normal, 6 adenomas and 6 carcinomas) between LCM selected epithelial cells versus stromal cells using Agilent miRNA microarrays. We identified 51 differentially expressed miRNAs (p <= 0.001) between these two cell types. We found that the miRNAs in the epithelial cells could differentiate adenomas from normal and carcinomas. However, the miRNAs in the stromal and mixed cells could not separate adenomas from normal tissues. Finally, we applied quantitative RT-PCR to cross-verify the expression patterns of 7 different miRNAs using 8 LCM-selected epithelial cells and found the excellent correlation of the fold changes between the two platforms (R = 0.996).</p> <p>Conclusions</p> <p>Our study demonstrates the feasibility and potential power of discovering cell type-specific miRNA biomarkers in complex tissue using combination of LCM with genome-wide miRNA analysis.</p

Co-administration of a DNA vaccine encoding the prostate specific membrane antigen and CpG oligodeoxynucleotides suppresses tumor growth

BACKGROUND: Prostate-specific membrane antigen (PSMA) is a well characterized prostate-specific tumor associated antigen. Its expression is elevated in prostate carcinoma, particularly in metastatic and recurrent lesions. These observations suggest that PSMA can be used as immune target to induce tumor cell-specific recognition by the host and, consequently tumor rejection. We utilized a DNA-based vaccine to specifically enhance PSMA expression. An immune modulator, such as CpG oligodeoxynucleotides which promote Th1-type immune responses was combined to increase the efficacy of tumor recognition and elimination. METHODS: A eukaryotic expression plasmid pCDNA3.1-PSMA encoding full-length PSMA was constructed. C57BL/6 mice were immunized with endotoxin-free pCDNA3.1-PSMA alone or in combination with CpG oligodeoxynucleotides by intramuscular injection. After 4 immunizations, PSMA specific antibodies and cytotoxic T lymphocyte reactivity were measured. Immunized C57BL/6 mice were also challenged subcutaneously with B16 cells transfected with PSMA to evaluate suppression of tumor growth. RESULTS: Vaccine-specific cytotoxic T lymphocytes reactive with B16 cells expressing PSMA could be induced with this treatment schedule. Immune protection was observed in vaccinated mice as indicated by increased tumor growth in the control group (100%) compared with the groups vaccinated with DNA alone (66.7%) or DNA plus CpG oligodeoxynucleotides (50%) respectively. Average tumor volume was smaller in vaccinated groups and tumor-free survival time was prolonged by the vaccination. CONCLUSION: The current findings suggest that specific anti-tumor immune response can be induced by DNA vaccines expressing PSMA. In addition, the suppression of in vivo growth of tumor cells expressing PSMA was augmented by CpG oligodeoxynucleotides. This strategy may provide a new venue for the treatment of carcinoma of prostate after failure of standard therapy

Identification and Functional Evaluation of miR-4633-5p as a Biomarker and Tumor Suppressor in Metastatic Melanoma

Background/Aims: Sinonasal mucosal melanoma (SMM) is a rare but extremely aggressive disease. Interestingly, however, as lethal as SMM, a few patients could survive for over 5 years without metastasis. However, biomarkers for metastatic SMM are lacking. Methods: Laser-capture microdissection combined with microRNA microarray and RT-qPCR was performed in formalin-fixed paraffin-embedded tissue samples from SMM patients whose follow-up studies were carried out in parallel. In vitro cell proliferation and invasion assays, gelatin zymography, western blot analysis and RT-qPCR were performed in melanoma cell lines. Results: In the discovery stage, miR-4633-5p expressed differentially in sinonasal mucosal melanoma patients with short and long disease-specific survival. Subsequent large-sample validation revealed that expression of miR-4633-5p was lower in metastatic SMM than in non-metastatic patients (P&#x3c; 0.001). Moreover, miR-4633-5plow was able to identify metastatic SMM with specificity of 100% (5/5) and sensitivity of 87.5% (21/24). Multivariate analysis further pinpointed miR-4633-5p as an independent marker for metastasis (relative risk: 54.22, P&#x3c; 0.001). In vitro, overexpression of miR-4633-5p suppressed the growth and invasiveness of melanoma cells through inhibiting activation of Akt pathway and secretion of MMP2, while knockdown of miR-4633-5p reversed the inhibitory effects. Conclusion: Our findings underpin miR-4633-5p as a predictive biomarker in metastatic SMM and a pivotal tumor suppressor that negatively regulates the invasive growth of melanoma cells. Quantitative detection of miR-4633-5p can diagnostically predict the risk of metastasis in SMM patients, which, in turn, may lead to more personalized treatment with better prognosis

Nonlinear dynamics study of a high-temperature rotor-bearing-seal system in gas turbine

Most of the major faults in gas turbines often originate from the rotor shaft. Some of these faults could result to misalignment, imbalance, crack, rub-impact and eccentricity. This study analyzes nonlinear factors such as lube-film surge and thermal-stress. Seal and bearing quality significantly affect the performance of a rotor system. The nonlinear dynamic characteristics of a high-temperature rotor–bearing–seal coupled system are investigated. Dynamic trajectories, Poincaré maps, frequency spectra diagrams are used to analyze the features of the rotor-bearing-seal coupled system in terms of various parameters. Several nonlinear phenomena in the high-temperature rotor–bearing–seal coupled system, such as periodic, double-periodic, multi-periodic, and quasi-periodic motion are investigated. Through these curves and the program, the dynamic characteristics of gas turbine rotors could be easily and accurately calculated. To validate this method, the critical speed of a real rotor of an actual gas turbine was calculated by means of the program and curves. The results are consistent with the measured data and may contribute to further understanding the nonlinear dynamics of the high-temperature rotor-bearing-seal coupled system