Easy and Green Method to Fabricate Highly Thermally Conductive Poly(decamethylene terephthalamide)/Graphite Nanoplatelets Nanocomposite with Aligned Structure.

With the development of miniaturization and integration of electrical and electronic equipment, the heat accumulation problems caused by the long-term operation of devices have become more and more serious. High thermal-conductivity and high-performance plastic composites have attracted significant interest from both academia and industry. Numerous studies have been recently conducted to enhance the thermal conductivity (TC) of nanofiller-filled polymeric composites. However, the homogeneous dispersion and directional arrangement of nanofillers in the resin matrix are the key factors limiting their effectiveness in enhancing thermal conductivity. Based on the feasibility considerations of mass production and industrial application, this paper reports on a novel preparation method of Poly(decamethylene terephthalamide)/graphite nanoparticle (GNP) nanocomposites with high thermal conductivity. Without borrowing solvents or other reagents, this method can effectively strip the inexpensive scaled graphite into nanoscale for its uniform dispersion and orientation arrangement by relying only on mechanical external forces. The whole technology is simple, green, and easy to industrialize. The fillers were well-dispersed and aligned in the PA10T, which played a role in significantly enhancing the thermal conductivity of the PA10T. In addition, we found that the thermal conductivity of the composites reached 1.20 W/(m·K) at 10 wt% filler content, which was 330% higher than that of the pure matrix. The mechanical properties of the composites were also significantly improved. This work provides guidance for the easy fabrication of thermally conductive composites with aligned structures.

A randomised controlled study on the effects of hernial sac stump fenestration on ultrasound seroma prevention in laparoscopic Type III inguinal hernia repair.

BACKGROUND: The incidence of ultrasound seromas has significantly increased after large hernial sac surgery. Several methods are available for preventing ultrasound seromas, but the clinical results are poor. It has also been demonstrated that hernial sac stump fenestration during laparoscopic incisional hernia repair surgery can significantly decrease the incidence of ultrasound seromas. MATERIALS AND METHODS: Ninety patients aged 18-75 years who were treated in our hospital for primary Type III indirect inguinal hernia from March 2017 to March 2018 were randomised to a preventive fenestration group and a control group. All patients underwent transabdominal preperitoneal repair. The number of ultrasound seromas in the inguinal regions and ultrasound seroma volume on day 6 and months 1 and 3 after surgery in the two groups were compared. The secondary outcomes included length of surgery, urinary retention, acute pain, chronic pain, length of hospitalisation, recurrence rate and other complications. RESULTS: There were no significant differences in demographic characteristics. Ultrasound seroma incidence and ultrasound seroma volume on day 6 and months 1 and 3 after surgery were significantly lower in the preventive fenestration group than that in the control group. There were no significant differences in the length of hospitalisation or incidence of acute pain or urinary retention between the two groups. CONCLUSIONS: Hernial sac stump fenestration after hernial sac transection in inguinal hernia repair surgery is a simple method that can effectively reduce post-operative ultrasound seromas.

Molecular Detection and Quantification of Xanthomonas albilineans in Juice from Symptomless Sugarcane Stalks Using a Real-Time Quantitative PCR Assay.

