Electrospun PHB/Chitosan Composite Fibrous Membrane and Its Degradation Behaviours in Different pH Conditions

Peripheral nerve injury (PNI) is a neurological disorder that causes more than 9 million patients to suffer from dysfunction of moving and sensing. Using biodegradable polymers to fabricate an artificial nerve conduit that replicates the environment of the extracellular matrix and guides neuron regeneration through the damaged sites has been researched for decades and has led to promising but primarily pre-clinical outcomes. However, few peripheral nerve conduits (PNCs) have been constructed from controllable biodegradable polymeric materials that can maintain their structural integrity or completely degrade during and after nerve regeneration respectively. In this work, a novel PNC candidate material was developed via the electrospinning of polyhydroxy butyrate/chitosan (PHB/CS) composite polymers. An SEM characterisation revealed the resultant PHB/CS nanofibres with 0, 1 and 2 wt/v% CS had less and smaller beads than the nanofibres at 3 wt/v% CS. The water contact angle (WCA) measurement demonstrated that the wettability of PHB/CS electrospun fibres was significantly improved by additional CS. Furthermore, both the thermogravimetric analysis (TGA) and differentiation scanning calorimetry (DSC) results showed that PHB/CS polymers can be blended in a single phase with a trifluoracetic solvent in all compositions. Besides, the reduction in the degradation temperature (from 286.9 to 229.9 °C) and crystallinity (from 81.0% to 52.1%) with increasing contents of CS were further proven. Moreover, we found that the degradability of the PHB/CS nanofibres subjected to different pH values rated in the order of acidic > alkaline > phosphate buffer solution (PBS). Based on these findings, it can be concluded that PHB/CS electrospun fibres with variable blending ratios may be used for designing PNCs with controlled biodegradability

A Simple Model for Elastic-Plastic Contact of Granular Geomaterials

We propose a simple elastic-plastic contact model by considering the interaction of two spheres in the normal direction, for use in discrete element method (DEM) simulations of geomaterials. This model has been developed by using the finite element method (FEM) and nonlinear fitting methods, in the form of power-law relation of the dimensionless normal force and displacement. Only four parameters are needed for each loading-unloading contact process between two spheres, which are relevant to material properties evaluated by FEM simulations. Within the given range of material properties, those four parameters can be quickly accessed by interpolating the data appended or by regression functions supplied. Instead of the Von Mises (V-M) yield criterion, the Drucker-Prager (D-P) criterion is used to describe the yield behavior of contacting spheres in this model. The D-P criterion takes the effects of confining pressure, the intermediate principal stress, and strain rate into consideration; thus, this model can be used for DEM simulation of geomaterials as well as other granular materials with pressure sensitivity

Recognition and Selection of Governance Modes of Private Listed Enterprises Based on BP Neural Network

Exploring the governance modes of private listed enterprises, this paper divides private listed enterprises into categories of small, medium and large. The governance modes of private listed enterprises can be divided into 9 categories according to two different management intensities of equity capital governance and manpower capital governance. The 9 categories of governance modes of private listed enterprises are identified by using the BP neural network mode. This paper analyses the evolution of private listed companies’ governance modes at different scales and analyses various governance modes. Therefore, small, medium and large private listed companies choose the “strong equity and weak manpower”, “moderate equity and moderate manpower” and “weak equity and moderate manpower” governance modes, respectively. This paper comparatively analyses the governance efficiency of governance modes at different scales. The results show that “moderate equity and moderate manpower” is the most effective management mode for all three scales

Contact dermatitis caused by prevention measures during the COVID-19 pandemic: a narrative review

IntroductionDuring the outbreak of Coronavirus disease 2019 (COVID-19), health care workers wore personal protective equipment including masks, gloves and goggles for a long time. In order to reduce the transmission routes of the virus, public places were sprayed with disinfectant. Moreover, the body, hands and clothing were frequently disinfected and washed for hygiene purposes. Studies have shown that these practices could easily irritate the skin and damage the skin barrier. Long-term irritation or exposure to allergens may lead to the occurrence of contact dermatitis (CD).MethodsSubject headings were searched via the National Library of Medicine (PubMed) and web of science databases: COVID-19; contact dermatitis; adverse skin reaction; PPE; dermatitis; mask; glory; hand hygiene, disinfection; face shield; goggle; protect cloth. A total of 246 and 646 articles were retrieved from the two databases, respectively. 402 articles remained after removing duplicates. Reviews, non-English articles, articles that could not be accessed to read or did not conform to our topic were excluded. Finally, a total of 32 cross-sectional studies, 9 case reports and 2 randomized controlled trials were included.DiscussionThis article reviews reports of CD caused by various prevention and hygiene measures during the COVID-19 pandemic. The amount of skin damage caused by COVID-19 prevention measures could be decreased by improved education about skin management

