Menopause predisposes women to osteoporosis due to declining estrogen levels. This results in a decrease in bone mineral density (BMD) and an increase in fractures. Osteoporotic fractures lead to ...substantial morbidity and mortality, and are considered one of the largest public health priorities by the World Health Organization (WHO). It is therefore essential for menopausal women to receive appropriate guidance for the prevention and management of osteoporosis. The Women’s Health Initiative (WHI) randomized controlled trial first proved hormonal therapy (HT) reduces the incidence of all osteoporosis-related fractures in postmenopausal women. However, the study concluded that the adverse effects outweighed the potential benefits on bone, leading to a significant decrease in HT use for menopausal symptoms. Additionally, HT was not used as first-line therapy for osteoporosis and fractures. Subsequent studies have challenged these initial conclusions and have shown significant efficacy of HT in various doses, durations, regimens, and routes of administration. These studies support that HT improves BMD and reduces fracture risk in women with and without osteoporosis. Furthermore, the studies suggest that low-dose and transdermal HT are less likely associated with the adverse effects of breast cancer, endometrial hyperplasia, coronary artery disease (CAD), and venous thromboembolism (VTE) previously observed in standard-dose oral HT regimens. Given the need for estrogen in menopausal women and evidence supporting the cost effectiveness, safety, and efficacy of HT, we propose that HT should be considered for the primary prevention and treatment of osteoporosis in appropriate candidates. HT should be individualized and the once “lowest dose for shortest period of time” concept should no longer be used. This review will focus on the prior and current studies for various HT formulations used for the prevention and treatment of osteoporosis, exploring the safety profile of low-dose and transdermal HT that have been shown to be safer than oral standard-dose HT.
Osteoclasts are cells derived from bone marrow macrophages and are important in regulating bone resorption during bone homeostasis. Understanding what drives osteoclast differentiation and activity ...is important when studying diseases characterized by heightened bone resorption relative to formation, such as osteoporosis. In the last decade, studies have indicated that reactive oxygen species (ROS), including superoxide and hydrogen peroxide, are crucial components that regulate the differentiation process of osteoclasts. However, there are still many unanswered questions that remain. This review will examine the mechanisms by which ROS can be produced in osteoclasts as well as how it may affect osteoclast differentiation and activity through its actions on osteoclastogenesis signaling pathways. In addition, the contribution of ROS to the aging-associated disease of osteoporosis will be addressed and how targeting ROS may lead to the development of novel therapeutic treatment options.
Craniofacial hard tissue mainly includes craniofacial bone and tooth, which is one of the important parts of the mouth-jaw system. Congenital aplasia, tumors and trauma can cause large craniofacial ...hard tissue defects, which are detrimental to the facial appearance and function of patients, and affect the physical and mental health of patients. Histone acetylation modification is the earliest and most widely studied histone modification, which is an epigenetic modification mechanism jointly regulated by histone acetyltransferase and histone deacetylase. In this paper, we will review the research progress of histone acetylation mediated by histone acetyltransferase and histone deacetylase in the development and regeneration of craniofacial hard tissue.
Large-scale, highly integrated and low-power-consuming hardware is becoming progressively more important for realizing optical neural networks (ONNs) capable of advanced optical computing. ...Traditional experimental implementations need N
units such as Mach-Zehnder interferometers (MZIs) for an input dimension N to realize typical computing operations (convolutions and matrix multiplication), resulting in limited scalability and consuming excessive power. Here, we propose the integrated diffractive optical network for implementing parallel Fourier transforms, convolution operations and application-specific optical computing using two ultracompact diffractive cells (Fourier transform operation) and only N MZIs. The footprint and energy consumption scales linearly with the input data dimension, instead of the quadratic scaling in the traditional ONN framework. A ~10-fold reduction in both footprint and energy consumption, as well as equal high accuracy with previous MZI-based ONNs was experimentally achieved for computations performed on the MNIST and Fashion-MNIST datasets. The integrated diffractive optical network (IDNN) chip demonstrates a promising avenue towards scalable and low-power-consumption optical computational chips for optical-artificial-intelligence.
Abstract Objectives Many studies have shown that insomnia is a common problem among university students, but there are wide variations in the prevalence of insomnia. In this systematic review, we ...aimed to explore the prevalence of insomnia among university students using scientific and conclusive methods. Study design A systematic review is designed to analyze the studies reporting on prevalence of insomnia among university students. Methods Systemic searches were conducted in PubMed, BioMed Central, EBSCO, ScienceDirect, Ovid LWW and Medline databases between January 2000 and July 2014, The Meta analyst software was used to calculate the prevalence rate of each study, the pooled means of prevalence rates and 95% CIs across studies were then calculated and presented. Results Seven articles that met the inclusion and exclusion criteria were selected. The overall sample size in the current review was 16,478, with a minimum of 219 and a maximum of 10,322. The prevalence rates of the seven studies ranged between 9.4% (95%CI 8.8–10.0%) and 38.2% (95% CI 35.4–41.1%). Overall, the total students studied with a weighted mean prevalence of 18.5% (95% CI 11.2–28.8%), considerably higher than rates of 7.4% (95% CI 5.8–9.0%) reported in general population. Conclusions This review emphasized that insomnia prevalence in university students is considerably higher than that in general population, suggested that more attention should be paid to insomnia in university students.
