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Surface-enhanced Raman scattering (SERS) spectroscopy is an ultra-sensitive analytical method with the powerful signal-molecule detection capability. Coupling with the polydimethylsiloxane (PDMS) material, SERS can be enabled on a polymeric substrate for fast-developing bio-compatible sensing applications. However, due to PDMS’s high viscosity, conventional PDMS-SERS substrates are typically thick and stiff, limiting their freedom for engineering flexible micro/nano functioning devices. To address this issue, we propose to adopt a low viscosity decamethylcyclopentasiloxane (D5) solvent as a diluent solution. Via controlling the mixture ratio of D5 and PDMS and the spin-coating speed for deposition, this method resulted in a film of a well-defined thickness from sub-millimeter down to a 100 nm scale. Furthermore, thanks to the unsaturated Si-H chemical bonds in the PDMS curing agent, the PDMS film could effectively reduce the Ag+ ions to Ag nanoparticles (NPs) directly bonding onto the substrate surface uniformly. Via adjusting the size and density of the AgNPs through reaction temperature and time, strong SERS was achieved and verified using R6G with the detection limit down to 0.1 ppm, attributed to the AgNPs’ plasmonic enhancement effect.

Primary ovarian insufficiency (POI) and polycystic ovarian syndrome are ovarian diseases causing infertility. Although there is no effective treatment for POI, therapies for polycystic ovarian syndrome include ovarian wedge resection or laser drilling to induce follicle growth. Underlying mechanisms for these disruptive procedures are unclear. Here, we explored the role of the conserved Hippo signaling pathway that serves to maintain optimal size across organs and species. We found that fragmentation of murine ovaries promoted actin polymerization and disrupted ovarian Hippo signaling, leading to increased expression of downstream growth factors, promotion of follicle growth, and the generation of mature oocytes. In addition to elucidating mechanisms underlying follicle growth elicited by ovarian damage, we further demonstrated additive follicle growth when ovarian fragmentation was combined with Akt stimulator treatments. We then extended results to treatment of infertility in POI patients via disruption of Hippo signaling by fragmenting ovaries followed by Akt stimulator treatment and autografting. We successfully promoted follicle growth, retrieved mature oocytes, and performed in vitro fertilization. Following embryo transfer, a healthy baby was delivered. The ovarian fragmentation-in vitro activation approach is not only valuable for treating infertility of POI patients but could also be useful for middle-aged infertile women, cancer patients undergoing sterilizing treatments, and other conditions of diminished ovarian reserve.

Heart disease is the most common cause of death in developed countries, but the medical treatments for heart failure remain limited. In this context, the development of cardiac regeneration therapy for severe heart failure is important. Owing to their unique characteristics, including multiple differentiation and infinitive self-renewal, pluripotent stem cells can be considered as a novel source for regenerative medicine. Janus kinase/signal transducer and activator of transcription 3 (JAK/STAT3) signaling plays critical roles in the induction, maintenance, and differentiation of pluripotent stem cells. In the heart, JAK/STAT3 signaling has diverse cellular functions, including myocardial differentiation, cell cycle re-entry of matured myocyte after injury, and anti-apoptosis in pathological conditions. Therefore, regulating STAT3 activity has great potential as a strategy of cardiac regeneration therapy. In this review, we summarize the current understanding of STAT3, focusing on stem cell biology and pathophysiology, as they contribute to cardiac regeneration therapy. We also introduce a recently reported therapeutic strategy for myocardial regeneration that uses engineered artificial receptors that trigger endogenous STAT3 signal activation.

Induced pluripotent stem cells (iPSCs) were first established from differentiated somatic cells by gene introduction of key transcription factors, OCT4, SOX2, KLF4, and c-MYC, over a decade ago. Although iPSCs can be applicable for regenerative medicine, disease modeling and drug screening, several issues associated with the utilization of iPSCs such as low reprogramming efficiency and the risk of tumorigenesis, still need to be resolved. In addition, the molecular mechanisms involved in the somatic cell reprogramming to pluripotency are yet to be elucidated. Compared with their somatic counterparts, pluripotent stem cells, including embryonic stem cells and iPSCs, exhibit a high rate of glycolysis akin to aerobic glycolysis in cancer cells. This is known as the Warburg effect and is essential for maintaining stem cell properties. This unique glycolytic metabolism in iPSCs can provide energy and drive the pentose phosphate pathway, which is the preferred pathway for rapid cell proliferation. During reprogramming, somatic cells undergo a metabolic shift from oxidative phosphorylation (OXPHOS) to glycolysis trigged by a transient OXPHOS burst, resulting in the initiation and progression of reprogramming to iPSCs. Metabolic intermediates and mitochondrial functions are also involved in the epigenetic modification necessary for the process of iPSC reprogramming. Among the key regulatory molecules that have been reported to be involved in metabolic shift so far, hypoxia-inducible factor 1 (HIF1) controls the transcription of many target genes to initiate metabolic changes in the early stage and maintains glycolytic metabolism in the later phase of reprogramming. This review summarizes the current understanding of the unique metabolism of pluripotent stem cells and the metabolic shift during reprogramming, and details the relevance of HIF1 in the metabolic shift.

