Cosmic R-string, R-tube and Vacuum Instability

We show that a cosmic string associated with spontaneous $U(1)_R$ symmetry breaking gives a constraint for supersymmetric model building. In some models, the string can be viewed as a tube-like domain wall with a winding number interpolating a false vacuum and a true vacuum. Such string causes inhomogeneous decay of the false vacuum to the true vacuum via rapid expansion of the radius of the tube and hence its formation would be inconsistent with the present Universe. However, we demonstrate that there exist metastable solutions which do not expand rapidly. Furthermore, when the true vacua are degenerate, the structure inside the tube becomes involved. As an example, we show a "bamboo"-like solution, which suggests a possibility observing an information of true vacua from outside of the tube through the shape and the tension of the tube.Comment: 28 pages, 17 figures, v2: references added, improved arguments in sec 3.5.

Solution-processed amorphous niobium oxide as a novel electron collection layer for inverted polymer solar cells

Amorphous niobium oxide (NbOx) as an electron collection layer in inverted polymer solar cells was prepared by a solution process. The power conversion efficiency of inverted polymer solar cells based on a blend of poly(3-hexylthiophene) and [6,6]-phenyl C61 butyric acid methyl ester was improved to 2.22% by inserting an NbOx layer between the active layer and indium tin oxide electrode. An energy level diagram of component materials in the inverted polymer solar cell indicated that the NbOx layer works as both an electron collection layer and hole blocking layer in polymer solar cells

Effects of Cerclage Cabling on Preventing Periprosthetic Femoral Fractures When Using Cementless Stems for Unstable Femoral Neck Fractures

Iwasa M., Ando W., Takashima K., et al. Effects of Cerclage Cabling on Preventing Periprosthetic Femoral Fractures When Using Cementless Stems for Unstable Femoral Neck Fractures. Journal of Arthroplasty , (2024); https://doi.org/10.1016/j.arth.2024.04.085.Background: Periprosthetic femoral fractures (PFFs) are serious complications in hip arthroplasty for femoral neck fractures. The rates of intraoperative (iPFFs) and postoperative PFFs (pPFFs) are higher in cementless stem cases than in cemented cases. This study aimed to investigate the effects of cerclage cabling on PFF prevention in cementless arthroplasty for femoral neck fractures. Methods: This retrospective study included 329 consecutive patients who underwent hip arthroplasty using a cementless stem for femoral neck fractures. A total of 159 and 170 patients were in the non-cabling and cabling groups, respectively. Patient characteristics were comparable in both groups. The PFF occurrence (iPFF and pPFF) rates, reoperation rates, operative time, and blood loss volume were compared between the groups. Results: The iPFF rate was significantly higher in the noncabling group (6.3%) than in the cabling group (0%, P <.001). The rate of pPFF was significantly higher in the non-cabling group (5.1%) than in the cabling group (0.6%; P =.016). All patients in the non-cabling group required reoperation (5.1%), whereas the patient in the cabling group was an ambulatory case and required no reoperation (0%, P =.003). No significant difference in either operative time or blood loss volume was observed between the non-cabling (50 minutes, 133 mL) and cabling (52 minutes, P =.244; 149 mL, P =.212, respectively) groups. Conclusions: When a cementless stem is used to treat unstable femoral neck fractures, cerclage cabling effectively prevents iPPF and pPPF without increasing surgical time or blood loss volume

Multidrug Sensitive Yeast Strains, Useful Tools for Chemical Genetics

The budding yeast Saccharomyces cerevisiae is a useful eukaryote model organism for application to chemical biology studies, for example, drug screening, drug evaluation, and target identification. To use yeast for chemical biology research, however, it has been necessary to construct yeast strains suitable for various compounds because of their high drug resistance. Hence, the deletion of all multidrug resistance genes except for those that are important for viability and for genetic experiments/manipulation could increase the drug sensitivity without influencing the transformation, mating, or sporulation efficiency. There are two major factors conferring multidrug resistance in S. cerevisiae: one is the drug efflux system and the other is the permeability barrier. We therefore constructed a strain which shows high sensitivity to multiple drugs by disrupting the drug efflux system using ATP-binding cassette transporters and suppressing the membrane barrier system by introducing an ERG6-inducible system. In this review, we discuss the construction of our multidrug-sensitive yeast strains and their application in chemical biology

Clinical evaluation of suture materials for transtibial pullout repair of medial meniscus posterior root tear

