S-Adenosyl-l-Methionine Alleviates the Senescence of MSCs Through the PI3K/AKT/FOXO3a Signaling Pathway.

Cellular senescence significantly affects the proliferative and differentiation capacities of mesenchymal stem cells (MSCs). Identifying key regulators of senescence and exploring potential intervention strategies, including drug-based approaches, are active areas of research. In this context, S-adenosyl-l-methionine (SAM), a critical intermediate in sulfur amino acid metabolism, emerges as a promising candidate for mitigating MSC senescence. In a hydrogen peroxide-induced MSC aging model (100 µM for 2 hours), SAM (50 and 100 µM) was revealed to alleviate the senescence of MSCs, and also attenuated the level of reactive oxygen species and enhanced the adipogenic and osteogenic differentiation in senescent MSCs. In a premature aging mouse model (subcutaneously injected with 150 mg/kg/day d-galactose in the neck and back for 7 weeks), SAM (30 mg/kg/day by gavage for 5 weeks) was shown to delay the overall aging process while increasing the number and thickness of bone trabeculae in the distal femur. Mechanistically, activation of PI3K/AKT signaling and increased phosphorylation of forkhead box O3 (FOXO3a) was proved to be associated with the antisenescence role of SAM. These findings highlight that the PI3K/AKT/FOXO3a axis in MSCs could play a crucial role in MSCs senescence and suggest that SAM may be a potential therapeutic drug for MSCs senescence and related diseases.

Low-Toxicity Self-Photosensitized Biohybrid Systems for Enhanced Light-Driven H2 Production.

Nanoparticles (NPs) represent a potential optoelectronic source capable of significantly boosting hydrogen production; however, their inevitable cytotoxicity may lead to oxidative damage of bacterial cell membranes. In this study, we employed non-photosynthetic Escherichia coli K-12 as a model organism and utilized self-assembled cadmium sulfide (CdS) nanoparticles to construct a low-toxicity and hydrogen-production-enhancing self-photosensitive hybrid system. To mitigate the cytotoxicity of CdS NPs and synthesize biocompatible CdS NPs on the cell surface, we employed engineered E. coli (efeB/OE) for bioremediation, achieving this goal through the overexpression of the peroxidase enzyme (EfeB). A comparative analysis with E. coli-CdS revealed a significant downregulation of genes encoding oxidative stress proteins in efeB/OE-CdS post-irradiation. Atomic force microscopy (AFM) confirmed the stability of bacterial cell membranes. Due to the enhanced stability of the cell membrane, the hydrogen yield of the efeB/OE-CdS system increased by 1.3 times compared to the control, accompanied by a 49.1% reduction in malondialdehyde (MDA) content. This study proposes an effective strategy to alleviate the toxicity of mixed biological nanoparticle systems and efficiently harness optoelectronic electrons, thereby achieving higher hydrogen production in bioremediation.

Transdural circumferential decompression for thoracic spinal stenosis caused by beak-type ossification of the posterior longitudinal ligament: a technical note.

PURPOSE: Thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine is usually progressive and responds poorly to conservative therapy, making surgery the only effective treatment option. A variety of surgical procedures have been developed to treat thoracic OPLL. However, the optimal surgical approach for removal of thoracic OPLL remains unclear. In the present study, we described a newly modified posterior approach for the removal of OPLL: circular decompression via dural approach, and complete removal of OPLL can be achieved under direct vision and without neurological deficit. MATERIALS AND METHODS: Three patients with beak-type thoracic OPLL presented with progressive thoracic myelopathy and leg weakness. Magnetic resonance imaging showed the spinal cord severely compressed. The surgical management of the three patients involved the 'cave-in' circular decompression and transdural resection of OPLL. RESULTS: Transdural circumferential decompression was successfully performed in all three patients. Clinical outcome measures, including pre- and postoperative radiographic parameters, were assessed. All of the patients were followed up for an average of 12 months (ranging from 10 to 15 months), and no surgery-related complications occurred. Weakness relief and neural function recovery were satisfactorily achieved in all patients by the final follow-up. CONCLUSIONS: Transdural circumferential decompression was an effective method for thoracic spinal stenosis caused by concurrent beak-type OPLL, by which OPLL could be safely removed. It is especially useful when there is a severe adhesion between the dura OPLL.

