Enhanced heterogeneous interface to construct intelligent conductive hydrogel gas sensor for individualized treatment of infected wounds

In this study, we developed an enhanced heterogeneous interface intelligent conductive hydrogel NH3 sensor for individualized treatment of infected wounds. The sensor achieved monitoring, self-diagnosis, and adaptive gear adjustment functions. The PPY@PDA/PANI(3/6) sensor had a minimum NH3 detection concentration of 50 ppb and a response value of 2.94 %. It also had a theoretical detection limit of 49 ppt for infected wound gas. The sensor exhibited a fast response time of 23.2 s and a recovery time of 42.9 s. Tobramycin (TOB) was encapsulated in a self-healing QCS/OD hydrogel formed by quaternized chitosan (QCS) and oxidized dextran (OD), followed by the addition of polydopamine-coated polypyrrole nanowires (PPY@PDA) and polyaniline (PANI) to prepare electrically conductive drug-loaded PPY@PDA/PANI hydrogels. The drug-loaded PPY@PDA/PANI hydrogel was combined with a PANI/PVDF membrane to form an enhanced heterogeneous interfacial PPY@PDA/PANI/PVDF-based sensor, which could adaptively learn the individual wound ammonia response and adjust the speed of drug release from the PPY@PDA/PANI hydrogel with electrical stimulation. Drug release and animal studies demonstrated the efficacy of the PPY@PDA/PANI hydrogel in inhibiting infection and accelerating wound healing. In conclusion, the gas-sensitive conductive hydrogel sensing system is expected to enable intelligent drug delivery and provide personalized treatment for complex wound management.

Mutations in chronic myelomonocytic leukemia and their prognostic relevance

Chronic myelomonocytic leukemia (CMML) is a hematologic malignancy that overlaps with myeloproliferative neoplasms (MPN) and myelodysplastic syndromes (MDS) and tends to transform into acute myeloid leukemia (AML). Among cases of CMML, > 90% have gene mutations, primarily involving TET2 (~ 60%), ASXL1 (~ 40%), SRSF2 (~ 50%), and the RAS pathways (~ 30%). These gene mutations are associated with both the clinical phenotypes and the prognosis of CMML, special CMML variants and pre-phases of CMML. Cytogenetic abnormalities and the size of genome are also associated with prognosis. Meanwhile, cases with ASXL1, DNMT3A, NRAS, SETBP1, CBL and RUNX1 mutations may have inferior prognoses, but only ASXL1 mutations were confirmed to be independent predictors of the patient outcome and were included in three prognostic models. Novel treatment targets related to the various gene mutations are emerging. Therefore, this review provides new insights to explore the correlations among gene mutations, clinical phenotypes, prognosis, and novel drugs in CMML.

Influenza a virus and Streptococcus pneumonia coinfection potentially promotes bacterial colonization and enhances B lymphocyte depression and reduction

Influenza has frequently been epidemic in recent years. However, the mechanisms of severe pneumonia with postinfluenza Streptococcus pneumoniae (SP) secondary infection have not been fully understood. In this study, we explored the mechanisms of pneumonia in postinfluenza A virus (IAV) infection via a mouse model. Mice were intranasally inoculated with SP three days after IAV inoculation. We then collected samples at three time points to dynamically observe the pathological progression. In IAV infection alone, lymphocyte infiltration and widened alveolar intervals were observed. In the blood, levels of the CD19+, CD19+CD21+ and CD19+CD79β+B lymphocyte subpopulations were reduced, and IFN-γ and IL-10 were elevated. Slight atrophy was seen in the spleen, which was due to splenic B lymphocyteinitiated apoptosis through the mitochondrial pathway. When SP infection occurred after IAV infection, the pulmonary inflammation was significantly aggravated; a fair number of lymphocytes and neutrophils infiltrated simultaneously with exfoliated bronchial epithelial cells, vascular endothelial cells, widened alveolar septum and hemorrhaging. Increasing edema fluid and bacteria accumulated in the alveolar cavity. Decreased CD19+, CD19+CD21+ and CD19+CD79β+B lymphocyte subpopulations and increased interferon gamma (IFN-γ) or interleukin 10 (IL-10) were more prominent compared to those with viral infection alone. Spleen atrophy resulting from coinfection was more obvious because of massive splenic B lymphocyte apoptosis through the mitochondrial pathway compared to viral infection alone. This study shows that although inflammation caused by SP infection alone was temporary, preceding IAV infection provided favorable conditions for SP colonization and multiplication by destroying lung structure and suppressing humoral immunity. Synergistic IAV-SP coinfection is likely to facilitate more SP colonization and promote B lymphocyte-suppression and reduction. Eventually, the pneumonia worsened.