Although multiple follicles are present in mammalian ovaries, most of them remain dormant for years or decades. During reproductive life, some follicles are activated for development. Genetically modified mouse models with oocyte-specific deletion of genes in the PTEN-PI3K-Akt-Foxo3 pathway exhibited premature activation of all dormant follicles. Using an inhibitor of the Phosphatase with TENsin homology deleted in chromosome 10 (PTEN) phosphatase and a PI3K activating peptide, we found that short-term treatment of neonatal mouse ovaries increased nuclear exclusion of Foxo3 in primordial oocytes. After transplantation under kidney capsules of ovariectomized hosts, treated follicles developed to the preovulatory stage with mature eggs displaying normal epigenetic changes of imprinted genes. After in vitro fertilization and embryo transfer, healthy progeny with proven fertility were delivered. Human ovarian cortical fragments from cancer patients were also treated with the PTEN inhibitor. After xeno-transplantation to immune-deficient mice for 6 months, primordial follicles developed to the preovulatory stage with oocytes capable of undergoing nuclear maturation. Major differences between male and female mammals are unlimited number of sperm and paucity of mature oocytes. Thus, short-term in vitro activation of dormant ovarian follicles after stimulation of the PI3K-Akt pathway allows the generation of a large supply of mature female germ cells for future treatment of infertile women with a diminishing ovarian reserve and for cancer patients with cryo-preserved ovaries. Generation of a large number of human oocytes also facilitates future derivation of embryonic stem cells for regenerative medicine.

High-entropy alloys (HEAs) comprise a novel class of scientifically and technologically interesting materials. Among these, equatomic CrMnFeCoNi with the face-centered cubic (FCC) structure is noteworthy because its ductility and strength increase with decreasing temperature while maintaining outstanding fracture toughness at cryogenic temperatures. Here we report for the first time by single-crystal micropillar compression that its bulk room temperature critical resolved shear stress (CRSS) is ~33–43 MPa, ~10 times higher than that of pure nickel. CRSS depends on pillar size with an inverse power-law scaling exponent of –0.63 independent of orientation. Planar ½ < 110 > {111} dislocations dissociate into Shockley partials whose separations range from ~3.5–4.5 nm near the screw orientation to ~5–8 nm near the edge, yielding a stacking fault energy of 30 ± 5 mJ/m 2 . Dislocations are smoothly curved without any preferred line orientation indicating no significant anisotropy in mobilities of edge and screw segments. The shear-modulus-normalized CRSS of the HEA is not exceptionally high compared to those of certain concentrated binary FCC solid solutions. Its rough magnitude calculated using the Fleischer/Labusch models corresponds to that of a hypothetical binary with the elastic constants of our HEA, solute concentrations of 20–50 at.%, and atomic size misfit of ~4%.

Automated medical history-taking systems that generate differential diagnosis lists have been suggested to contribute to improved diagnostic accuracy. However, the effect of these systems on diagnostic errors in clinical practice remains unknown. This study aimed to assess the incidence of diagnostic errors in an outpatient department, where an artificial intelligence (AI)-driven automated medical history-taking system that generates differential diagnosis lists was implemented in clinical practice. We conducted a retrospective observational study using data from a community hospital in Japan. We included patients aged 20 years and older who used an AI-driven, automated medical history-taking system that generates differential diagnosis lists in the outpatient department of internal medicine for whom the index visit was between July 1, 2019, and June 30, 2020, followed by unplanned hospitalization within 14 days. The primary endpoint was the incidence of diagnostic errors, which were detected using the Revised Safer Dx Instrument by at least two independent reviewers. To evaluate the effect of differential diagnosis lists from the AI system on the incidence of diagnostic errors, we compared the incidence of these errors between a group where the AI system generated the final diagnosis in the differential diagnosis list and a group where the AI system did not generate the final diagnosis in the list; the Fisher exact test was used for comparison between these groups. For cases with confirmed diagnostic errors, further review was conducted to identify the contributing factors of these errors via discussion among three reviewers, using the Safer Dx Process Breakdown Supplement as a reference. A total of 146 patients were analyzed. A final diagnosis was confirmed for 138 patients and was observed in the differential diagnosis list from the AI system for 69 patients. Diagnostic errors occurred in 16 out of 146 patients (11.0%, 95% CI 6.4%-17.2%). Although statistically insignificant, the incidence of diagnostic errors was lower in cases where the final diagnosis was included in the differential diagnosis list from the AI system than in cases where the final diagnosis was not included in the list (7.2% vs 15.9%, P=.18). The incidence of diagnostic errors among patients in the outpatient department of internal medicine who used an automated medical history-taking system that generates differential diagnosis lists seemed to be lower than the previously reported incidence of diagnostic errors. This result suggests that the implementation of an automated medical history-taking system that generates differential diagnosis lists could be beneficial for diagnostic safety in the outpatient department of internal medicine.

