Surface Epitaxial Crystallization-Directed Nanotopography for Accelerating Preosteoblast Proliferation and Osteogenic Differentiation

Surface nanotopography provides a physical stimulus to direct cell fate, especially in the case of osteogenic differentiation. However, fabrication of nanopatterns usually suffers from complex procedures. Herein, a feasible and versatile method was presented to create unique nanosheets on a poly(ε-caprolactone) (PCL) substrate via surface epitaxial crystallization. The thickness, periodic distance, and root-mean-square nanoroughness of surface nanosheets were tunable by simply altering the PCL concentration in the growth solution. Epitaxial nanosheets possessed an identical composition as the substrate, being a prerequisite to revealing the independent effect of biophysical linkage on the osteogenic mechanism of the patterned surface. Preosteoblasts' response to the epitaxial nanosheets was examined in the aspect of preosteoblast proliferation and osteogenic differentiation. The expression of alkaline phosphatase, collagen type I, osteopontin, and osteocalcin as well as mineralization was significantly promoted by the epitaxial nanosheets. Acceleration of osteogenic differentiation was attributed to activating the TAZ/RUNX2 signaling pathway. The findings demonstrate that surface epitaxial crystallization is a feasible approach to design and construct nanotopography for bone tissue engineering.

[KLF3 regulates the movement, migration and invasion of breast cancer cells through STAT3]

Objective: To observe the effect of KLF3 on the expression of STAT3 in breast cancer cells, and to explore the potential mechanism of KLF3 affecting the movement, migration and invasion of breast cancer cells. Methods: Firstly, the expression of STAT3 was detected by Western blot, real-time fluorescent quantitative PCR, luciferase reporter system and chromatin immunoprecipitation in breast cancer cells. Secondly, the STAT3 promoter mutant was constructed. The plasmid further confirmed the effect of KLF3 on the activity of STAT3 promoter; the cell scratching test and Transwell method were used to detect the ability of cell movement, migration and invasion. Finally, animal experiments were conducted to verify the effect of knockdown of KLF3 on tumor metastasis in animals. Results: In breast cancer cells, knockdown of KLF3 promoted STAT3 protein expression. The mRNA level of STAT3 was increased by (3.58±0.65) fold after knockdown of KLF3 in MDA-MB-231 cells, while the mRNA level of STAT3 was increased by (2.28±0.19) fold after KLF3 knockdown in MCF-7 cells (P<0.001). KLF3 boundto the promoter region of STAT3. The transcriptional activity of STAT3 increased by (2.47±0.87) fold after knockdown of KLF3 in MDA-MB-231 cells, while the transcriptional activity of STAT3 increased by (2.63±0.65) fold after KLF3 knockdown in MCF-7 cells, P<0.01. KLF3 knockdown inhibitedthe movement,migrate and invade of breast cancer cells. Based on this, silence STAT3 partially reversed the function of KLF3. Knockdown of KLF3 promotedtumor metastasis in mice. Conclusions: KLF3 knockdown can promote the transcriptional activity of STAT3, which promotes the protein expression of the latter. KLF3 can affect the movement, migration and invasion of breast cancer cells through STAT3. KLF3 may be a potential target for the treatment of metastatic breast cancer.

Highly Stretchable and Sensitive Strain Sensor with Porous Segregated Conductive Network

Flexible strain sensors based on elastomeric conductive polymer composites (ECPCs) play an important role in wearable sensing electronics. However, the achievement of good conjunction between broad detection range and high sensitivity is still challenging. Herein, a highly stretchable and sensitive strain sensor was developed with the formation of porous segregated conductive network in the carbon nanotube/thermoplastic polyurethane composite via a facile and nontoxic compression-molding plus salt-leaching method. The strain sensor with porous segregated conductive network exhibited perfect combination of ultrawide sensing range (800% strain), large sensitivity (gauge factor of 356.4), short response time (180 ms) and recovery time (180 ms), as well as superior stability and durability. The integrated porous structure intensifies the deformation of segregated conductive network when tension strain is applied, which benefits enhancement of the sensitivity. Our sensor could monitor not only subtle oscillation and physiological signals but also energetic human motions efficiently, revealing promising potential applications in wearable motion monitoring systems. This work provides a unique and effective strategy for realizing ECPCs based strain sensors with excellent comprehensive sensing performances.

