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Among the errors in precision machining, thermal error has been recognized as the most significant error. The heat of the nut in the feed drive system plays an important role in the thermal error generated by the feed drive system. To better estimate and further understand the increase in temperature and thermal deformation of the ball screw during operation, a new correlation equation for the frictional torque of the nut is proposed and determined in this study for the calculation of the frictional torque of the nut and the heat generated by the nut at different feed velocities and nut temperatures. In this study, a set of devices for measuring the frictional torque of the nut under different feed velocities and different nut temperatures is designed and established. Various experimental conditions are designed to measure the frictional torque of the nut at different feed velocities and different nut temperatures to establish a correlation equation for the frictional torque of the nut. In addition, for further confirmation, the method for measuring the frictional torque of the nut used in this study is compared with the method using a handheld digital force gauge. The correlation equation for the frictional torque of the nut established in this study is based on the LuGre model and the formula of the frictional torque due to the viscosity of the lubricant of the bearing at different temperatures. The results show that the root-mean-square error between the frictional torque of the nut calculated by the correlation equation and that measured experimentally is 0.0301 N-m, indicating that the correlation equation for the frictional torque of the nut proposed in this study is accurate and feasible.

Retinopathy is a well-known ocular complication that occurs in patients with type 2 diabetes (T2D). Recent evidence also indicates that diabetic patients have an increased prevalence of dry eye syndrome. However, the etiologies of both diabetic retinopathy (DR) and dry eye disease are complex, and their associations with T2D remains to be fully understood. Patient-derived human induced pluripotent stem cells (hiPSCs) enable the generation of disease-specific retinal tissues such as retinal pigment epithelium and lacrimal gland to model disease pathogenesis. Here, we describe the establishment of three hiPSC lines from T2D patients with PDR or dry eye disease.

An important safety concern in the use of human pluripotent stem cells (hPSCs) is tumorigenic risk, because these cells can form teratomas after an in vivo injection at ectopic sites. Several thousands of undifferentiated hPSCs are sufficient to induce teratomas in a mouse model. Thus, it is critical to remove all residue-undifferentiated hPSCs that have teratoma potential before the clinical application of hPSC-derived cells. In this study, our data demonstrated the cytotoxic effects of cardiac glycosides, such as digoxin, lanatoside C, bufalin, and proscillaridin A, in human embryonic stem cells (hESCs). This phenomenon was not observed in human bone marrow mesenchymal stem cells (hBMMSCs). Most importantly, digoxin and lanatoside C did not affect the stem cells’ differentiation ability. Consistently, the viability of the hESC-derived MSCs, neurons, and endothelium cells was not affected by the digoxin and lanatoside C treatment. Furthermore, the in vivo experiments demonstrated that digoxin and lanatoside C prevented teratoma formation. To the best of our knowledge, this study is the first to describe the cytotoxicity and tumor prevention effects of cardiac glycosides in hESCs. Digoxin and lanatoside C are also the first FDA-approved drugs that demonstrated cytotoxicity in undifferentiated hESCs.

The importance of a data exchanging culture accompanied by a supporting bioinformatic system is widely praised as an aid to sustainable development. Yet this is not always implemented as a top-down procedure in every governing environment. Common obstacles include lack of resources, lack of support from decision-makers, and lack of recognition from data-providers. Using citizen science (hereafter CS), which assumes a spirit of public information sharing, we demonstrate how CS can be a critical tool to help database managers overcome this difficulty. CS data contributes to impressively over 70% of the currently 4.5 million openly distributed occurrence data in Taiwan. Although CS projects emerged much earlier in a few taxa, such as Aves and Anura, CS was unknown to the wider public and politicians in the region until 2009. This was probably due to the combination of the popularity of social media and improvements to wifi connections, which brought discoveries and impacts of CS data to the news spotlight. Such cases include roadkill projects that aided rabies-outbreak control, and amateur bird records that helped downscale the conflict between solar energy deployment and migratory wetland bird conservation. These cases also created feedback on the call for more data to be open, an effect that was prominent from project managers in other CS communities, the previously reluctant expert researcher communities, and even placed pressure on data policy of several conservation agencies which previously were not supportive of open data. The inclusion of CS programs is also critical in forming alliances between agencies that were responsible for promoting and building the biodiversity informatics system. Previously, financial and human resources for such systems are split across agencies. However, in terms of building up a cutting edge biodiversity information service platform, or empowerment of human resources to handle the rapidly growing amount of data, joint partnerships across government agencies is then necessary. CS brings the spotlight of government efforts to the people, which is an important strategy to maintain support from top decision-makers and politicians, who mostly rely on public votes in a democratic society. Currently, the national node of the Global Biodiversity Information Facility in Taiwan, the administration for conservation in Taiwan, and the main biodiversity consultancy in Taiwan have teamed up, answering the call for sharing data for a better future. As a tribute to the CS projects, a biodiversity informatics system named Taiwan Biodiversity Network, is now enhancing its ability as a platform to promote data usage and provide technical aid to CS programs. Data visualization projects such as “Coldspots” pointed out regions that lack data, which can be used to decide where to focus efforts for the next field surveys. Online CS data platforms, such as Taiwan Reptile Report Program, are also working to ease the previously intensive efforts that project managers needed to contribute to run event-based monitoring. Combined, these developments form a cultural and technical basis for the implementation of multi-taxa atlas projects, which was made possible by the mainstreaming of open data culture and biodiversity awareness through citizen science projects.