Leaf scald, a bacterial disease caused by Xanthomonas albilineans (Ashby) Dowson, is a major limiting factor for sugarcane production worldwide. Accurate identification and quantification of X. albilineans is a prerequisite for successful management of this disease. A sensitive and robust quantitative PCR (qPCR) assay was developed in this study for detection and quantification of X. albilineans using TaqMan probe and primers targeting a putative adenosine triphosphate-binding cassette (ABC) transporter gene (abc). The novel qPCR assay was highly specific to the 43 tested X. albilineans strains belonging to different pulsed-field gel electrophoresis groups. The detection thresholds were 100 copies/µl of plasmid DNA, 100 fg/µl of bacterial genomic DNA, and 100 CFU/ml of bacterial suspension prepared from pure culture. This qPCR assay was 100 times more sensitive than a conventional PCR assay. The pathogen was detected by qPCR in 75.1% (410/546) of symptomless stalk samples, whereas only 28.4% (155/546) of samples tested positive by conventional PCR. Based on qPCR data, population densities of X. albilineans in symptomless stalks of the same varieties differed between two sugarcane production areas in China, Beihai (Guangxi Province) and Zhanjiang (Guangdong Province), and no significant correlation between these populations was identified. Furthermore, no relationship was found between these populations of the pathogen in asymptomatic stalks and the resistance level of the sugarcane varieties to leaf scald. The newly developed qPCR assay proved to be highly sensitive and reliable for the detection and quantification of X. albilineans in sugarcane stalks.

Mutual regulation between butyrate and hypoxia-inducible factor-1α in epithelial cell promotes expression of tight junction proteins.

Inflammatory bowel disease is a kind of multi-aetiological chronic disease that is driven by multidimensional factors. Hypoxia-inducible factor-1α (HIF-1α) plays an important role in anti-inflammatory and cellular responses to hypoxia. Previous studies have found that B or T-cell-specific HIF-1α knock out mice exhibit severe colonic inflammation. However, we know very little about other functions of HIF-1α in intestinal epithelial cells (IECs). In our study, HIF-1αΔIEC mice were used to study the function of HIF-1α in IECs. HIF-1α was knocked down in Caco-2 cells by transfection with a small interfering (si) RNA. Immunohistochemical staining and western blotting were used to detect the expression of zonula occluden-1 (ZO-1) and Occludin. The content of colon was harvested for high-performance liquid chromatography analysis to examine the levels of butyrate in the gut. Our research found that HIF-1α played a protective role in dextran sulphate sodium-induced colitis, which was partly due to its regulation of tight junction (TJ) protein expression. Further study revealed that HIF-1α mediated TJ proteins levels by moderating the content of butyrate. Moreover, we found that butyrate regulated TJ protein expression, which is dependent on HIF-1α. These results indicated that there is a mutual regulatory mechanism between butyrate and HIF-1α, which has an important role in the maintenance of barrier function of the gastrointestinal tract.

A randomized study on laparoscopic total extraperitoneal inguinal hernia repair with hernia sac transection vs complete sac reduction.

OBJECTIVE: The management of the hernia sac is the core step of laparoscopic indirect inguinal hernioplasty. In this study, a randomized controlled trial was conducted to evaluate the clinical effect of laparoscopic total extraperitoneal inguinal herniorrhaphy (TEP) with hernia sac transection and complete sac reduction. METHOD: From May 2017 to May 2018, 70 patients aged 18-75 with primary indirect inguinal hernia in our hospital were randomly divided into a transected sac group (TS) and a completely reduced sac group (RS). The primary outcomes compared between the two groups were the hernia sac treatment time, operation time, and the incidence of seroma formation after operation. Secondary outcomes included acute pain, chronic pain (pain which lasted for at least 3 months), hospital stay, recurrence rate, and other complications. RESULT: There were no significant differences in baseline demographic characteristics including age, sex, hernia type, size of hernia defect, and follow-up time between the two groups. The times required for hernia sac separation and operation in the TS group were significantly shorter than in the control group (6.1 ± 2.3 vs. 25 ± 5.8 min for hernia sac separation, p < 0.01; and 35.10 ± 3.50 vs. 54.40 ± 4.20 min for operation, p < 0.01). There was no significant difference in hospitalization time, incidence of acute pain, seroma formation, or urinary retention between the two groups. During the 12-month follow-up period, chronic pain, early recurrence, and other complications were not found in either group. CONCLUSION: Both the hernia sac transection technique and the complete sac reduction technique are safe and reliable. The hernia sac transection technique is a simple and effective hernia sac treatment method. It reduces the operation time and does not increase seroma or acute or chronic pain. It is valuable and likely to be popularly applied.