Photocatalytic performance of an α-Fe2O3 electrode and its effects on the growth and metabolism of Citrobacter freundii.

Electronic exchanges occur between semiconductor minerals and microorganisms. However, researchers have focused on the photocatalytic degradation of pollutants by semiconductor minerals, and there is a limited amount of studies on semiconductor photogenerated electrons that influence the growth and energetic mechanisms of bacteria. Bioelectrochemical systems (BES) are important new bioengineering technologies for investigating the mechanisms by which bacteria absorb electrons. In this work, we built a BES that used α-Fe2O3 nanorods as a photoanode and Citrobacter freundii as bio-cathode bacteria to explore the effect of photoelectrons on C. freundii growth and metabolism. The photoanode was prepared by a hydrothermal synthesis method. As confirmed by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), the photoanode was made of α-Fe2O3. Corresponding scanning electron microscope (SEM) images showed that α-Fe2O3 nanorod arrays formed with a diameter of 50 nm, and the band gap was 2.03 eV, as indicated by UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The C. freundii growth metabolism changed significantly because of photoelectrons; under light conditions, the growth rate of C. freundii significantly accelerated, and as inferred from the three-dimensional fluorescence spectrum, the protein, humic acid, and NADH concentrations were significantly higher at 72 h. According to the changes in the organic acid content, photoelectrons participated in the reductive tricarboxylic acid cycle (rTCA) to enhance growth and metabolism. The results of the study have broad implications for advancing fields that study the effects of semiconductor minerals on electroactive microorganisms and the semiconductor-photoelectronic transport mechanisms of electroautotrophic microorganisms. KEY POINTS: • For the first time, A BES was built that used α-Fe2O3 nanorods as a photoanode and C. freundii as a bio-cathode bacteria. • Photoelectrons produced by α-Fe2O3 photoelectrode promote the growth of C. freundii. • Effects of photoelectrons on C. freundii metabolism were conjectured by the changes of organic acids and NADH.

Application of open-door laminoplasty with ARCH plate fixation in cervical intraspinal tumors.

BACKGROUND: The open-door laminoplasty is an effective procedure for the treatment of cervical spondylotic myelopathy. However, little information is available about the surgical results of open-door laminoplasty in the treatment of intraspinal tumors. In the present study, we aimed to investigate the clinical effect of open-door laminoplasty with ARCH plate fixation in the treatment of cervical intraspinal tumors. METHODS: This was a retrospective study. From January 2013 to May 2018, 38 patients (13 males and 25 females, the average age of 44 ± 17 years) with cervical intraspinal tumors underwent open-door laminoplasty with ARCH plate fixation in our hospital. The operation time, blood loss, pre- and postoperative visual analog scale (VAS), and Japanese Orthopedic Association (JOA) scores were determined. To determine the radiographic outcomes, cervical X-ray film and magnetic resonance imaging (MRI) were performed before and after the operation, and cervical X-ray sagittal film was used to measure Cobb angle. The clinical data before and after the operation were compared by t-test. RESULTS: A total of 38 patients underwent a successful operation and demonstrated primary healing. The average operation time was 113 ± 12 min. The average blood loss was 120 ± 19 mL. All patients were followed up for 26.1 ± 2.8 months, and the final follow-up time was more than 24 months. VAS scores were much better at 24 months after operation compared with those before the operation, which were decreased from 6.1 ± 1.1 to 1.4 ± 0.7 (t = 32.63, P < 0.01). The JOA score was improved from 9.9 ± 1.5 to 15.5 ± 0.6 (t = - 18.36, P < 0.01), and the mean JOA recovery rate was 79% ± 11% at 24 months after the operation. There was no significant difference in Cobb angle between pre-operation and 24 months after the operation, which was 9.8 ± 2.6 and 10.3 ± 3.1 respectively (t = - 0.61, P > 0.05). Neither spinal malalignment on the coronal plane nor displacement of the laminoplasty flap was observed on postoperative cervical X-ray and MRI examinations at the final follow-up. CONCLUSIONS: Open-door laminoplasty with ARCH plate fixation was a safe and effective surgical approach for the treatment of cervical intraspinal tumors.