[Interference research of umbilical cord mesenchymal stem cells on the pulmonary fibrosis in silicosis rats]

Objective: To explore the effect of the umbilical cord mesenchymal stem cells(UC-MSCs) on the pulmonary fibrosis in silicosis rats. Methods: SPF male Sprague Dawley rats were randomly divided into control group, silica model group and UC-MSCs treatment group with 12 rats each group. SiO(2) intra-tracheal injection(0.5 ml of 50 mg/ml/rat) were applied to silica model group and UC-MSCs treatment groups. After that UC-MSCs treatment group received 1 ml UC-MSCs suspension (3×10(6) cells/ml) by tail vein injection on the 29th, 36th, 43th and 50th day after exposure to the first silica suspension. On the 60th and 75th day after exposure to silica suspension, all animals were examed for pulmonary CT. Then the rats were euthanized on 75th day after the first exposure to silica.Lung's histopathological examination of the rats from all the groups were carried out. The content of hydroxyproline in lungs, TGF-β1 and IL-6 in serum were examined. Results: The lung's histopathological examination showed no obvious inflammatory cell and no fibrosis in the lung tissue of the control group, there were a lot of inflammatory cell aggregation and collagen fiber deposition in silica model group, while in the UC-MSCs intervention group and treatment group, there were less inflammatory cells and collagen fiber. The rats from silica model groups had higher HYP, TGF-β1 and IL-6 than the rats from UC-MSCs treatment group and control group. Lung fields of rats in the control group were clear and no obvious high-density shadow. Different-sized granular high-density shadows or reticular fibrous shadows were found diffusely distributed in the lungs of the rats in silica model group. Lung field of rats in UC-MSCs intervention group and treatment group were less high density shadows, and more clear. Conclusion: UC-MSCs can alleviate the pulmonary fibrosis in silica model rats through regulating the secretion of some fibrosis related cytokines.

[Evaluation of postoperative complications registration status of gastric cancer by medical information: A single center feasibility study]

Objective: To explore the feasibility of assessing complications registration through medical information. Methods: A descriptive case series study was performed to retrospectively collect medical information and complication registration information of gastric cancer patients at Department of Gastrointestinal Cancer Center Ward I, Peking University Cancer Hospital from November 1, 2016 to March 1, 2017 (the first period), and from November 1, 2018 to March 1, 2019 (the second period). Case inclusion criteria: (1) adenocarcinoma confirmed by gastroscopy and biopsy; (2) patients undergoing open surgery or laparoscopic radical gastrectomy; (3) complete postoperative medical information and complication information. Patients who were directly transferred to ICU after surgery and underwent emergency surgery were excluded. Because difference of the complication registration procedure at our department existed before and after 2018, so the above two periods were selected to be used for analysis on enrolled patients. The prescription information during hospitalization, including nursing, medication, laboratory examination, transference, surgical advice, etc. were compared with the current Standard Operating Procedure (SOP, including preoperative routine examinations, inspection, perioperative preventive antibiotic use, postoperative observational tests, inspection, routine nutritional support, prophylactic anticoagulation, and prophylactic inhibition of pancreatic enzymes, etc.) for gastric cancer at our department. Medical order beyond SOP was defined as medical order variation. Postoperative complication was diagnosed using the Clavien-Dindo classification criteria, which was divided into I, II, IIIa, IIIb, IVa, IVb, and V. Medical order variation and complication registration information were compared between the two periods, including consistence between medical order variation and complication registration, missing report, underestimation or overestimation of medical order variation, and registration rate of medical order variation [registration rate = (total number of patients-number of missing report patients)/total number of patients], severe complications (Clavien-Dindo classification ≥ III), medical order variation deviating from SOP and the corresponding inferred grading of complication. The data was organized using Microsoft Office Excel 2010. Results: A total of 177 gastric cancer patients were included in the analysis. The first period group and the second period group comprised 89 and 88 cases, respectively. The registrated complication rate was 23.6% (21/89) and 36.4% (32/88), and the incidence of severe complication was 2.2% (2/89) and 4.5% (4/88) in the first and the second period, respectively. The complication rate inferred from medical order variation was 74.2% (66/89) and 78.4% (69/88), and the incidence of severe complication was 7.9% (7/89) and 4.5% (4/88) in the first and second period, respectively. In the first and second period, the proportions of medical order variation in accordance with registered complication were 36.0% and 45.5% respectively; the proportion of underestimation, overestimation and missing report were 5.6% and 4.5%, 4.5% and 4.5%, 53.9% and 45.5%, respectively; the registration rate of medical order variation was 46.1% and 54.5%; the number of case with grade I complications inferred from medical order variation was 34 (38.2%) and 25 (28.4%), respectively; and the number of grade II was 12 (13.5%) and 15 cases (17.0%), respectively. The reason of the missing report of medical order variation corresponding to grade I complication was mainly the single use of analgesic drugs outside SOP, accounting for 76.5% (26/34) and 64.0% (16/25) in the first and second period respectively, and that corresponding to grade II complication was mainly the use of non-prophylactic antibiotics, accounting for 9/12 cases and 5/15 cases, respectively. Conclusions: Medical information can evaluate the morbidity of complication feasibly and effectively. Attention should be paid to routine registration to avoid specific missing report.

