MOFDiff: Coarse-grained Diffusion for Metal-Organic Framework Design

Metal-organic frameworks (MOFs) are of immense interest in applications such as gas storage and carbon capture due to their exceptional porosity and tunable chemistry. Their modular nature has enabled the use of template-based methods to generate hypothetical MOFs by combining molecular building blocks in accordance with known network topologies. However, the ability of these methods to identify top-performing MOFs is often hindered by the limited diversity of the resulting chemical space. In this work, we propose MOFDiff: a coarse-grained (CG) diffusion model that generates CG MOF structures through a denoising diffusion process over the coordinates and identities of the building blocks. The all-atom MOF structure is then determined through a novel assembly algorithm. Equivariant graph neural networks are used for the diffusion model to respect the permutational and roto-translational symmetries. We comprehensively evaluate our model's capability to generate valid and novel MOF structures and its effectiveness in designing outstanding MOF materials for carbon capture applications with molecular simulations.Comment: 19 pages, 12 figure

Dynamics and optimal control of a Zika model with sexual and vertical transmissions

A new transmission model of Zika virus with three transmission routes including human transmission by mosquito bites, sexual transmission between males and females and vertical transmission is established. The basic reproduction number $R_{0}$ is derived. When R_{0} < 1 , it is proved that the disease-free equilibrium is globally stable. Furthermore, the optimal control and mitigation methods for transmission of Zika virus are deduced and explored. The MCMC method is used to estimate the parameters and the reasons for the deviation between the actual infection cases and the simulated data are discussed. In addition, different strategies for controlling the spread of Zika virus are simulated and studied. The combination of mosquito control strategies and internal human control strategies is the most effective way in reducing the risk of Zika virus infection

Stellar Parameters of Main Sequence Turn-off Star Candidates Observed with the LAMOST and Kepler

Main sequence turn-off (MSTO) stars have advantages as indicators of Galactic evolution since their ages could be robustly estimated from atmospheric parameters. Hundreds of thousands of MSTO stars have been selected from the LAMOST Galactic sur- vey to study the evolution of the Galaxy, and it is vital to derive accurate stellar parameters. In this work, we select 150 MSTO star candidates from the MSTO stars sample of Xiang that have asteroseismic parameters and determine accurate stellar parameters for these stars combing the asteroseismic parameters deduced from the Kepler photometry and atmospheric parameters deduced from the LAMOST spectra.With this sample, we examine the age deter- mination as well as the contamination rate of the MSTO stars sample. A comparison of age between this work and Xiang shows a mean difference of 0.53 Gyr (7%) and a dispersion of 2.71 Gyr (28%). The results show that 79 of the candidates are MSTO stars, while the others are contaminations from either main sequence or sub-giant stars. The contamination rate for the oldest stars is much higher than that for the younger stars. The main cause for the high contamination rate is found to be the relatively large systematic bias in the LAMOST surface gravity estimates.Comment: accepted by RA

Primary intramedullary melanocytoma presenting with lower limbs, defecation, and erectile dysfunction:A case report and review of the literature

BACKGROUND: Primary intramedullary melanocytoma is an exceedingly rare type of primary melanocytic tumor in the central nervous system. Unfortunately, primary intramedullary melanocytoma lacks specificity in clinical symptoms and imaging features and there is currently no standard strategy for diagnosis or treatment. CASE SUMMARY: A 52-year-old male patient suffered from weakness and numbness involving the bilateral lower limbs for 18 mo, and defecation and erectile dysfunction for 6 mo. Furthermore, these symptoms started to worsen for the last 3 mo. Preoperative magnetic resonance imaging (MRI) revealed an intramedullary tumor located at the T9-T10 level. In subsequently surgery, the maximal safe resection extent approached to 98%. The lesion was confirmed to be melanocytoma by pathological examination. In addition, the possibility of original melanocytoma outside the spinal cord was excluded after the examination of the whole body. Therefore, a diagnosis of primary intramedullary melanocytoma was established. The patient refused to accept radiotherapy or Gamma Knife, but MRI examination on July 28, 2020 showed no sign of development. In addition, on April 10, 2021, the recent review showed that the disorder of defecation and lower limbs improved further but erectile dysfunction benefited a little from the surgery. CONCLUSION: After diagnosing intramedullary melanocytoma by postoperative pathology, the inspection of the whole body contributed to excluding the possibility of metastasis from other regions and further suggested a diagnosis of primary intramedullary melanocytoma. Complete resection, adjuvant radiation, and regular review are critical. In addition, maximal safe resection also benefits prognosis while the tumor is difficult to be resected totally