The prediction of two-dimensional PbN: opened bandgap in heterostructure with CdO.

The development of two-dimensional (2D) materials has received wide attention as a generation of optoelectronics, thermoelectric, and other applications. In this study, a novel 2D material, PbN, is proposed as an elemental method using the prototype of a recent reported nitride (J. Phys. Chem. C 2023, 127, 43, 21,006-21014). Based on first-principle calculations, the PbN monolayer is investigated as stable at 900 K, and the isotropic mechanical behavior is addressed by the Young's modulus and Poisson's ratio at 67.4 N m-1 and 0.15, respectively. The PbN monolayer also presents excellent catalytic performance with Gibbs free energy of 0.41 eV. Zero bandgap is found for the PbN monolayer, and it can be opened at about 0.128 eV by forming a heterostructure with CdO. Furthermore, the PbN/CdO is constructed by Van der Waals interaction, while the apparent potential drop and charge transfer are investigated at the interface. The PbN/CdO heterostructure also possesses excellent light absorption properties. The results provide theoretical guidance for the design of layered functional materials.

Patient delay of patients with pulmonary tuberculosis in Yantai, China, 2013 to 2022: Analysis of a case series.

Patient delay increases the morbidity and mortality due to tuberculosis (TB). This study aimed to assess patient delay among patients with pulmonary tuberculosis in Yantai from 2013 to 2022, and to analyze factors related to patient delay. Data of patients with pulmonary tuberculosis in Yantai City from 2013 to 2022 were obtained from the Tuberculosis Management Information System of the Chinese Disease Prevention and Control System. Statistical analyses were performed using the SPSS.26.0 software. The trend in patient delay rate was tested using the chi-square trend test. Univariate analyses were performed using the chi-square test, and factors with statistically significant differences in the univariate analysis were included in the binary logistic regression analysis to identify the factors affecting patient delay. Patient delay was defined as an interval of more than 14 days between the onset of clinical symptoms and the patient first visit to a healthcare facility. From 2013 to 2022, the median delay time for patients with pulmonary tuberculosis in Yantai was 28 ±â€…52 days and the patient delay rate was 69.5%. There was an overall increasing trend in the rate of patient delay as the number of years increased. Univariate analyses revealed statistically significant differences in patient delay in terms of age, occupation, patient source, domicile, pathogenetic results, and the presence of comorbidities (all P < .05). The results of logistic regression analysis showed that the age was 20 to 39, 40 to 59, and ≥ 60 years (OR = 1.365, 95%CI: 1.156-1.612; OR = 1.978, 95%CI: 1.660-2.356; OR = 1.767, 95%CI: 1.480-2.110), occupation was domestic and un-employed (OR = 1.188, 95%CI: 1.071-1.317), domicile as mobile population (OR = 1.212, 95%CI: 1.099-1.337), and positive pathogenic results (OR = 1.242, 95%CI: 1.015-1.520) were risk factors for patient delay. Patient delays were serious among pulmonary tuberculosis patients in Yantai City, 2013 to 2022, and patient delay was related to factors such as age, occupation, domicile, patient source, and pathogenetic results.

3D printed polycaprolactone/ß-tricalcium phosphate/carbon nanotube composite - Physical properties and biocompatibility.

