Senile osteoporosis has become a worldwide bone disease with the aging of the world population. It increases the risk of bone fracture and seriously affects human health. Unlike postmenopausal ...osteoporosis which is linked to menopause in women, senile osteoporosis is due to aging, hence, affecting both men and women. It is commonly found in people with more than their 70s. Evidence has shown that with age increase, bone marrow stromal cells (BMSCs) differentiate into more adipocytes rather than osteoblasts and undergo senescence, which leads to decreased bone formation and contributes to senile osteoporosis. Therefore, it is necessary to uncover the molecular mechanisms underlying the functional changes of BMSCs. It will benefit not only for understanding the senile osteoporosis development, but also for finding new therapies to treat senile osteoporosis. Here, we review the recent advances of the functional alterations of BMSCs and the related mechanisms during senile osteoporosis development. Moreover, the treatment of senile osteoporosis by aiming at BMSCs is introduced.
The piezoelectric effect of biological piezoelectric materials promotes bone growth. However, the material should be subjected to stress before it can produce an electric charge that promotes bone ...repair and reconstruction conducive to fracture healing. A novel method for in vitro experimentation of biological piezoelectric materials with physiological load is presented. A dynamic loading device that can simulate the force of human motion and provide periodic load to piezoelectric materials when co-cultured with cells was designed to obtain a realistic expression of piezoelectric effect on bone repair. Hydroxyapatite (HA)/barium titanate (BaTiO
) composite materials were fabricated by slip casting, and their piezoelectric properties were obtained by polarization. The d
of HA/BaTiO
piezoelectric ceramics after polarization was 1.3 pC/N to 6.8 pC/N with BaTiO
content ranging from 80% to 100%. The in vitro biological properties of piezoelectric bioceramics with and without cycle loading were investigated. When HA/BaTiO
piezoelectric bioceramics were affected by cycle loading, the piezoelectric effect of BaTiO
promoted the growth of osteoblasts and interaction with HA, which was better than the effect of HA alone. The best biocompatibility and bone-inducing activity were demonstrated by the 10%HA/90%BaTiO
piezoelectric ceramics.
Guided tissue regeneration (GTR) membranes are key materials used to create barriers between soft and bone tissues during bone defect repair; however, single-function barrier GTR membranes cannot ...meet clinical requirements. In this paper, we propose a GTR membrane with drug release, bone guidance, and barrier functions; this membrane is a poly(lactic-co-glycolic acid) (PLGA)/hydroxyapatite (HA) (core)-collagen/amoxicillin (shell) nanofiber membrane fabricated by coaxial electrospinning. The shell of each nanofiber is composed of collagen/amoxicillin to promote wound healing through drug release, and its core is composed of PLGA/HA to block fibroblast growth into bone defects and promote bone growth. The effects of collagen content in the shell spinning solution on drug release time are studied, and results show that the total release time of amoxicillin can reach 40 h when a shell spinning solution containing 4 wt% collagen is used. Mineralization occurs on the nanofiber membrane surface after 8 weeks of degradation, indicating the ability of the membrane to induce apatite deposition. Fibroblasts were also co-cultured on one side of the core/shell nanofiber membranes, and results showed that fibroblasts on the cultured side grew well; moreover, no fibroblasts were observed on the opposite side of the membrane after 48 h of culture. The barrier membrane developed in this work may be applied in the GTR of dental implants and orthopedic transplants.
The purpose of this retrospective study was to demonstrate the safety and feasibility of three-port single-intercostal video-assisted thoracoscopic surgery (SIC-VATS) segmentectomy compared to ...uniportal video-assisted thoracoscopic surgery (UVATS) segmentectomy.
We included 544 patients diagnosed with cT1N0M0 non-small-cell lung cancer (NSCLC) who underwent thoracoscopic segmentectomy between January 2020 and August 2021, including 147 and 397 patients who underwent three-port SIC-VATS and UVATS, respectively. After incorporating preoperative clinical variables, we compared surgical outcomes and perioperative indicators between the two groups by propensity score matching analysis.
After 1:1 propensity score matching, each group comprised 143 patients with no significant differences in baseline demographics and characteristics. There was no significant difference in operative time (p = 0.469), blood loss (p = 0.501), number of dissected lymph nodes (p = 0.228), dwell time of the main chest drain (p = 0.065), hospital stay (p = 0.243), or major complication rate (p = 0.295) between the three-port SIC-VATS and UVATS groups.
The three-port SIC-VATS was as safe and feasible as UVATS for patients who are diagnosed with early-stage NSCLC.
K-means clustering algorithm is one of the most popular technique for clustering in machine learning, however, in the existing k-means clustering algorithm, the ability of the different features and ...the importance of the different data objects are treated equally; the discriminative ability of the different features and the importance of the different data objects cannot be differentiated effectively. In the light of this limitation, this paper put forward an enhanced regularized k-means type clustering algorithm with adaptive weights in which we introduced an adaptive feature weights matrix and an adaptive data weights vector into the objective function of the k-means clustering algorithm and we developed a new objective function with l2-norm regularization to the weights of data objects and features, then we obtained the corresponding scientific updating iterative rules of the weights of the different features, the weights of the different data objects and the cluster centers theoretically. In order to evaluate the performance of the new algorithm put forward, extensive experiments were conducted. Experimental results have indicated that our proposed algorithm can improve the clustering performance significantly and are more effective with respects to three metrics: the successful clustering rate (SCR), normal mutual information (NMI) and RandIndex.
