Integrability analysis of a simple model for describing convection of a rotating fluid

We study the Darboux integrability of a simple system of three ordinary differential equations called the Glukhovsky-Dolzhansky system, which describes a three-mode model of rotating fluid convection inside the ellipsoid. (1) Our results show that it has no polynomial, rational, or Darboux first integrals for any value of parameters in the physical sense, that is, positive parameters. (2) We also provide some integrable cases of this model when parameters are allowed to be non-positive. (3) We finally give some links between the Glukhovsky-Dolzhansky system and other similar systems in $\mathbb{R}^3$, which admits rotational symmetry and has three nonlinear cross terms

Formal First Integrals of General Dynamical Systems

The goal of this paper is trying to make a complete study on the integrability for general analytic nonlinear systems by first integrals. We will firstly give an exhaustive discussion on analytic planar systems. Then a class of higher dimensional systems with invariant manifolds will be considered; we will develop several criteria for existence of formal integrals and give some applications to illustrate our results at last

Decision-making of portfolio investment with linear plus double exponential utility function

This paper broadens the exponential utility function commonly used by risk-averse investors to the linear plus double exponential utility function, which is applicable in most cases. Thus it is of essential and supreme significance to conduct a research on its optimal investment portfolio in securities investment. This paper, by means of the non-difference curve method, carries out a research into the optimal portfolio decision-making by investors who have this type of utility function. The optimal decision-making and the ratio of optimal portfolio investment are derived. Finally, an actual case is given to verify the relevant results

Continuation of Aspirin Therapy before Cataract Surgery with Different Incisions: Safe or Not?

Purpose. To assess whether to continue aspirin therapy while having uncomplicated phacoemulsification cataract surgery with different incisions. Methods. Consecutive patients having cataract surgery under topical anesthesia with different incisions between May 2016 and August 2017 were followed. 236 eyes of 166 patients on routine aspirin therapy were randomized into 2 groups: continuation group, 112 eyes; discontinuation group, 124 eyes. 121 eyes of 94 patients on no routine anticoagulant therapy were used as the control group. Patients were examined 1 day preoperatively and 1 day and 7 days postoperatively. Intraoperative and postoperative complications were recorded. Results. Statistically, there was no significant difference about postoperative BCVA among three groups. A higher incidence of subconjunctival hemorrhage was shown in the continuation group than in the discontinuation group and the control group (17.0% versus 8.1%, p=0.038; 17.0% versus 7.4%, p=0.025, resp.). Although corneal edema was greater in clear corneal incision cases than that of scleral tunnel incision cases (22.5% versus 12.0%, p=0.009), subconjunctival hemorrhage was greater in scleral tunnel incision cases (14.9% versus 6.6%, p=0.011). Subgroup analyses revealed that patients of scleral tunnel incision who continued taking aspirin had a higher incidence of subconjunctival hemorrhage compared with those who discontinued (25.5% versus 10.9%, p=0.038), but no same conclusion in clear corneal incision cases (8.8% versus 5.0%, p=0.483). Conclusions. The outcomes indicated that phacoemulsification cataract surgery under topical anesthesia could be safely performed without ceasing systemic aspirin therapy. Clear corneal incision could be a better choice in patients treated with aspirin

Generation of a homozygous RANGRF knockout hiPSC line by CRISPR/Cas9 system

The RAN Guanine Nucleotide Release Factor (RANGRF) gene encodes the protein MOG1, which binds to Nav1.5 and facilitates its transport to the cell membrane. Nav1.5 mutations have been linked to various cardiac arrhythmias and cardiomyopathy. To investigate the role of RANGRF in this process, we utilized the CRISPR/Cas9 gene editing system to generate a homozygous RANGRF knockout hiPSC line. The availability of the cell line will prove to be an invaluable asset in the study of disease mechanisms and the testing of gene therapies for cardiomyopathy

<i>Bcl</i>-<i>xL</i> Promotes the Survival of Motor Neurons Derived from Neural Stem Cells

Neural stem cell (NSC) transplantation creates new hope for the treatment of neurodegenerative disorders by direct differentiation into neurons. However, this technique is limited by poor survival and functional neuron deficiency. In this research study, we generated pro-survival murine NSCs (mNSCs) via the ectopic expression of Bcl-xL. A doxycycline (Dox)-inducible Ngn2-Isl1-Lhx3 system was also integrated into the mNSC genome. The four gene-modified mNSCs can rapidly and effectively differentiate into motor neurons after Dox treatments. Ectopic Bcl-xL could resist replating-induced stress, glutamate toxicity, neuronal apoptosis and remarkably promote the survival of motor neurons. Taken together, we established genetically modified mNSCs with improved survival, which may be useful for motor neuron degenerative diseases

Efficient and Safe Editing of Porcine Endogenous Retrovirus Genomes by Multiple-Site Base-Editing Editor

Gene-modified miniature pigs serve as alternative tissue and organ donors for xenotransplantation to alleviate the shortage of human allogenic organs. However, the high copy number of porcine endogenous retrovirus (PERV) genomes integrates with the porcine genome, which has a potential risk of cross-species transmission and hinders the clinical practice of xenotransplantation. Recently, CRISPR/Cas9 has been used to inactivate PERVs. However, Cas9 also triggers severe DNA damage at multiple integrated PERV sites in the porcine genome, which induces senescence and apoptosis of porcine cells. In this study, the cytosine base editor (CBE), an efficient and safe editor that does not cause DNA double strand breaks (DSBs), was used for PERV editing to reduce cytotoxic effects. Seven sgRNAs were set to target gag and pol loci of PERVs to induce premature stop codons. We found that approximately 10% of cell clones were completely inactivated for PERVs in pig ST cells, and the plasmid that was used for editing the PERVs did not integrate into host genome and influence the karyotype of the modified cells. Our studies offer a powerful and safe strategy for further generating PERV-knockout pigs using base editors