Aryl hydrocarbon receptor activation alleviates dextran sodium sulfate-induced colitis through enhancing the differentiation of goblet cells.

BACKGROUND: The intestinal inflammation induces disruption of the intestinal barrier function and leads to bacteria invasion. Accumulating evidences revealed that the aryl hydrocarbon receptor (AhR) plays a vital role in maintaining the intestinal barrier function. However, the precise mechanism remains to be unclear. METHODS: Adult C57BL/6J mice were randomly divided into three groups: Sham, DSS and DSS + 6-formylindolo (3, 2-b) carbazole (FICZ)group. The colons and epithelial cell were harvested for histological examination, pro-inflammatory cytokines detection, bacterial load analysis, immunohistochemistry and Muc2 protein analysis. Under physiological condition, AhRKO model and FICZ treatment were used to evaluate the roles of AhR in the differentiation of goblet cells and the expression of Muc2 in mice. In vitro, we used HT29 mol to research the signaling pathway. RESULTS: AhR activation by FICZ could increase the Muc2 expression and the number of goblet cells and reduce bacterial infiltration to ameliorate DSS-induced Colitis. Under physiological conditions, the treatment of FICZ promote the differentiation of goblet cell and the expression of Muc2 and inhibit the notch-signaling. Genetic deletion of AhR led to the loss of goblet cells and the decrease of Muc2 expression and enhance the notch-signaling. In HT29 cells, the differentiation of goblet cell meditated by AhR can be abolished by the inhibitor of AhR, pErk1/2 and knocking-down AhR. CONCLUSION: FICZ promoted the differentiation of goblet cell through AhR-pErk1/2 signaling pathway and ameliorate DSS-induced Colitis.

Using inferior epigastric vascular anatomical landmarks for anterior inguinal hernia repair.

BACKGROUND: Inferior epigastric vascular anatomical landmarks for anterior inguinal hernia repair is an alternative surgical procedure. We present our experience and outcome of the way. METHODS: We performed a retrospective analysis of 230 patients who received anterior tension-free hernia repair between May 2016 to May 2017. Among these cases, 120 were performed using the traditional transinguinal preperitoneal (TTIPP) technique while 100 were performed using the vascular anatomic landmark transinguinal preperitoneal (VALTIPP) technique. Between these two groups, we compared the operation time, length of hospital stay, complication rates, and the visual analog scale (VAS) for pain at 2 days, 3 months, and 6 months after surgery. RESULTS: Surgery was well-tolerated in both groups with no significant hemorrhage or complications. The operation times for the VALTIPP and TTIPP groups were 42.52 ± 9.15 and 53.84 ± 10.64 min (P < 0.05), respectively. Ten patients in the VALTIPP group and 17 patients in the TTIPP group reported sensations of foreign bodies (P < 0.05). The VAS pain score in VALTIPP patients at 2 days (4.0 ± 0.5), 3 months (1.0 ± 0.3), and 6 months (0.9 ± 0.3) were significantly lower when compared with those of TTIPP patients (5.3 ± 0.9 at 2 days, 1.8 ± 0.4 at 3 months, and 1.1 ± 0.1 at 6 months, p < 0.05). No statistically significant differences were found in age, gender, BMI, hernia type and location, follow-up period, incidence of post-operative seromas, recurrence rate, or length of hospital stay. CONCLUSION: Anterior inguinal hernia repair using inferior epigastric vascular anatomical landmarks may lead to reduced operation times, reduced sensations of foreign bodies, and reduced post-operative pain. This technique is simple, practical, and effective in the management of inguinal hernias.

Si@C Microsphere Composite with Multiple Buffer Structures for High-Performance Lithium-Ion Battery Anodes.