Type 1 diabetes (T1D) is characterized by the autoimmune destruction of insulin-producing β cells. Genetic studies have identified > 60 T1D risk loci that harbor genes with disease-causative alleles. However, determining the biological effects of such loci is often difficult due to limited tissue availability. Disease-specific human induced pluripotent stem cells (hiPSCs) are a valuable resource for modeling T1D pathogenesis. In particular, families with complete disease penetrance offer an opportunity to further dissect T1D risk loci. Here, we describe the generation of three hiPSC lines from a T1D family with sequence variants associated with autoimmunity.

Background & Aim Induced pluripotent stem cells (iPSCs), which can be generated from patients’ somatic cells and grown in cultures maintaining their pluripotency and possessing the unlimited self-renewal capability, have been utilized for developing cell therapeutic strategies, dissecting disease mechanisms and validating drug response. Recent studies imply pluripotent stem cells (PSCs) possess a unique metabolic features and require specific metabolites in maintaining their cell fate. In the current work, we have deciphered the specific metabolites required for maintaining self-renewal expansion of iPSCs. Methods, Results & Conclusion Utilizing RNA-Seq analysis, we showed that, in comparing with fibroblast, ESCs and iPSCs were found to retain the expression of critical enzymes involved in Krebs cycle. We then determined if the specific bioenergetics adaptation in cultures can affect pluripotency acquirement or maintenance. Oct4-GFP(+) iPSCs derived mouse fibroblast were seeded in medium containing either 4500mM Glucose (high glucose) with or without Oligomycin (mitochondrial ATPase inhibitor), 500mM Glucose (low glucose) and 0mM Glucose (no glucose) with or without pyruvate (to be utilized in TCA cycles). We found that depletion of glucose resulted in reduced growth of Oct4-GFP(+) iPSC colonies. In contrast, addition of pyruvate could rescue the growth of Oct4-GFP(+) iPSC colonies suggesting the retaining mitochondrial respiration may aid self-renewal expansion of pluripotent stem cells. The further analysis revealed that mouse and human ESCs/iPSCs had evaluated level of GLUT5 & KHK suggesting pluripotent stem cells can utilize fructose efficiently. We further validated that fructose substitution was sufficient to maintain the self-renewal growth of ESCs/iPSCs. Importantly, fructose substitution was found to enhance generation of iPSCs from Yamanaka factor mediated fibroblast reprogramming possibly via selectively suppressing the growth of partial reprogrammed cells and upregulating alpha 2,6-sialylation as sialyltransferase ST6Gal1 is known to play an crucial role in regulating pluripotency. In summary, the current work elucidated that the specific bioenergetics adaptation in cultures linking to pluripotency maintenance and identified ESCs/iPSCs can utilize fructose efficiently. Fructose substitution can therefore be used to enhance derivation of iPSCs.

Transcriptionally non-co-linear (NCL) transcripts can originate from trans-splicing (trans-spliced RNA; ‘tsRNA’) or cis-backsplicing (circular RNA; ‘circRNA’). While numerous circRNAs have been detected in various species, tsRNAs remain largely uninvestigated. Here, we utilize integrative transcriptome sequencing of poly(A)- and non-poly(A)-selected RNA-seq data from diverse human cell lines to distinguish between tsRNAs and circRNAs. We identified 24,498 NCL events and found that a considerable proportion (20–35%) of them arise from both tsRNAs and circRNAs, representing extensive alternative trans-splicing and cis-backsplicing in human cells. We show that sequence generalities of exon circularization are also observed in tsRNAs. Recapitulation of NCL RNAs further shows that inverted Alu repeats can simultaneously promote the formation of tsRNAs and circRNAs. However, tsRNAs and circRNAs exhibit quite different, or even opposite, expression patterns, in terms of correlation with the expression of their co-linear counterparts, expression breadth/abundance, transcript stability, and subcellular localization preference. These results indicate that tsRNAs and circRNAs may play different regulatory roles and analysis of NCL events should take the joint effects of different NCL-splicing types and joint effects of multiple NCL events into consideration. This study describes the first transcriptome-wide analysis of trans-splicing and cis-backsplicing, expanding our understanding of the complexity of the human transcriptome.

Androgen receptor (AR) is a steroid hormone receptor that functions as a transcription factor for regulating cell growth and survival. Aberrant AR function becomes a risk factor for promoting the progression of prostate cancer (PCa). In this study, we examined the roles of proline-rich tyrosine kinase 2 (PYK2) and ribosomal S6 kinase 1 (S6K1) in regulating AR expression and activity and growth properties in PCa cells. Compared with normal prostate tissues, PCa tumors exhibited high levels of PYK2 and S6K1 expression. Furthermore, the expression levels of PYK2 and S6K1 were significantly correlated with nuclear AR expression in PCa tissues. We further found the association between PYK2, S6K1, and AR in their protein expression and phosphorylation levels among normal prostate PZ-HPV-7 cells and prostate cancer LNCaP and 22Rv1 cells. Overexpression of the wild-type PYK2 in PZ-HPV-7 and LNCaP cells promoted AR and S6K1 expression and phosphorylation as well as enhanced cell growth. In contrast, expression of the mutated PYK2 or knockdown of PYK2 expression in LNCaP or 22Rv1 cells caused reduced expression or phosphorylation of AR and S6K1 as well as retarded cell growth. Under an androgen-deprived condition, PYK2-promoted AR expression and phosphorylation and PSA production in LNCaP cells can be abolished by knocking down S6K1 expression. In summary, our data suggested that PYK2 via S6K1 activation modulated AR function and growth properties in PCa cells. Thus, PYK2 and S6K1 may potentially serve as therapeutic targets for PCa treatment.