Highly Sensitive and Stretchable Polyurethane Fiber Strain Sensors with Embedded Silver Nanowires

Flexible strain sensors have attracted a great amount of attention for promising applications in next-generation artificially intelligent devices. However, it is difficult for conventional planar strain sensors to meet the requirements of miniature size and light weight for flexible electronics. Herein, a highly sensitive and stretchable fiber strain sensor with a millimeter diameter was innovatively fabricated by the capillary tube method to integrate silver nanowires (AgNWs) in polyurethane (PU) fibers. Scanning electron microscopy results demonstrate that AgNWs were embedded into the surface layer of PU fibers and formed completely conductive networks. The unique AgNW networks endow the PU/AgNW fibers with superior electrical conductivity of 3.1 S/cm, high elongation at break of 265%, wide response range of 43%, high gauge factor of 87.6 up to 22% strain, fast response time of 49 ms, and excellent reliability and stability. Such satisfactory stretchability and sensitivity is attributed to the combination of the highly stretchable PU matrix and the embedded architecture of the AgNW conductive network. Moreover, PU/AgNW fibers can be employed as wearable devices to detect various human motions and to drive light-emitting diodes at a lower voltage (2.7 V).

Interconnected Microdomain Structure of a Cross-Linked Cellulose Nanocomposite Revealed by Micro-Raman Imaging and Its Influence on Water Permeability of a Film

Substantial adsorption of water vapor triggered by hydrogen-bonding interactions between water molecules and cellulose chains (or nanoplates) is hard to avoid in nanocomposite films, although the addition of nanoplates can improve the oxygen (or carbon dioxide) barrier property. In the present work, an effective strategy is raised to decline adsorption by weakening hydrogen-bonding interactions via chemical cross-linking by epichlorohydrin (ECH) without sacrificing the homogeneous dispersion of nanoplates. The generated microdomain structure of the chemical cross-linking reaction via ECH is explicitly revealed by micro-Raman imaging. Unambiguously, Raman maps of scanning elucidate the distribution and morphology of physical and chemical cross-linking domains quantitatively. The chemical cross-linking domains are nearly uniformly located in the matrix at a low degree of cross-linking, while the interconnected and assembled networks are formed at a high degree of cross-linking. ECH boosts the formation of chemical cross-linking microdomains, bringing out the terrific water vapor barrier property and alleviating the interfacial interactions in penetration, consequently magnifying the water contact angle and holding back the water vapor permeability. Our methodology confers an effective and convenient strategy to obtain remarkable water vapor-resistant cellulose-based films that meet the practical application in the packaging fields.

Polydopamine-Assisted Anchor of Chitosan onto Porous Composite Scaffolds for Accelerating Bone Regeneration

Surface function has an importance for the bioactivity of porous polymeric scaffolds. The goal of the present study is to immobilize highly bioactive chitosan (CS) onto the surface of porous composite scaffolds to accelerate bone regeneration. Porous poly(ε-caprolactone) (PCL)/bioactive glass (BG) composite scaffolds with strong anchor of CS were fabricated via mussel-inspired polydopamine (PDA) coating as a bridging layer. In vitro cell culture showed that firm immobilization of CS onto the composite scaffolds significantly enhanced protein adsorption, cell adhesion, and osteogenic differentiation compared to CS-decorated scaffolds via physical adsorption. In vivo assessments demonstrated that covalent immobilization of CS onto the surface of scaffolds obviously promoted cranial bone regeneration in comparison with the counterparts with physical adsorption of CS. The proposed method offers a feasible and effective means to fabricate artificial bioactive scaffolds for bone tissue engineering application.