Developing efficient catalysts for the oxygen reduction reaction (ORR) to reduce cathode Pt loading without sacrificing the performance has been under intensive research. Herein, by using density ...functional theory calculations, the activity and stability of a Pt monolayer supported on Pd
3
Al(111) as the ORR catalyst have been systematically studied. The simulations demonstrate that due to alloying, the ORR intermediates bind weakly on Pt/Pd
3
Al(111) with optimal adsorption energy of O and OH. By considering the elemental ORR steps, the ORR mechanism is predicted to be an OOH dissociation mechanism. The rate determining step is OOH dissociation with a reaction barrier of 0.37 eV, lower than the corresponding value on Pt/Pt
3
Al(111) and Pt(111), indicating the superior activity of Pt/Pd
3
Al(111). Even considering the unfeasible H adsorption under high potential, the ORR mechanism on Pt/Pd
3
Al(111) would proceed
via
O
2
hydration, OOH hydration, H
2
O formation, and H
2
O desorption, indicating a good ORR electrocatalyst. Furthermore, stability was evaluated by calculating the alloy formation energy and the electrochemical potential shift of surface Pt dissolution. The exceptionally negative alloy formation energy of Pd
3
Al and the positive dissolution potential shift of the surface Pt atoms show the enhanced durability of Pt/Pd
3
Al(111). The improved activity, in combination with its enhanced stability, makes the novel ternary alloy electrocatalyst very promising for development of new cathode catalysts for fuel cells.
Developing efficient catalysts for the oxygen reduction reaction (ORR) to reduce cathode Pt loading without sacrificing the performance has been under intensive research.
In this work, zinc was incorporated into TiO₂ coatings on titanium by plasma electrolytic oxidation to obtain the implant with good bacterial inhibition ability and bone-formability. The porous and ...nanostructured Zn-incorporated TiO₂ coatings are built up from pores smaller than 5μm and grains 20–100nm in size, in which the element Zn exists as ZnO. The results obtained from the antibacterial studies suggest that the Zn-incorporated TiO₂ coatings can greatly inhibit the growth of both Staphylococcus aureus and Escherichia coli, and the ability to inhibit bacteria can be improved by increasing the Zn content in the coatings. Moreover, the in vitro cytocompatibility evaluation demonstrates that the adhesion, proliferation and differentiation of rat bone marrow stem cells (bMSC) on Zn-incorporated coatings are significantly enhanced compared with Zn-free coating and commercially pure Ti plate, and no cytotoxicity appeared on any of the Zn-incorporated TiO₂ coatings. Moreover, bMSC express higher level of alkaline phosphatase activity on Zn-incorporated TiO₂ coatings and are induced to differentiate into osteoblast cells. The better antibacterial activity, cytocompatibility and the capability to promote bMSC osteogenic differentiation of Zn-incorporated TiO₂ coatings may be attributed to the fact that Zn ions can be slowly and constantly released from the coatings. In conclusion, innovative Zn-incorporated TiO₂ coatings on titanium with excellent antibacterial activity and biocompatibility are promising candidates for orthopedic and dental implants.
Summary
Our study demonstrated a high incidence of recollapse of the augmented vertebrae after PVP treatment for OVCFs. A risk score based on all significant factors can predict the rate of ...recollapse and gain clinical benefits to prevent recollapse in patients at high risk.
Background
Recollapse of the augmented vertebrae after percutaneous vertebroplasty (PVP) treatment for osteoporotic vertebral compression fractures (OVCFs) has obtained much attention. However, little is known about risk factors and score for recollapse of the augmented vertebrae.
Objective
To determine risk factors and furthermore develop a risk score related to recollapse of the augmented vertebrae after PVP treatment for OVCFs.
Methods
Patients who were treated with PVP for single OVCFs and met this study’s inclusion criteria were retrospectively reviewed. The follow-up period was at least 2 years. Associations of recollapse with co-variates (age, gender, bone mass density BMD with a T-score, fracture level, intravertebral cleft IVC, fracture type, cement volume, cement leakage, leakage into a disc, cement distribution pattern, Non-PMMA-endplate-contact NPEC, preoperative fracture severity, reduction rate RR, reduction angle RA) were analyzed and a risk score for recollapse was further developed to predict recollapse.
Results
A total of 152 patients were included. Recollapse group was found in 42 (27.6%) patients. Preoperative IVC, solid lump cement distribution pattern, more RR (a cutoff value of 7%) and larger RA (a cutoff value of 3°) was significantly associated with increased risk for recollapse of the augmented vertebrae. A risk score was developed based on the number of risk factors present in each patient. Patients with a score of 4 had an approximately ninefold increased risk of developing recollapse over patients with a score of 0. The receiver operating characteristic curve of the risk score generated an area under the curve of 0.899 (95% CI 0.642–0.836,
P
= 0.000).
Conclusion
A risk score based on preoperative IVC, cement distribution pattern, reduction rate, and reduction angle predicts the rate of recollapse. Additional studies should aim to validate this score and inspect clinical benefits of recollapse prophylaxis in patients at high risk.
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