Operative treatment is an option for fractures when the fracture is unstable or the patient wishes to return early to daily life or social activities. Metal plates such as titanium and stainless steel are often used in fracture surgery, but the metal plate lacks bone-healing activity and is not bioabsorbable, requiring a second surgery to remove it after bone union. Here we show that a magnesium (Mg) plate made from an alloy of yttrium, zinc, and aluminum with magnesium as the main component in a long-period stacking ordered structure promotes bone formation in a rabbit tibia fracture model and is also bioabsorbable. We show that the Mg plate significantly promoted bone and callus formation compared to a titanium plate in the rabbit tibia fracture model. Moreover, the Mg plate was mostly bioabsorbed once bone union was achieved, but rabbits showed no evidence of biotoxic effects, such as weight loss or increased blood magnesium levels. We also demonstrate that treatment with exogenous magnesium significantly enhanced calcium deposition in an in vitro osteoblast culture system. Magnesium is an essential element, and its radiolucency facilitates observation of the fracture site during Mg plate fixation, while its lack of magnetic properties allows its use in patients who require MRI scans. Accordingly, we propose that a use of a Mg plate could be beneficial in treating bone fracture.

Bone morphogenetic protein 9 (BMP9)/BMP10-ALK1 receptor signaling is essential for endothelial differentiation and vascular morphogenesis. Mutations in ALK1/ACVRL1 and other signal-related genes are implicated in human vascular diseases, and the Alk1/Acvrl1 deletion in mice causes severe impairment of vascular formation and embryonic lethality. In the microarray screen to search for novel downstream genes of ALK1 signaling, we found that the mRNA and protein expression of serum/glucocorticoid-regulated kinase 1 (SGK1) was rapidly up-regulated by the BMP9 stimulation of cultured human endothelial cells. The increase in SGK1 mRNA was completely blocked by the transcriptional inhibitor actinomycin D and significantly suppressed by the siRNA treatment against the co-SMAD transcription factor SMAD4. Upon the BMP9 treatment of endothelial cells, phosphorylated SMAD1/5/9 bound to a consensus site upstream of the SGK1 gene, which was necessary for BMP9-dependent increment of the luciferase reporter activity driven by the SGK1 proximal enhancer. The Sgk1 mRNA expression in mouse embryos was enriched in vascular endothelial cells at embryonic day 9.0–9.5, at which Sgk1 null mice showed embryonic lethality due to abnormal vascular formation, and its mRNA as well as protein expression was clearly reduced in Alk1/Acvrl1 null embryos. These results indicate that SGK1 is a novel target gene of BMP9/BMP10-ALK1 signaling in endothelial cells and further suggest a possibility that down-regulation of the Sgk1 expression may be involved in the mechanisms of vascular defects by the ALK1 signaling deficiency.

Doxorubicin (DXB), an effective anti-cancer drug, is well documented for its cardiotoxicity in the ventricular myocardium. Although DXB-induced cardiomyopathy can cause arrhythmias, its impact on the cardiac conduction system remains unclear. We aimed to investigate whether DXB affects the function and subcellular structure of the sinus node, the primary pacemaking site. C57BL/6 N mice received intraperitoneal injections of DXB at a total dose of 20 mg/kg. DXB treatment resulted in a reduced intrinsic heart rate during both the acute and chronic phases. We also observed DXB-induced downregulation of genes encoding pacemaker channels in both phases and Ca2 + regulators in the chronic phase. Ultrastructural analysis revealed increased mitochondrial fragmentation, chromatin condensation, and a small number of severely damaged cells within the sinus node. These findings suggest that DXB impairs sinus node function, structure, and transcriptional regulation, potentially through mitochondrial and nuclear damage, leading to loss of pacemaker cells. [Display omitted] •Doxorubicin (DXB) reduces the intrinsic heart rate in mice.•DXB induces downregulation of genes encoding heart rate regulators.•DXB triggers mitochondrial and nuclear abnormalities in sinus node cells.•These findings may guide targeted therapies to improve patients’ cardiac outcomes.