In this work, a Si@C microsphere composite with multiple buffer structures is prepared by hydrothermal treatment to solve the fatal drawbacks of serious pulverization and low electronic conductivity of Si anodes. By virtue of ferric citrate being the carefully chosen coating carbon source, the silicon nanoparticles with a SiOx layer are encapsulated by the homogeneous mesoporous carbon layer. The SiOx layer with appropriate toughness can primarily suppress the volume expansion of silicon. The plentiful mesopores in the carbon layer and the framework formed by carbon nanotubes with good mechanical strength can effectively buffer and accommodate the volume change of silicon, and greatly improve the infiltration of the electrolyte to the anode. Meanwhile, the mesoporous carbon and carbon nanotube network also enhance the conductivity of the composite. Therefore, the Si@C electrodes exhibit a high initial charge/discharge capacity of 2956/4197 mAh g-1 at a current density of 0.42 A g-1 , excellent rate capability, and outstanding cycle performance up to 800 cycles by virtue of the multiple buffer structures.

The effect of transabdominal preperitoneal (TAPP) inguinal hernioplasty on chronic pain and quality of life of patients: mesh fixation versus non-fixation.

OBJECTIVES: The aim of this study was to compare the effect of transabdominal preperitoneal (TAPP) inguinal hernioplasty with or without mesh fixation on chronic pain and quality of life of patients. METHODS: One hundred patients with a simple oblique inguinal hernia were included and treated at the Second Affiliated Hospital of Kunming Medical University from July of 2015 to July of 2016. Patients were randomly assigned to TAPP inguinal hernioplasty with mesh fixation (fixation group, n = 50) or without mesh fixation (non-fixation group, n = 50). Observation indices such as mean operative time, time to ambulation, hospitalization expense, and complications were recorded. The visual analog scale (VAS) was adopted for pain evaluation 2 days, 3 months, and 6 months postoperatively. The 36-item short-form health survey (SF-36) was adopted for life quality scoring 3 months postoperatively. RESULTS: No recurrence or incisional infections were observed during follow-up in either group. The mean operative time, time to ambulation, and hospitalization expense of the non-fixation group were all significantly reduced compared to those of the fixation group. The VAS score 2 days, 3 months, and 6 months postoperatively of the non-fixation group were significantly lower than in the fixation group. The physical function, role physical, bodily pain, and general health in the non-fixation group were each significantly higher than in the fixation group. In contrast, vitality, social function, role emotional, and mental health showed no significant differences across groups. CONCLUSIONS: For patients with primary unilateral oblique inguinal hernia with a defect size less than 4.0 cm in diameter, TAPP inguinal hernioplasty without mesh fixation was safe and effective. Furthermore, this shortened the operative time, promoted early ambulation, decreased hospitalization expenses, alleviated postoperative pain, and improved quality of life.

Comparison of multi-modal early oral nutrition for the tolerance of oral nutrition with conventional care after major abdominal surgery: a prospective, randomized, single-blind trial.

BACKGROUND & AIMS: Early oral nutrition (EON) has been shown to improve recovery of gastrointestinal function, length of stay and mortality after abdominal surgery; however, early oral nutrition often fails during the first week after surgery. Here, a multi-modal early oral nutrition program is introduced to promote recovery of gastrointestinal function and tolerance of oral nutrition. METHODS: Consecutive patients scheduled for abdominal surgery were randomized to the multimodal EON group or a group receiving conventional care. The primary endpoint was the time of first defecation. The secondary endpoints were outcomes and the cost-effectiveness ratio in treating infectious complications. The rate of infectious-free patients was regarded as the index of effectiveness. RESULTS: One hundred seven patients were randomly assigned to groups. Baseline characteristics were similar for both groups. In intention-to-treat analysis, the success rate of oral nutrition during the first week after surgery in the multimodal EON group was 44 (83.0%) versus 31 (57.4%) in the conventional care group (P = 0.004). Time to first defecation, time to flatus, recovery time of bowel sounds, and prolonged postoperative ileus were all less in the multimodal EON group (P < 0.05). The median postoperative length of stay in the multimodal EON group was 8 days (6, 12) versus 10 days (7, 18) in the conventional care group (P < 0.001). The total cost of treatment and nutritional support were also less in the multi-modal early oral nutrition group (P < 0.001). The effectiveness was 84.9 and 79.9% in the multimodal EON and conventional care group, respectively (P = 0.475). However, the cost-effectiveness ratio was USD 537.6 (506.1, 589.3) and USD 637.8 (593.9, 710.3), respectively (P < 0.001). CONCLUSION: The multi-modal early oral nutrition program was an effective way to improve tolerance of oral nutrition during the first week after surgery, decrease the length of stay and improve cost-effectiveness after abdominal surgery. TRIAL REGISTRATION: Registration number: ChiCTR-TRC-14004395 . Registered 15 March 2014.