Background: There are no recommendations for specific suture materials in transtibial pullout repair of medial meniscus posterior root tears. This study aimed to evaluate the clinical outcomes of transtibial pullout repair of medial meniscus posterior root tears using ultrahigh-molecular-weight polyethylene sutures and suture tape. Methods: We retrospectively reviewed the data of 36 patients (27 women and 9 men, mean age 64.1 years) who had undergone transtibial pullout repair of medial meniscus posterior root tears between November 2018 and December 2019. Two groups of 18 patients each received either two different cord-like sutures or suture tape. Clinical parameters were assessed preoperatively and on second-look arthroscopy (mean postoperative period 12 months). The meniscal healing status was assessed using a previously published scoring system (ranging from 0 to 10), and the incidence rate of suture cut-out was assessed on second-look arthroscopy. Results: All clinical scores significantly improved in both groups, with no significant between-group differences on second-look arthroscopy. The arthroscopic meniscal healing scores significantly differed between sutures (mean 6.7 points) and suture tape (mean 7.4 points; p = 0.044). No significant between-group difference in the suture cut-out rate was observed. Conclusions: This study found no significant differences in the clinical outcomes between ultrahigh-molecular-weight polyethylene sutures and suture tape. Favorable clinical outcomes were obtained using both types of suture; however, the usefulness of suture tape appears to be limited

An in vitro three-dimensional co-culture system for ameloblastoma modelling

Ameloblastoma, the most clinically significant odontogenic epithelial tumor, is a locally-invasive and destructive lesion in the jawbones. However, the nature of this infiltrativeness and destructive behavior remains ill-understood. To address this, we established an in vitro three-dimensional (3D) co-culture system to simulate an amelobastoma disease model aimed at investigating the interactions between tumor cells and osteoblasts. Osteoblastic cell lines (KUSA/A1 and MC3T3-E1) and one stromal cell line (ST2) were separately co-seeded with ameloblastoma-derived cell line (AM-1) in a collagen scaffold (representing the extracellular bone matrix) and incubated with mineralization medium. Immunohistochemistry, double immunofluorescence and mineralization assay were performed. Only AM-1/KUSA-A1 co-culture showed a significant increase in AM-1 cell count, suggesting that heterotypic cell-cell interaction promotes tumoral cell growth, while formation of visible AM-1 epithelial nest-like structures resembling ameloblastoma cells in their native state, suggest morphodifferentiation. A RANK-high, RANKL-low and osteoprotegerin-low immunoprofile in co-culture AM-1 cells implies deregulated osteoclastogenesis. Mineralization assays showed diminished calcification in AM-1/KUSA-A1 co-culture extracellular matrix suggesting an altered local bone metabolism. In contrast, KUSA/A1 monocultures showed abundant extracellular matrix calcification. Taken together, these results suggest that a 3D co-culture system as an amelobastoma disease model provides insights that bidirectional ameloblastoma-osteoblastic interactions might play a role in modulating tumor growth and osteoclastogenesis

Dietary Patterns and Risk of Colorectal Cancer Subtypes Classified by Fusobacterium nucleatum in Tumor Tissue

Importance—Fusobacterium nucleatum appears to play a role in colorectal carcinogenesis through suppression of host immune response to tumor. Evidence also suggests that diet influences intestinal F. nucleatum. However, the role of F. nucleatum in mediating the relationship between diet and the risk of colorectal cancer is unknown. Objective—To test the hypothesis that the associations of prudent diets (rich in whole grains and dietary fiber) and Western diets (rich in red and processed meat, refined grains, and desserts) with colorectal cancer risk may differ according to the presence of F. nucleatum in tumor tissue. Design—Prospective cohort study. Setting—The Nurses’ Health Study (1980–2012) and the Health Professionals Follow-up Study (1986–2012). Participants—121,700 US female nurses and 51,529 US male health professionals aged 30 to 55 years and 40 to 75 years, respectively, at enrollment. Exposures—Prudent and Western dietary patterns. Main Outcomes and Measures—Incidence of colorectal carcinoma subclassified by F. nucleatum status in tumor tissue, determined by quantitative polymerase chain reaction. Results—We documented 1,019 incident colon and rectal cancer cases with available F. nucleatum data among predominantly white 137,217 individuals over 26–32 years of follow-up encompassing 3,643,562 person-years. The association of prudent diet with colorectal cancer significantly differed by tissue F. nucleatum status (Pheterogeneity = .01). Prudent diet score was associated with a lower risk of F. nucleatum-positive cancers [Ptrend = .003; multivariable hazard ratio of 0.43 (95% confidence interval 0.25–0.72) for the highest vs. the lowest prudent score quartile], but not with F. nucleatum-negative cancers (Ptrend = .47). Dietary component analyses suggested possible differential associations for the cancer subgroups according to intakes of dietary fiber (Pheterogeneity = .02). There was no significant heterogeneity between the subgroups according to Western dietary pattern scores (Pheterogeneity = .23). Conclusions and Relevance—Prudent diets rich in whole grains and dietary fiber are associated with a lower risk for F. nucleatum-positive colorectal cancer but not F. nucleatum-negative cancer, supporting a potential role for intestinal microbiota in mediating the association between diet and colorectal neoplasms