Compact Yttria-Stabilized Zirconia Based Total NOx Sensor with a Dual Functional Co3O4/NiO Sensing Electrode

Yttria-stabilized zirconia (YSZ) based potentiometric gas sensors have been widely utilized for detecting NO_x (NO and NO₂). Nevertheless, it is still remains challenging issue for YSZ-based sensors to sense total NO_x due to the opposite response signals to NO and NO₂. Herein, we report an efficient strategy to sense total NO_x at high temperature (above 300 °C) by designing a dual functional sensing electrode (SE); namely, the SE will simultaneously convert NO (in NO_x mixture) to NO₂ and electrocatalyze all of the obtained NO₂ to generate the response signal of total NO_x. In comparison with those previously reported total NO_x sensors, the proposed total NO_x sensor will be featured with a simplified sensor configuration and desirable long-term stability. To confirm the practicability of the proposed strategy, the NO conversion rate of several metal oxides and their composites have been measured and it turns out that the Co₃O₄/NiO shows relatively high NO conversion rate. Further study indicates a YSZ-based sensor consisting of (Co₃O₄ + 20 wt % NiO)-SE and Mn-based RE demonstrates satisfactory performance in detecting total NO_x. For instance, analogous response magnitude to NO and NO₂ as well as the mixture of NO/NO₂ (within 35 ppm) is witnessed for the sensor; particularly, the sensor gives acceptable stability and response/recovery rate at the operating temperature of 500 °C within the examined period. In summary, the use of dual functional SE (e.g., Co₃O₄/NiO composite SE) indeed addressed those issues of concern in monitoring the level of total NO_x and has provided a promising alternative way for designing future high-performance total NO_x sensor.

Light-Regulated Electrochemical Reaction Assisted Core-Shell Heterostructure for Detecting Specific Volatile Markers with Controllable Sensitivity and Selectivity

Breath analysis has been considered a noninvasive, safe, and reliable way to diagnose cancer at very early stage. Rapid detection of cancer volatile markers in breath samples via a portable sensing device will lay the foundation of future early cancer diagnosis. Nevertheless, unsatisfactory sensitivity and specificity of these sensing devices restrain the clinical application of breath analysis. Herein, we proposed the strategy of designing the light-regulated electrochemical reaction assisted core-shell heterostructure to address the issue of concern; that is, the photoactive shell will be designed for trigging the light-regulated electrochemical reaction and enhancing the sensitivity while a catalytic active core will play the function of removing interference gases. After screening of various core candidates, Fe₂O₃ was found to exhibit relatively low conversion rate to 3-methylhexane, which is one of the representative volatile markers for breath analysis, suggesting that mutual interference would be eliminated by Fe₂O₃. Based on this assumption, an electrochemical sensor comprising core-shell Fe₂O₃@ZnO-SE (vs Mn-based RE) was fabricated and sensing properties to 6 kinds of volatile markers was evaluated. Interestingly, the thickness of ZnO shell significantly influenced the response behavior; typically, the Fe₂O₃@ZnO with shell thickness of 4.8 nm offers the sensor high selectivity to 3-methylhexane. In contrast, significantly mutual response interference is observed for the Fe₂O₃@ZnO with extremely thick/thin shell. Particularly, sensing properties are greatly enhanced upon illumination; a detection limit to 3-methylhexane can even be as low as 0.072 ppm which will be useful in clinic application. Besides, the high selectivity of the sensor to 3-methylhexane is further confirmed by the testing of simulated breath samples. In summary, we anticipate that the strategy proposed in this research will be a starting point for artificially tailoring the sensitivity and selectivity of future sensing devices.

Investigation of energy transfer mechanisms in rare-earth doped amorphous silica films embedded with tin oxide nanocrystals

Three different types of rare earth (RE³⁺) ions-doped silica thin films are fabricated by a soft chemistry-based method. By introducing tin oxide (SnO₂) nanocrystals with larger cross-sections as sensitizers, the characteristic emission intensity of RE³⁺ ions in amorphous silica thin films can be enhanced by more than two orders of magnitude via the energy transfer process. The possible energy transfer processes under different local environment are revealed by using Eu³⁺ ions as an optical probe. Quantitative studies of PL decay lifetime and temperature-dependence PL spectra suggest that the partial incorporation of RE³⁺ ions into SnO₂ sites gives rises to the change of crystal-field symmetry and the significant enhancement of energy transfer efficiency. Further, typical analytical energy dispersive X-ray spectroscopy (EDS) mapping results prove that part of Eu³⁺ ions doped into the SnO₂ sites after annealing at 1000 °C. We anticipate that our results would shed light on the future research on the energy transfer mechanisms under different local structures of RE³⁺ ions.