Complex sliding characteristics of landslides and evaluation of the reinforcement with arched anti-slide piles based on 3D discrete element method: a case study

Landslide movement processes often exhibit complex paths, introducing the uncertainty of landslide movement paths, and challenging landslide hazard prediction and pre-disaster prevention and control. In this study, we employed numerical simulations to investigate the dynamic processes with complex paths of the Pangjiawan landslide using the 3D discrete element method. A scenario simulation was conducted to evaluate the stability of the landslide, incorporating arched anti-slide piles, and the reinforcing effect of arch anti-slide piles on the Pangjiayan landslide under different rise-span ratios and pile spacing was analyzed in depth. The results indicate that the Pangjiawan landslide in mountainous notch topography exhibits a complex movement path with turning and convergence behaviors, and arched anti-slide piles are more effective in stabilizing the landslide than traditional linear anti-slide piles. When the embedded depth of the arched anti-slide piles remains consistent, higher rise-span ratios result in more significant synergistic effects between the piles and the surrounding soil. Moreover, even with increased pile spacing and a reduction in the number of anti-slide piles, the landslide displacement after reinforcement with arched anti-slide piles is lower than traditional linear anti-slide piles. The research provides valuable insights into the dynamics of landslide movements, emphasizing the superior reinforcement capabilities of arched anti-slide piles. This contributes to our understanding of landslide mitigation strategies in challenging topography

Cytokine-Based Generation of CD49a+Eomes−/+ Natural Killer Cell Subsets

Recent studies have identified CD49a+Eomes− and CD49a+Eomes+ subsets of tissue-resident NK (trNK) cells in different organs of the mouse. However, the characteristics of CD49a+Eomes−/+ NK cell development and the regulation of Eomes expression in NK cells remain unclear. Here, we established an in vitro cytokine-based feeder-free system in which bone marrow progenitor cells differentiate into CD49a+ NK cells. IL-15 was identified as being the key cytokine in this system that supported the development and maintenance of CD49a+ NK cells. The CD49a+ NK cells generated were Eomes−CD49b− and shared the same phenotype as hepatic trNK cells. IL-4 induced the expression of Eomes in generated NK cells and converted them into CD49a+Eomes+ cells, which were phenotypically and functionally similar to uterine trNK cells. Moreover, the IL-4/STAT6 axis was identified as being important in the generation of CD49a+Eomes+ induced NK cells. Collectively, these studies describe an approach to generate CD49a+Eomes−/+ subsets of NK cells and demonstrate important roles for IL-15 and IL-4 in the differentiation of these cells. These findings have potential for developmental research underlying the generation of different subsets of NK cells and the application of adoptive NK cell transfer therapies

Resection of unresectable hepatocellular carcinoma after conversion therapy with apatinib and camrelizumab: a case report and literature review

Hepatocellular carcinoma is a rather common malignant tumor. Most patients with hepatocellular carcinoma receive their diagnosis at an advanced stage, at which surgical resection is no longer appropriate. A growing body of research has demonstrated the value of convention therapy for patients with intermediate-stage hepatocellular carcinoma, while specific application protocols and treatment guidelines are not well developed. Emerging clinical researches suggest that a tyrosine kinase inhibitor in combination with an immune checkpoint inhibitor is a reasonable strategy for unresectable hepatocellular carcinoma. However, there are relatively few reports on the efficacy of apatinib and camrelizumab in the treatment of hepatocellular carcinoma. We were able to successfully remove one patient’s hepatocellular carcinoma after 8 cycles of conversion therapy with apatinib (250 mg orally every day) and camrelizumab (200 mg intravenously every 2 weeks). The patient continued to receive the same dose of 16 cycles of apatinib and camrelizumab after hepatectomy. By the time of this study, the patient has completed 18 months of follow-up, and no tumor recurrence or metastasis was found in tumor markers and imaging examinations. Apatinib in combination with camrelizumab is an effective therapy for the treatment of advanced hepatocellular carcinoma, and surgical resection after this conversion therapy may provide patients with long-term oncological benefits. However, this requires more samples to validate the conclusion