[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.

Role of HA and BG in engineering poly(ε-caprolactone) porous scaffolds for accelerating cranial bone regeneration

Effects of varied bioactive fillers on the biological behavior of porous polymer/inorganic composite scaffolds are lack of comprehensive comparison and remain elusive. Moreover, composite scaffolds with high porosity suffer from inferior mechanical performance. Herein, high-pressure molding and salt leaching were employed to prepare poly(ε-caprolactone) (PCL) composite porous scaffolds loaded with hydroxyapatite (HA) and bioactive glass (BG), respectively. Structural analysis indicated all the porous scaffolds presented interconnected open-pore structure with the porosity of ~87% and pore size of ~180 μm, hinging on the amounts and size of porogen. Compared to PCL/HA scaffolds, PCL/BG scaffolds showed ~2.3-fold augment in the water absorption. Attributing to the compact framework, the PCL/HA and PCL/BG porous scaffolds exhibited outstanding compressive modulus, which was notably higher than other PCL composite porous scaffolds reported in literatures. Cells culture results demonstrated that PCL/BG scaffolds displayed higher expression of osteogenic differentiation than PCL and PCL/HA scaffolds. Furthermore, in vivo results showed that more mature bone was formed within PCL/BG scaffolds than PCL/HA scaffolds, manifesting that the introduction of BG accelerated cranial bone regeneration to obtain complete bone healing within a short time. Therefore, these data indicate that PCL/BG scaffolds are more competitive for bone tissue engineering application. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 654-662, 2019.

Wearable Polyethylene/Polyamide Composite Fabric for Passive Human Body Cooling

Personal cooling technologies (PCTs) locally control the temperature of an individual instead of a whole building and are thus energy saving. However, most PCTs still consume energy and are heavy in weight, restricting their application among human beings. To achieve personal thermal comfort and no energy consumption on hot summer days, we designed a bilayer structure fabric with high thermal comfort by increasing the dissipation of human thermal radiation and reducing solar energy absorption simultaneously. The fabric consisted of two layers, including a polyethylene film with nanopores (100-1000 nm in pore size) and a film made of nylon 6 nanofibers (ca. 100 nm in diameter) with beads (ca. 230 nm in diameter), which could increase the visible light reflectance but not affect the infrared wave radiation. Therefore, the designed fabric showed a high heat dissipation power, which was 14.13, 17.93, and 17.93 W/m² higher than that of the selected traditional textiles of cotton, linen, and odile, respectively, suggesting good cooling capability. Its cooling performance was better than those reported by the previous research works even at a higher ambient temperature. Meanwhile, the moisture penetrability and hygroscopic property results indicated that the wearing comfort of the designed fabric reached the levels of the selected traditional textiles.

Erratum: Observation of D^{0} Meson Nuclear Modifications in Au+Au Collisions at sqrt[s_{NN}]=200 GeV [Phys. Rev. Lett. 113, 142301 (2014)]

This corrects the article DOI: 10.1103/PhysRevLett.113.142301.

Flow-Induced Precursor Formation of Poly(l-lactic acid) under Pressure

For the first time, the influences of two inevitable processing fields (pressure and flow fields) on the crystallization of a semirigid molecular chain polymer, that is, poly(l-lactic acid) (PLLA), were explored using a homemade pressuring and shearing device. The results reveal that the shear rate facilitated the generation of precursor because it induced oriented segment formation. It was found that the most sensitive shear temperature for the generation of PLLA precursor under 100 MPa was 180 °C. When the shear temperature was higher (e.g., 190 °C), the relaxation of shear-induced oriented segments was too quick to induce the generation of PLLA precursor. Oppositely, at a lower shear temperature (170 °C), the oriented segments were hard to relax within the whole shear rate range (3.1-31.4 s^-1). Annealing treatment was infaust to the PLLA precursor formation because it promoted the relaxation of oriented segments. Different from the shear and annealing, pressure played a more complicated role in the formation of PLLA precursor. Pressure decreased the free volume between PLLA molecular chains and meantime increased the supercooling of PLLA melt. In addition, PLLA chains tended to form locally oriented segment bundles to adapt to the pressurized state, which facilitated the formation of PLLA precursor and the following crystallization process. These two factors lowered the movability of PLLA chains and suppressed the relaxation of chain, so shear-induced orientation facilitated PLLA precursor formation under pressure. In that case, pressure and shear flow showed a synergetic promoting effect on the generation of PLLA precursor and the following crystallization process. These meaningful results could be helpful for comprehending the relationship between crystallization conditions and the crystallization behavior of PLLA and thus would provide guidance to fabricating the final products through controlling the crystallization process of PLLA.

Ultralight Cellulose Porous Composites with Manipulated Porous Structure and Carbon Nanotube Distribution for Promising Electromagnetic Interference Shielding

Lightweight conductive polymer composites based on biomass could be a promising candidate for electromagnetic interference (EMI) shielding application. Herein, tailoring porous microstructure and regulating the distribution of carbon nanotubes (CNTs) in cellulose composites are attempts to achieve highly efficient EMI shielding properties accompanying desired mechanical property and low density. Specifically, aligned porous structure is fabricated by ice-template freeze-drying method; meanwhile, CNT is regulated to decorate inside the cellulose matrix (CNT-matrix/cellulose porous composites) or to directly bind over the cellulose cell walls (CNT-interface/cellulose porous composites). It is found that, owing to the preferential distribution of CNT on the cell walls, the CNT-interface/cellulose porous composites possess a very high electrical conductivity of 38.9 S m^-1 with an extremely low percolation threshold of 0.0083 vol % with regard to CNT-matrix/cellulose porous composites. Therefore, a shielding effectiveness of 40 dB with merely 0.51 vol % CNT under a thickness of 2.5 mm is achieved in CNT-interface/cellulose porous composites, which is attributed to efficient multiple reflections and the accompanying absorption with promoted conductivity and better-defined porous structure. More laudably, the CNT-interface/cellulose porous composites reveal a superior mechanical property with a specific modulus of 279 MPa g^-1 cm³. The value behind the current work is to pave an effective way to fabricate environmentally benign, high-performance EMI shielding materials to practically boost numerous advanced applications of cellulose.