Piezo channels are mechanosensitive ion channels located in the cell membrane and function as key cellular mechanotransducers for converting mechanical stimuli into electrochemical signals. Emerged ...as key molecular detectors of mechanical forces, Piezo channels’ functions in bone have attracted more and more attention. Here, we summarize the current knowledge of Piezo channels and review the research advances of Piezo channels’ function in bone by highlighting Piezo1′s role in bone cells, including osteocyte, bone marrow mesenchymal stem cell (BM-MSC), osteoblast, osteoclast, and chondrocyte. Moreover, the role of Piezo channels in bone diseases is summarized.
To investigate the long-term efficacy of the minimally invasive Ivor Lewis esophagectomy (MIILE) in esophageal squamous cell carcinoma (ESCC) patients, a retrospective comparison of the quality of ...life (QOL) and survival between patients who underwent MIILE and left transthoracic esophagectomy (Sweet approach) was conducted.
A detailed database search identified 614 patients who underwent MIILE and 243 patients who underwent Sweet esophagectomy between January 2011 and December 2017. After propensity score matching, 216 paired cases were selected for statistical analysis. Survival was evaluated with Kaplan-Meier curves or Cox models.
MIILE was associated with a longer duration, less blood loss and more lymph node dissected than Sweet esophagectomy. MIILE patients suffered from less pain, less frequently developed pneumonia, and had fewer postoperative complications. Additionally, MIILE patients began oral intake earlier and had a shorter postoperative hospital stay, and enhanced recovery of QOL. There was no significant difference between the approaches regarding the recurrence pattern, 2-year and 5-year overall survival (OS) or disease-free survival (DFS), except that patients with tumor-node-metastasis (TNM) stage I in the MIILE group demonstrated superior OS and DFS. Pathological TNM stage and postoperative complications were determined to be independent prognostic factors based on the multivariate analysis.
MIILE is a safe and feasible approach for treating ESCC patients. MIILE approach may provide more postoperative advantages, enhanced QOL improvement, and more favorable long-term survival in early stage patients than the Sweet procedure.
The lipid production potentials of 8 microalgal species were investigated. Among these 8 species, the best strain was a dominant bloom-causing dinoflagellate, Prorocentrum donghaiense; this species ...had a lipid content of 49.32% ± 1.99% and exhibited a lipid productivity of 95.47 ± 0.99 mg liter−1 day−1, which was 2-fold higher than the corresponding values obtained for the oleaginous microalgae Nannochloropsis gaditana and Phaeodactylum tricornutum. P. donghaiense, which is enriched in C16:0 and C22:6, is appropriate for commercial docosahexaenoic acid (DHA) production. Nitrogen or phosphorus stress markedly induced lipid accumulation to levels surpassing 75% of the dry weight, increased the C18:0 and C17:1 contents, and decreased the C18:5 and C22:6 contents, and these effects resulted in decreases in the unsaturated fatty acid levels and changes in the lipid properties of P. donghaiense such that the species met the biodiesel specification standards. Compared with the results obtained under N-deficient conditions, the enhancement in the activity of alkaline phosphatase of P. donghaiense observed under P-deficient conditions partly alleviated the adverse effects on the photosynthetic system exerted by P deficiency to induce the production of more carbohydrates for lipogenesis. The supernatant of the algicidal bacterium Paracoccus sp. strain Y42 culture lysed P. donghaiense without decreasing its lipid content, which resulted in facilitation of the downstream oil extraction process and energy savings through the lysis of algal cells. The Y42 supernatant treatment improved the lipid profiles of algal cells by increasing their C16:0, C18:0, and C18:1 contents and decreasing their C18:5 and C22:6 contents, which is favorable for biodiesel production. IMPORTANCE This study demonstrates the high potential of Prorocentrum donghaiense, a dominant bloom-causing dinoflagellate, for lipid production. Compared with previously studied oleaginous microalgae, P. donghaiense exhibit greater potential for practical application due to its higher biomass and lipid contents. Nutrient deficiency and the algicidal bacterium Paracoccus sp. strain Y42 improved the suitability of the lipid profile of P. donghaiense for biodiesel production. Furthermore, Paracoccus sp. Y42 effectively lysed algal cells, which facilitates the downstream oil extraction process for biodiesel production and results in energy savings through the lysing of algal cells. This study provides a more promising candidate for the production of docosahexaenoic acid (DHA) for human nutritional products and of microalgal biofuel as well as a more cost-effective method for breaking algal cells. The high lipid productivity of P. donghaiense and algal cell lysis by algicidal bacteria contribute to reductions in the production cost of microalgal oil.
Cast stainless steels with high strength and toughness are very important for industrial production, but the strengthening methods are very limited. In this study, a novel cast multi-phase stainless ...steel (CMPSS) containing ferrite, martensite and austenite was prepared and its strengthening mechanism was investigated. After solid solution and tempering at 520 °C for 4 h, the yield strength of the sample reaches over 800 MPa, and the total elongation exceeds 13%. This tempering strengthening is mainly achieved by precipitation of the nanoscale Laves phase pinning dislocations in ferrite. However, when prolonging the tempering time or increasing the tempering temperature, the Laves-phase particles precipitate and coarsen along the phase boundary, which seriously damages the strength and toughness of the sample. In addition, high-temperature tempering also leads to a decrease in retained austenite (RA) content by reducing the amount of C and Mn elements in the lath martensite and promotes the precipitation of the R phase (molybdenum-rich intermetallic compound) in ferrite, which is also detrimental to the mechanical properties of CMPSS.
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