Impact of nutritional support that does and does not meet guideline standards on clinical outcome in surgical patients at nutritional risk: a prospective cohort study.

OBJECTIVE: To investigate the impact of nutritional support on clinical outcomes in patients at nutritional risk who receive nutritional support that meets guideline standards and those who do not. METHODS: This prospective cohort study enrolled hospitalized patients from the Second Affiliated Hospital of Kunming Medical University from February 2010 to June 2012. The research protocols were approved by the university's ethics committee, and the patients signed informed consent forms. The clinical data were collected based on nutritional risk screening, administration of enteral and parenteral nutrition, surgical information, complications, and length of hospital stay. RESULTS: During the study period, 525 patients at nutritional risk were enrolled in the cohorts. Among patients who received nutritional support that met the guideline standards (Cohort 1), the incidence of infectious complications was lower than that in patients who did not meet guideline standards (Cohort 2) (17.1 % vs. 26.9 %, P = 0.01). Subgroup analysis showed that individuals who received a combination of parenteral nutrition (PN) and enteral nutrition (EN) for 7 or more days had a significantly lower incidence of infectious complications (P = 0.001) than those who received only PN for 7 or more days or those who received nutritional support for less than 7 days or at less than 10 kcal/kg/d. Binary logistic regression analysis showed that, after adjusting for confounding factors, nutritional support that met guideline standards for patients with nutritional risk was a protective factor for complications (OR: 0.870, P < 0.002). CONCLUSIONS: In patients at nutritional risk after abdominal surgery, nutritional support that meets recommended nutrient guidelines (especially regimens involving PN + EN ≥ 7 days) might decrease the incidence of infectious complications and is worth recommending; however, well-designed trials are needed to confirm our findings. Nutritional support that does not meet the guideline standards is considered clinically undesirable.

Comprehensive analysis of differential long non-coding RNA and messenger RNA expression in cholelithiasis using high-throughput sequencing and bioinformatics.

Background: The etiology of gallstone disease (GSD) has not been fully elucidated. Consequently, the primary objective of this study was to scrutinize and provisionally authenticate the distinctive expression profiles of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in GSD. Methods: RiboNucleic Acid (RNA) sequencing was used on four paired human gallbladder samples for the purpose of this study. Differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) were identified and subjected to analysis of their biological functions. The Pearson's correlation coefficients between DElncRNAs and DEmRNAs were computed to construct a co-expression network delineating their associations. Furthermore, both cis- and trans-regulatory networks of selected lncRNAs were established and visualized. Additionally, a competing endogenous RNA (ceRNA) regulatory network was constructed. To validate the RNA-sequencing data, we performed a Quantitative Real-time Polymerase Chain Reaction (RT-qPCR) on 10 paired human gallbladder samples, assessing the expressions of the top 4 DEmRNAs and DElncRNAs in gallstone and control samples. Results: A total of 934 DEmRNAs and 304DElncRNAs were successfully identified. Functional enrichment analysis indicated a predominant involvement in metabolic-related biological functions. Correlation analysis revealed a strong association between the expressions of 597 DEmRNAs and 194 DElncRNAs. Subsequently, both a cis-lncRNA-mRNA and a trans-lncRNA-Transcription Factor (TF)-mRNA regulatory network were meticulously constructed. Additionally, a ceRNA network, comprising of 24 DElncRNAs, 201 DEmRNAs, and 120 predicted miRNAs, was established. Furthermore, using RT-qPCR, we observed significant upregulation of AC004692.4, HECW1-IT1, SFRP4, and COMP, while LINC01564, SLC26A3, RP1-27K12.2, and GSTA2 exhibited marked downregulation in gallstone samples. Importantly, these findings were consistent with the sequencing. Conclusion: We conducted a screening process to identify DElncRNAs and DEmRNAs in GSD. This approach contributes to a deeper understanding of the genetic factors involved in the etiology of gallstones.