Three-dimensional (3D) printing is a bio-fabrication technique used to process tissue-engineered scaffolds for bone repair and remodeling. Polycaprolactone (PCL)/ß-tricalcium phosphate (TCP) has been used as a base and osteoconductive biomaterial for bone tissue engineering in the past decades. The current study reveals the fabrication of a polycaprolactone (PCL)/ß-tricalcium phosphate (TCP) scaffold by incorporating carbon nanotubes (CNT) via 3D printing. The physical properties and cytocompatibility of a new type of tissue engineering composite from polycaprolactone/ß-tri-calcium phosphate/carbon nanotubes were investigated, and it was an absorbable scaffold prepared via furnace deposition 3D printing technology. The scaffold was designed with CAD software, and the composite material was fabricated via 3D printing. The printed composite material was tested for mechanical strength, scanning electron microscope (SEM) analysis, porosity calculation, systemic toxicity test, hemolysis rate determination, and effect on the proliferation of rat adipose-derived stem cells cultured in vitro. A composite scaffold with a length of 15 mm, width of 10 mm, and height of 5 mm was manufactured through CAD software drawing and 3D printing technology. Scanning electron microscopy measurements and analysis of the internal pore size of the stent are appropriate; the pores are interconnected, and the mechanical strength matches the strength of human cancellous bone. The calculated porosity of the stent was >60%, non-toxic, and non-hemolytic. The proliferation activity of the ADSC co-cultured with different scaffold materials was as follows: polycaprolactone/ß-tricalcium phosphate/0.2% carbon nanotube scaffolds > polycaprolactone/ß-tricalcium phosphate/0.1% carbon nanotube scaffolds > polycaprolactone/ß-tricalcium phosphate/0.3% carbon nanotube scaffolds > polycaprolactone/ß-tricalcium phosphate scaffolds (P < 0.05). The results showed that polycaprolactone/ß-tricalcium phosphate/0.2% carbon nanotube scaffolds promoted the adhesion and proliferation of ADSC. The combination of 3D printing technology and CAD software can be used to print personalized composite stents, which have the characteristics of repeatability, high precision, and low cost. Through 3D printing technology, combining a variety of materials with each other can provide the greatest advantages of materials. The waste of resources was avoided. The prepared polycaprolactone/ß-tri-calcium phosphate/0.2% carbon nanotube scaffold has a good pore structure and mechanical properties that mimic human cancellous bone, is non-toxic and non-hemolytic, and is effective in promoting ADSC proliferation in vitro. Given this correspondence, 3D printed scaffold shows good biocompatibility and strength, and the fabrication method provides a proof of concept for developing scaffolds for bone tissue engineering applications.

Topical hemostatic agents in spinal surgery.

Spinal surgery can be associated with significant intraoperative blood loss which may lead to various complications. As the number of patients undergoing spinal surgery increases over time, accurate and effective hemostasis becomes critically important. Despite various surgical hemostatic techniques, conventional interventions such as compression, suture, ligation, and heat-generating cautery, are not suitable for osseous and epidural venous plexus bleeding during spinal procedures. Therefore, a variety of hemostatic agents have been developed to promote hemostasis. As they differ in terms of mechanism, form, application and potential adverse reactions, it is important to understand the natural features of existing agents. Here we comprehensively review currently available topical hemostatic agents from different sources and summarize their mechanisms of action, applications, and current or potential utilization in spinal surgery. We found hemostatic agents from different sources exert hemostatic actions through different mechanisms. In addition, topical hemostatic agents play various roles in spinal surgery including as hemostatic agent, dura mater repair, drug-carrier, skin closure, and fibrosis prevention. Compressive neurological complications are the most common complications of these hemostatic agents. Therefore, optimal use in spinal environments should match their features, indications, and efficacy with clinical conditions.

Fe3 O4 nanozyme coating enhances light-driven biohydrogen production in self-photosensitized Shewanella oneidensis-CdS hybrid systems.