Emerging role of ferroptosis-related circular RNA in tumor metastasis

Tumor metastasis is an important factor that contributes to the poor prognosis of patients with tumors. Therefore, to solve this problem, research on the mechanism of metastasis is essential. Ferroptosis, a new mode of cell death, is characterized by membrane damage due to lipid peroxidation caused by iron overload. Many studies have shown that excessive ferroptosis can affect tumor metastasis and thus inhibit tumor progression. Recently, circular RNA (circRNA), a type of non-coding RNA, has been shown to be associated with the progression of ferroptosis, thus influencing tumor development. However, the specific mechanisms by which circRNAs affect the progression of ferroptosis and their roles in tumor metastasis are not known. In this review, we systematically discuss the role of circRNAs in regulating tumor ferroptosis and their mechanism of action through sponging miRNAS in various tumors, thereby impacting metastasis. This review helps elucidate the relationship and role of ferroptosis-related circRNAs in tumor metastasis and may provide future researchers with new ideas and directions for targeted therapies

Randomized controlled trial on the effects of mindfulness-based respiratory decompression therapy in claustrophobic patients undergoing MRI inspection

BackgroundClaustrophobia is a psychological disease. It is estimated to occur in 2.1–14.3% of all magnetic resonance imaging (MRI) examinations. Mindfulness decompression is an effective means to treat and reduce fear and anxiety. There is a rare report on the application of mindfulness-based stress reduction therapy in the magnetic resonance examinations of patients with claustrophobia to date.PurposeThe purpose of this study is to explore the intervention effect of mindfulness respiratory decompression therapy on the MRI inspection of patients with claustrophobia.MethodsA total of 86 patients with claustrophobia requiring MRI in our hospital from January 2018 to December 2020 were divided into two groups. The control group was given routine psychological nursing, and the observation group was given a mindfulness breathing technique on the basis of the control group. Before and after the intervention, we compared the intervention effect, satisfaction with nurses’ psychological intervention technique, severe autonomic nervous symptoms during the examination, self-rating anxiety scale (SAS) scores, and profile of mood states revised (POMS-R) scores.ResultsThe total effective rate of intervention in the observation group was 90.90%, which was significantly higher (χ2 = 6.857, p = 0.00004) than that in the control group (26.19%). Severe autonomic nervous symptoms in the observation group were significantly lower than those in the control group (p < 0.05). After the intervention, SAS scores and POMS-R scores in the observation group decreased with statistical significance (p < 0.05).ConclusionMindfulness respiratory decompression therapy can effectively help claustrophobic patients complete an MRI examination, which may be worthy of wide promotion and application in the clinic

GLS as a diagnostic biomarker in breast cancer: in-silico, in-situ, and in-vitro insights

BackgroundRecently, a novel programmed cell death mechanism, Cuproptosis, has been discovered and found to play an important role in the development and progression of diverse tumors. In the present study, we comprehensively investigated the core gene of this mechanism, GLS, in breast cancer.Materials and methodsBulk RNA sequencing data were curated from the TCGA repository to investigate the aberrant expression of GLS over diverse cancer types. Then, we examined its efficacy as a diagnostic biomarker in breast cancer by Area Under Curve (AUC) of the Receiver Operative Characteristic (ROC) curve. Furthermore, by applying siRNA technique, we knocked down the GLS expression level in cancerous cell lines, measuring the corresponding effects on cell proliferation and metastasis. Afterward, we explored the potential implications of GLS expression in the tumor immune microenvironment quantitatively by using several R packages and algorithms, including ESTIMATE, CIBERSORT, etc.ResultsPan-cancer analysis suggested that GLS was aberrantly over-expressed in many cancer types, with breast cancer being typical. More in-depth analyses revealed the expression of GLS exerted a high ROC-AUC value in breast cancer diagnosis. Through the knock-down of GLS expression, it was found that GLS expression was strongly relevant to the growth and metastasis of tumor. Furthermore, it was also found to be correlated with the immune tumor microenvironment.ConclusionWe highlighted that GLS expression might be applicable as a diagnostic biomarker in breast cancer and possess significant implications in the growth and metastasis of tumor and the immune tumor microenvironment, sharing new insights into ontological and personalized medicine

Printability and Applicability of 3D Printing System Loaded with Chlorogenic Acid Hydrogel

Three-dimensional food printing (3DFP) is an efficient way of food processing in line with the future lifestyle. As a delivery system, hydrogel has become a research hotspot because of its remarkable characteristics such as directed delivery. The purpose of this study was to explore the effects of 3DFP on the structure, physical properties and functions of hydrogels containing methylcellulose (MC), chlorogenic acid (CA) and hyaluronic acid (HA) for the purpose of revealing the printability and applicability of hydrogels in 3DFP processing. Texture properties, rheological properties, microstructure, embedding rate and digestive properties of the 3D printed products were measured. The results showed that the best CA-loaded hydrogel system for 3DFP processing consisted of MC, HA and CA at a mass ratio of 8:0.5:0.5. Its printed product showed the smallest width deviation (13.40%), the highest hardness, the maximum elasticity, and the minimum adhesiveness, had compact structure and uniform porosity, was not easy to collapse, and had good supportability and the best printing moldability. 3DFP well optimized the physical structure of hydrogel without changing its chemical properties. The embedding rate of CA was 22.09 percentage points higher than that before 3D printing. In simulated gastrointestinal digestion test, the release rate of CA from the printed product was significantly higher than that of the unprinted samples, showing a good sustained release effect, and the in vitro release of CA was fitted to the Ritger-Peppas model. These results showed that the hydrogel system had good printability and applicability, and 3DFP could significantly improve the targeted release of CA loaded in hydrogel