Ionized copolyesters with pH-responsive degradability: Accelerated degradation in specific environments.

The development of environmentally responsive biodegradable polymers is a promising solution for balancing the stability and degradability of biodegradable plastics. In this study, a commercial biodegradable polyester, poly(butylene adipate-co-butylene terephthalate) (PBAT), was used as the substrate and was synthetically modified with a small amount of anionic sodium 1-3-isophthalate-5-sulfonate (SIPA) to obtain the ionized random poly(butylene adipate-co-butylene terephthalate-co-butylene 5-sodiosulfoisophthalate) (PBATS). The introduction of the sodium sulfonate ionic group enhanced the mechanical and heat-resistant properties of the material, while significantly improving the hydrophilicity and water absorption of the copolyesters of PBATSs and endowing them with special pH-responsive degradation properties. Compared with PBAT, PBATS copolyesters could accelerate degradation in acidic or alkaline buffer solutions and natural seawater, while degradation was inhibited in neutral buffer solutions at pH 7.2. Degradation experiments in simulated gastric, intestinal, and body fluids revealed that the copolyester showed specific and rapid degradation in acidic gastric fluids. This environmentally-responsive degradable material greatly expands the special applications of biodegradable polyesters in the fields of environmental remediation and medical applications.

Water-soluble biodegradable polyesters with pH and ionic responsivity.

The synthesis of novel water-soluble polymers with biodegradability is an effective way to mitigate their negative environmental impacts. In this study, semi-aromatic copolyester poly(butylene succinate-co-butylene terephthalate) (PBST) with exceptional biodegradability is used as the resin matrix. Anionic sodium 1-3-isophthalate-5-sulfonate (SIPA) is introduced as a fourth monomer to prepare random poly(butylene succinate-co-butylene terephthalate-co-butylene 5-sodiosulfoisophthalate) (PBSTS) copolyesters by melt copolymerization. The incorporation of ionic groups enhances the hydrophilicity and water absorption of the copolyesters, resulting in water-soluble materials that exhibit ionic and temperature responsivity. Furthermore, the ionized biodegradable copolyesters demonstrate distinct pH-dependent degradation, which is accelerated at pH = 5.5 and 8.5 but inhibited at pH = 7.2. Degradation assessments in simulated body fluids reveal that the PBSTS copolyesters exhibit significant degradation in gastric fluids at pH = 1.5 with minimal degradation in intestinal fluids at pH = 6.8 and in body fluids at pH = 7.0. This unique degradation performance highlights the potential of these materials for addressing the challenges associated with selective drug delivery and localized controlled release in the human body.

All-natural environmentally degradable poly (butylene terephthalate-co-caprolactone): A theoretical and experimental study of its degradation properties and mechanisms.