Solar-driven biohybrid systems that produce chemical energy are a valuable objective in ongoing research. However, reactive oxygen species (ROS) that accompany nanoparticle production under light radiation severely affect the efficiency of biohybrid systems. In this study, we successfully constructed a two-hybrid system, Shewanella oneidensis-CdS and S. oneidensis-CdS@Fe3 O4 , in a simple, economical, and gentle manner. With the Fe3 O4 coating, ROS were considerably eliminated; the hydroxyl radical, superoxide radical, and hydrogen peroxide contents were reduced by 66.7%, 65.4%, and 72%, respectively, during light-driven S. oneidensis-CdS hydrogen production. S. oneidensis-CdS@Fe3 O4 showed a 2.6-fold higher hydrogen production (70 h) than S. oneidensis-CdS. Moreover, the S. oneidensis-CdS system produced an additional 367.8 µmol g-dcw-1 (70 h) of hydrogen compared with S. oneidensis during irradiation. The apparent quantum efficiencies of S. oneidensis-CdS and S. oneidensis-CdS@Fe3 O4 were 6.2% and 11.5%, respectively, exceeding values previously reported. In conclusion, a stable nanozyme coating effectively inhibited the cytotoxicity of CdS nanoparticles, providing an excellent production environment for bacteria. This study provides a rational strategy for protecting biohybrid systems from ROS toxicity and contributes to more efficient solar energy conversion in the future.

A Review and Summary of Patients with Symptomatic Postoperative Discal Pseudocysts of the Lumbar Spine.

OBJECTIVE: Postoperative discal pseudocyst (PDP) is a rare complication after discectomy. This study aimed to summarize the characteristics, pathological mechanisms and management of PDPs. METHODS: Nine patients with PDP who received surgical treatment at our institution from January 2014 to December 2021 were retrospectively reviewed. A systematic review of the literature on PDP was performed. The demographic data, clinical and imaging features, surgical options and patient prognosis were analyzed. RESULTS: Among the nine patients treated at our center, seven were male and two were female. The mean patient age (± standard deviation) at the time of surgery was 28.3 ± 5.7 years (range 18-37 years). The first operation performed on seven patients was percutaneous endoscopic transforaminal discectomy (PETD) and two patients underwent microdiscectomy. The time to conservative treatment before surgical intervention was 20 ± 9.2 days. In three cases, the disc cysts were located in L4/5 and in six cases the lesions were located in L5/S1. Intervertebral disc cyst interventions included foraminal scope (three cases), open discectomy (three cases), conservative treatment with a quadrant channel (one case) and CT-guided puncture (one case). All patients fully recovered after surgery and the mean follow-up time was 3.5 ± 2.1 years. A literature review identified 14 relevant articles that reported 43 PDP cases of PDP. CONCLUSION: PDP occurs in Asian males with mild intervertebral disc degeneration and occurs 1 month after discectomy. Treatment should be based on specific patient scenarios. Conservative treatment is necessary and surgery should be performed with caution.

A Novel Grain-Based DEM Model for Evaluating Surface Integrity in Scratching of RB-SiC Ceramics.

A novel grain-based DEM (Discrete Element Method) model is developed and calibrated to simulate RB-SiC (Reaction-Bonded Silicon Carbide) ceramic and associated scratching process by considering the bonded SiC and Si grains and cementitious materials. It is shown that the grain-based DEM model can accurately identify transgranular and intergranular cracks, and ductile and brittle material removal modes. It also shows that by increasing the scratching speed or decreasing the depth of cut, the maximum depth of subsurface damage decreases, because the scratching force is relatively large under the low scratching speed or large depth of cut that facilitates the occurrence of transgranular cracks, large grain spalling from the target surface and the propagation of median cracks into the target subsurface. It has further been found that increasing the cutting-edge radius can enhance the target ductile machinability and reduce the target subsurface damage.

New solution to build constructed wetland in cold climatic region.

Constructed wetland is an efficient and convenient wastewater treatment technology that has been widely used in China and elsewhere. However, seasonal frozen soil is easily formed in the cold regions of northern China. The local wetlands are in the frozen soil layer, causing the pollutants from wastewater not to be removed well. Therefore, a new constructed wetland structure that uses shallow geothermal energy to keep the wetland not frozen in the winter is proposed in this paper. The results of the experiment show that the average removal rates of total nitrogen, ammonium ion, and total phosphorus in the multistage constructed wetland system are 54.8%, 44.5%, and 77.7%, respectively. This performance is substantially better than that of conventional wetlands in winter. The proposed wetland structure can be applied to conventional wetlands and avoid the conventional wetlands being idle during cold seasons, which is conducive to the popularization of constructed wetlands (CWs) in cold regions.