Baroplastics with Robust Mechanical Properties and Reserved Processability through Hydrogen-Bonded Interactions

Conventional polymers are usually processed at a much higher temperature than room temperature, which inevitably leads to huge energy consumption and degradation of the polymers and thus a low recycling ability. Herein, we synthesized a poly( n-butyl acrylate)@polystyrene (PBA@PS) core-shell polymer to prepare a typical baroplastic (processible at room temperature). However, this type of baroplastics always has a low mechanical property. To solve this problem, in this work, we introduced hydrogen bonds into the matrix and successfully reinforced baroplastics for the first time. The hydrogen-bonded interaction was introduced by complexing PBA@PS with poly(acrylic acid) and poly(ethylene oxide). The results show that the reinforced baroplastics possessed notably enhanced mechanical properties and good processability. Their mechanical strength and modulus reached as high as 5.6 (by 73%) and 10 MPa (by 400%), respectively. Moreover, the baroplastics could be remolded many times at room temperature and, at the same time, still showed a higher tensile strength (10.5 MPa, 3.3 times that of the initial PBA@PS, which was never achieved in previous works), which resulted from the reversible hydrogen bonds and reserved orientation of molecular chains. Our work opened a new path to reinforce baroplastics and could widen their applications. Furthermore, not limited to the hydrogen bonds, more sacrificial bonds, such as ionic bonds, host-guest interactions, and metal-ligand coordination bonds, could be used to fabricate high-performance baroplastics.

[Incidence and mortality of laryngeal cancer in China, 2014]

Objective: To estimate the incidence and mortality of laryngeal cancer in China based on the cancer registration data in 2014, collected by the National Central Cancer Registry (NCCR), and to provide support data for the control and prevention of laryngeal cancer. Methods: The incident and death data of laryngeal cancer in 2014 from 339 cancer registries met the quality criteria of NCCR, and then adopted for analysis. The incident and death number, crude rate, age standardized rate, truncated rate and proportion which stratified by areas (urban/rural) and age were calculated. The nationwide incidence and mortality of laryngeal cancer in 2014 were estimated by combining with those data on national population in 2014. Chinese population census in 2000 and Segi's population were used for age-standardized incidence/mortality rates. Results: It was estimates that 23.4 thousand new cases of laryngeal cancer occurred in China in 2014. There were 20.8 thousand males and 2.6 thousand females. And 14.5 thousand occurred in urban areas, while 8.9 thousand in rural areas. The age standardized rates of incidence by world standard population (ASRs world) in male, female and both genders were 2.05/100, 000, 0.24/100, 000 and 1.14/100, 000, respectively, whereas those were 1.22/100, 000 and 1.03/100, 000 for urban and rural areas. The incidence was much higher in males than females, and slightly higher in urban areas than those in rural areas. Moreover, it was estimates that 13.2 thousand death cases of laryngeal cancer occurred in China in 2014. There were 11.5 thousand males and 1.7 thousand females. And 7.8 thousand occurred in urban areas, while 5.4 thousand in rural areas. The age standardized rates of mortality by ASRs world in male, female and both genders were 1.08/100, 000, 0.14/100, 000 and 0.60/100, 000, respectively, whereas those were 0.60/100, 000 and 0.59/100, 000 for urban and rural areas. The mortality was much higher in males than females, and slightly higher in urban areas than those in rural areas. In males, the age specific incidence and mortality of laryngeal cancer increased greatly from 40-44 and 45-44 years old, respectively, and peaked at age group of 75-79 and >85 years old. In females, the age specific incidence and mortality increased slowly from 50-54 and 60-64 years old, respectively, and peaked at age group of 80-84 and >85 years old. The trends remained similar in urban and rural areas, except for the different peak ages. Conclusions: The incidence and mortality of laryngeal cancer in China are at middle-low levels worldwide, and there are obvious differences between urban and rural areas with distinct gender disparity. Comprehensive prevention and control strategies should be carried out according to local status and age groups.

Hydrophobic Graphene Oxide as a Promising Barrier of Water Vapor for Regenerated Cellulose Nanocomposite Films

Regenerated cellulose (RC) films exhibit poor water barrier performance, which seriously restricts its applications. To address this issue, an impermeable and hydrophobic graphene oxide modified by chemically grafting octadecylamine (GO-ODA) was utilized to enhance the water vapor barrier performance of RC nanocomposite films. Compared to the neat RC film, more than 20% decrease in the coefficient of water vapor permeability (P _H2O) was achieved by loading only 2.0 wt % GO-ODA. The promising hydrophobicity of GO-ODA effectively retarded the formation of hydrogen bonding at the relatively weakened interface between GO and RC, compensating for the diffusion of water vapor molecules at the interface; on the other hand, the fully exfoliated GO-ODA nanosheets were inclined to align with the surface of the as-prepared RC nanocomposite films during hot-pressure drying, creating a much more tortuous pathway for diffusion of water molecules. The new insights could be valuable for widening application of cellulose such as packaging.