The design and production of materials with excellent mechanical properties and biodegradability face significant challenges. Poly (butylene terephthalate-co-caprolactone) copolyesters (PBTCL) is obtained by modifying the engineering plastic polybutylene terephthalate (PBT) with a simple one-pot process using readily biodegradable ε-caprolactone (ε-CL). The material has mechanical properties comparable to those of commercial biodegradable copolyester PBAT. Besides, this copolyester exhibited remarkable degradability in natural environments such as soil and ocean, for example, PBTCL1.91 lost >40 % of its weight after 6 months of immersion in the Bohai Sea. The effect and diversity of specific microorganisms acting on degradation in the ocean were analyzed by 16 s rDNA gene sequencing. Theoretical calculations such as Fukui function and DFT, and experimental studies on water-soluble intermediates and residual matrixes produced after degradation, confirmed that the insertion CL units not only act as active sites themselves susceptible to hydrolysis reactions, but also promote the reactivity of ester bonds between aromatic segments. This work provides insight for the development of novel materials with high performance and environmental degradability.

Fluorescence tracing the degradation process of biodegradable PBAT: Visualization and high sensitivity.

Biodegradable plastics have emerged as a potential solution to the mounting plastic pollution crisis. However, current methods for evaluating the degradation of these plastics are limited in detecting structural changes rapidly and accurately, particularly for PBAT, which contains worrying benzene rings. Inspired by the fact that the aggregation of conjugated groups can endow polymers with intrinsic fluorescence, this work found that PBAT emits a bright blue-green fluoresces under UV irradiation. More importantly, we pioneered a degradation evaluation approach to track the degradation process of PBAT via fluorescence. A blue shift of fluorescence wavelength as the thickness and molecular weight of PBAT film decreased during degradation in an alkali solution was observed. Additionally, the fluorescence intensity of the degradation solution increased gradually as the degradation progressed, and was found to be exponentially correlated with the concentration of benzene ring-containing degradation products following filtration with the correlation coefficient is up to 0.999. This study proposes a promising new strategy for monitoring the degradation process with visualization and high sensitivity.

Enhanced degradation of poly(ethylene terephthalate) by the addition of lactic acid / glycolic acid: composting degradation, seawater degradation behavior and comparison of degradation mechanism.

The degradability improvement of poly(ethylene terephthalate) (PET), one of the most widely used but non-degradable disposable packaging material, is of great significance. However, the balance between degradability and mechanical properties remains a huge challenge. Herein, simple hydroxy acids, lactic acid (LA) and glycolic acid (GA) as easy hydrolysis sites were introduced into non-degradable PET via melt polycondensation. A series of high molecular weight poly(ethylene terephthalate-co-L­lactide) (PETL) and poly(ethylene terephthalate-co-glycolate) (PETG) copolyesters were synthesized with an excellent tensile strength greater than 50 MPa, much higher than that of most commercially available degradable polymers. The introduction of hydroxy acid endows PET with significantly improved composting and seawater degradation performance. Furtherly, the degradation rate of PETG with hydrophilic GA unit was faster than that of PETL, and the mineralization rate of PETG80 reaches 22.0%. The density of functional theory (DFT) calculation revealed that adding hydroxy acid to the PET molecular chain reduced the energy barrier of the hydrolysis reaction. The molecular polarity index (MPI) analysis furtherly confirmed that the higher affinity between the GA unit and water may be the primary reason for the faster degradation of PETG.

Screening for and combining serum intestinal barrier-related biomarkers to predict the disease severity of AECOPD.