Application of Laminoplasty Combined with ARCH Plate in the Treatment of Lumbar Intraspinal Tumors.

OBJECTIVE: To investigate the bone fusion and clinical effect of laminoplasty combined with ARCH plate fixation in the treatment of lumbar intraspinal tumors. METHODS: This was a clinical study. From June 2017 to January 2019, 24 patients (seven males and 17 females, average age 40 ± 16 years) with lumbar intraspinal tumors underwent laminoplasty combined with ARCH plate fixation in our hospital. The bone fusion was evaluated by X-ray and computed tomography (CT) scans that were taken 15.2 ± 2.17 months postoperatively. Each segment showed a bone bridge on one side, which was classified as "segmental partial fusion." Each segment showed bilateral bone bridges, which were classified as "segmental complete fusion". When all segments of the patient showed bilateral bone bridging so that the replanted lamina and the host lamina became a unit on the CT scan, it was defined as "complete fusion". In addition, the operation time and blood loss were recorded. Fisher's exact test was used to analyze the potential influencing factors of bone healing, including age (≤40 years vs >40 years), gender, number of operated levels (single vs two). Paired t-test was used to analyze pre- and postoperative Oswestry Disability Index (ODI) scale and low back and leg pain visual analog scale (VAS). RESULTS: A total of 33 segments of laminoplasty were successfully performed in 24 patients. The average operation time was 128 ± 18 minutes. The average blood loss was 110 ± 19 mL. All patients were followed up at least 12 months after operation (average, 15.2 ± 2.17 months). At the final follow-up, according to the definition of this study, the proportion of "segmental partial fusion" and "segmental complete fusion" were 30.3% (10/33) and 69.7% (23/33), respectively. And the proportion of patients with "complete fusion" was 70.8% (17/24). Age, gender, and number of operated levels were not associated with the fusion (P = 1.0, 0.37, and 0.06, respectively). ODI and VAS were much better at 1 month after operation and the final follow-up than those before the operation (P < 0.01). At 6 months after operation, the results of magnetic resonance imaging (MRI) showed that the supraspinous ligament was repaired, and there were no complications, such as spinal epidural scar recompression. CONCLUSIONS: Laminoplasty combined with ARCH plate was a better surgical method, and 70.8% of the patients showed complete bone fusion and there was no case of bilateral nonunion.

[Epidemiological study on risk factors of hepatitis E in Yantai, Shandong province].

OBJECTIVE: To study the prevalent characteristics and risk factors of viral hepatitis E in Yantai and the relative for strategy on viral hepatitis E control in the area. METHODS: Data on viral hepatitis E incidence reported by the Notifiable Infectious Disease Reporting System in 2005-2009 was analyzed. 2028 persons were chosen for hepatitis E virus (HEV) antibody detection by enzyme linked immunosorbent assay method. RT-nPCR method was applied to obtain the sequence of HEV in HEV cases. A case-control study was used to identify the risk factors of HEV infection. RESULTS: The distribution of HEV cases was sporadic in Yantai, and the annual incidence rate was 5.70/100 000, with spring as the prevalent season. Farmers were the main population involved and with those over the age of 40. Regional distribution was mainly along the coastline. Data from the sequential analysis showed that gene type of local patients was type 4 and healthy person whose HEV-IgM was positive was type l. Finding from the case-control study suggested that eating seafoods, living condition in the households and unhealthy habits played important roles in the infection of HEV. Results from multiple logistic regression showed that eating seafood, with eat-out history, drinking alcohol and un-boiled water were the main risk factors in the infection of HEV. CONCLUSION: The level of HE in Yantai will maintain in a high level, but there is no chance of epidemic outbreak of HE in large range. Population of incidence mainly concentrates on farmers.