Robustly Superhydrophobic Conductive Textile for Efficient Electromagnetic Interference Shielding

Superhydrophobic electromagnetic interference (EMI) shielding textile (EMIST) is of great significance to the safety and long-term service of all-weather outdoor equipment. However, it is still challenging to achieve long-term durability and stability under external mechanical deformations or other harsh service conditions. Herein, by designing and implementing silver nanowire (AgNW) networks and a superhydrophobic coating onto a commercial textile, we demonstrate a highly robust superhydrophobic EMIST. The resultant EMIST shows a synergy of high water contact angle (160.8°), low sliding angle (2.9°), and superior EMI shielding effectiveness (51.5 dB). Remarkably, the EMIST still maintains its superhydrophobic feature and high EMI shielding level (42.6 dB) even after 5000 stretching-releasing cycles. Moreover, the EMIST exhibits strong resistance to ultrasonic treatment up to 60 min, peeling test up to 100 cycles, strong acidic/alkaline solutions, and different organic solvents, indicating its outstanding mechanical robustness and chemical durability. These attractive features of the EMIST are mainly a result of the joint action of AgNWs, carbon nanotubes, polytetrafluoroethylene nanoparticles, and fluoroacrylic polymer. This work offers a promising approach for the design of future durable, superhydrophobic EMISTs, which are capable of remaining fully functional against long-time exposure to extreme conditions, for example, wet and corrosive environments.

[Prospective study on the effect of BMI and waist circumference on diabetes of adults in Zhejiang province]

Objective: To explore the effect of BMI and waist circumference on diabetes of adults. Methods: After excluding participants with heart disease, stroke, cancer and diabetes at baseline study, 53 916 people aged 30-79 in the China Kadoorie Biobank (CKB) study from Tongxiang city of Zhejiang province were recruited. Cox regression model was used to estimate the hazards ratios (HR) for the associations of baseline BMI and waist circumference with incident diabetes. Results: Among 391 512 person-years of the follow-up program between 2004 and 2013 (median 7.26 years), a total of 944 men and 1 643 women were diagnosed as having diabetes. Compared to those with normal weight, after adjusting for known or potential factors, HR of both overweight and obesity in men for incident diabetes appeared as 2.72 (95%CI: 2.47-2.99) and 6.27 (95%CI: 5.33-7.36), respectively. The corresponding figures in women were 2.19 (95%CI: 2.04-2.36) and 3.78 (95%CI: 3.36-4.26). Compared to those with normal waist circumference, after adjusting for known or potential factors, HR of Ⅰgrade andⅡgrade in men for diabetes were 2.56 (95%CI: 2.22-2.95) and 4.66 (95%CI: 4.14-5.24), respectively. The corresponding figures in women were 1.99 (95%CI: 1.80-2.21) and 3.16 (95%CI: 2.90-3.44), respectively. Conclusions: Overweight, obesity and central obesity were all associated with the increased incident of diabetes. Strategies on diabetes prevention should include not only losing weight, but reducing waist circumference as well.

Bone-like Polymeric Composites with a Combination of Bioactive Glass and Hydroxyapatite: Simultaneous Enhancement of Mechanical Performance and Bioactivity

An ideal bone substitute requires not only high bioactivity but also sufficient mechanical performance, which is however inaccessible due to the lack of rational structure and composition design. Here, bioactive glass (BG)/hydroxyapatite (HA)/polyethylene (PE) composites with bone-like structure were prepared via a structuring injection molding. The strong and reciprocating shear field offered by the modified injection molding induced plenty of interlocked shish kebabs, mimicking the aligned collagen fibers in the natural bone. Such a bone-like structure enhanced the strength and toughness of the BG/HA/PE composites simultaneously, compensating the mechanical loss caused by the presence of BG. In vitro cell culture assays demonstrated that the combination of BG and HA significantly promoted cell attachment, proliferation, and alkaline phosphatase activity compared to the use of HA alone. It was attributed to upregulated expression of β-catenin stimulated by BG. The mineralization in simulated body fluid revealed that the BG/HA/PE composite exhibited apatite-forming ability stronger than that of the HA/PE counterpart. The integration of excellent mechanical performance and high bioactivity demonstrated the significant potential of the structured BG/HA/PE composites as load-bearing bone substitutes.