BACKGROUND: In the patients with AECOPD, the gut displays ischemia, anoxia and oxidative stress, which lead to the intestinal barrier failure. Therefore, it is desirable to screen for effective intestinal barrier-related biomarkers to monitor the disease severity. METHODS: We conducted a prospective observational study in 40 patients with AECOPD and 10 patients with stable COPD. The serum levels of I-FABP, citrulline, D-Lactate, DAO, and α-GST, as well as the APACHE II scores were recorded. Person correlation analysis, logistic regression models and receiver operating characteristic (ROC) curve analyses were used in our study. RESULTS: Patients with AECOPD had significantly higher levels of I-FABP, D-Lactate, and DAO than did those with stable COPD. However, the serum citrulline level was significantly decreased in the patients with stable COPD than in those with AECOPD and the serum α-GST was not significantly changed. Additionally, we observed that there was a higher levels of I-FABP, D-Lactate, and DAO and a lower level of citrulline in patients with severe COPD than in patients with nonsevere COPD [APACHE II (nonsevere COPD) <20; APACHE II (severe COPD) ≥20]. Correlation analysis showed that I-FABP and D-Lactate had a significantly positive correlations with the APACHE II score, and citrulline had a significantly negative correlations with the APACHE II score. Following, treatment, the levels of I-FABP and D-lactate were decreased and the level of citrulline was increased. Moreover, we screened out the citrulline and DAO, which independently affected the diagnosis of severe COPD by stepwise logistics regression analysis. Additionally, we found that the combination of serum citrulline and DAO can more effectively diagnose the severe COPD than any single biomarker can, which may be a supportive and convenient method that can be used clinically. CONCLUSIONS: Serum I-FABP, citrulline and D-Lactate could be used to assess the disease severity. Citrulline and DAO can diagnose the severe COPD and the combination is more effective.

Influence of Silica Particle Size on the Corrosion Behavior of Electroplated Silica-Ni Hybrid Layer.

Silica-Ni hybrid layers were electroplated on a Q235 steel plate in a Watt nickel plating solution with varying sizes of silica, and a pure nickel layer was prepared as a blank sample. The surface morphology, composition, and crystal structure of the electroplated layers were examined using a field emission scanning electron microscope (FESEM), an energy-dispersive spectrometer (EDS), and a X-ray diffractor (XRD). The corrosion resistance of the samples was evaluated by the experiments of potentiodynamic polarization, electrochemical impedance spectroscopy, and salt spray test in NaCl solutions. The results showed that the smaller the particle size of silicon, the higher the content of silicon in the layer was, and the better the corrosion resistance of the layer was. However, when the particle size is 10 nm, agglomeration would happen, which leads to a decrease in the corrosion resistance performance, 50 nm silica-Ni hybrid layer showed the optimal corrosion resistance with the highest silica content.

MSC-derived exosomal miR-34a/c-5p and miR-29b-3p improve intestinal barrier function by targeting the Snail/Claudins signaling pathway.

AIMS: Mesenchymal stem cell (MSC)-derived exosomes (MSCs-exos) regulate biological functions in different diseases, such as liver fibrosis, diabetes, and ischaemic heart injury. However, the function of MSC-derived exosomes on the intestinal barrier and the underlying mechanisms are poorly characterized. MAIN METHODS: The expression of miR-34a/c-5p, miR-29b-3p and Claudin-3 in human normal intestinal tissues and damaged intestinal tissues was evaluated by RT-qPCR. The effect of MSC-secreted exosomes on Claudins in Caco-2 cells was measured by using confocal microscopy, RT-qPCR and Western blot. Dual luciferase reporter assays and RNA immunoprecipitation (RIP) assays were performed to study the interaction between miR-34a/c-5p, miR-29b-3p and Snail. I/R-induced intestinal damage in rats was used to determine the in vivo effect of MSC-exos on intestinal barrier function. KEY FINDINGS: In this study, we found that miR-34a/c-5p, miR-29b-3p and Claudin-3 were downregulated in damaged human intestinal tissues. MSC-exos increased the expression of Claudin-3, Claudin-2 and ZO-1 in Caco-2 cells. Further studies demonstrated that MSC-exos promoted Claudin-3, Claudin-2 and ZO-1 expression in Caco-2 cells by Snail, which was targeted by miR-34a/c-5p and miR-29b-3p. In vivo experiments showed that MSC-derived exosomes could improve I/R-induced intestinal damage through the Snail/Claudins signaling pathway. SIGNIFICANCE: The findings here suggest a novel molecular basis for the therapy of intestinal barrier dysfunction.