Transparent thermoplastic polyurethane air filters for efficient electrostatic capture of particulate matter pollutants

Particulate matter (PM) air pollution has been established as a significant threat to public health and a destructive factor to the climate and eco-systems. In order to eliminate the effects of PM air pollution, various air filtering strategies based on electrospun nanofibers have recently been developed. However, to date, almost none of the existing nanofibers based air filters can meet the requirements of high-performance air PM filtering, including high PM removal efficiency, low resistance to airflow, and long service life, etc. For the first time, we report a fabrication process using the electrospinning method for air filters based on thermoplastic polyurethane (TPU) nanofibers. The average diameters of TPU nanofibers are tunable from 0.14 ± 0.06 μm to 0.82 ± 0.22 μm by changing the TPU concentrations in polymeric solutions. The optimized TPU nanofibers based air filters demonstrate the attractive attributes of high PM_2.5 removal efficiency up to 98.92%, good optical transparency of ∼60%, low pressure drop of ∼10 Pa, high quality factor of 0.45 Pa^-1, and long service life under the flow rate of 200 ml min^-1, which is ground-breaking compared with the existing nanofibers based air filters. These TPU nanofibers based air filters, with the excellent filtration performance and light transmittance, will shed light on the future research of nanofibers for various filtration applications and greatly benefit the public health by reducing the effects of PM air pollution.

Batch microfabrication and testing of a novel silicon-base miniaturized reference electrode with an ion-exchanging nanochannel array for nitrite determination

The reference electrode (RE) provides a stable potential for electrochemical detection; therefore, the RE plays an important role in environmental monitoring. In this paper, a novel batch of microfabricated silicon-base miniaturized Ag/AgCl RE was reported. A specially designed mini-tank for saturated KCl solution storage and a nanochannel array for ion-exchange were fabricated on a 4 inch (100) silicon wafer using a two-step KOH anisotropic etching process. An Ag/AgCl electrode was fabricated on a 4 inch Pyrex 7740 glass substrate. Finally, the finished silicon and glass substrates were anode bonded to form the entire system. By comparing with a conventional solid-state Ag/AgCl RE in electrochemical microsensors, a pre-packaged saturated KCl solution in the mini-tank provided a stable working environment for the Ag/AgCl electrode to ensure a constant reference potential. Compared with a routine glass-structured RE and by replacing the ion-exchange membrane with a nanochannel array, the miniaturized RE achieved a longer lifetime. The size of the finished miniaturized RE electrode was 11 mm × 14 mm. The reference potential variation was only 0.1 mV under continuous testing for 3000 s. The standard deviation in the reference potential was only 1.314 mV in different Na₂SO₄ buffer concentrations ranging from 3 mM to 30 mM. To verify the practicality of the novel silicon-base miniaturized RE, the fabricated RE was applied to measure the amount of nitrite in a water sample and achieved a better linearity of R² = 0.998. This miniaturized RE showed better reference potential stability and consistency because of the batch fabrication technique. This novel strategy for the design and manufacture of the miniaturized RE shows a bright future in the wide use of electrochemical sensors in online monitoring of water pollutants.

In this paper, a miniaturized Ag/AgCl reference electrode, which can be mass-produced by micro–nano manufacturing technology, was developed and demonstrated to have good stability and a long lifetime.

High-Performance Limiting Current Oxygen Sensor Comprised of Highly Active La0.75Sr0.25Cr0.5Mn0.5O₃ Electrode

Zirconia-based limiting current oxygen sensor gains considerable attention, due to its high-performance in improving the combustion efficiency of fossil fuels and reducing the emission of exhaust gases. Nevertheless, the Pt electrode is frequently used in the oxygen sensor, therefore, it restrains the broader application due to the high cost. Quite recently, La_0.75Sr_0.25Cr_0.5Mn_0.5O₃ (LSCM) has been reported to be highly active to catalyze oxygen reduction. Herein, with the intention of replacing the frequently used Pt, we studied the practicability of adapting the LSCM to zirconia-based limiting current oxygen sensor. Through comparing the electrocatalytic activity of LSCM and Pt, it is confirmed that LSCM gave analogous oxygen reactivity with that of the Pt. Then, limiting the current oxygen sensors comprised of LSCM or Pt are fabricated and their sensing behavior to oxygen in the range of 2–25% is evaluated. Conclusively, quick response/recovery rate (within 7s), linear relationship, and high selectivity (against 5% CO₂ and H₂O) in sensing oxygen are observed for the sensors, regardless of the sensing materials (LSCM or Pt) that are used in the sensor. Particularly, identical sensing characteristics are observed for the sensors consisting of LSCM or Pt, indicating the practicability of replacing the Pt electrode by adapting the LSCM electrode to future zirconia-based oxygen sensors.

Light-Regulated Electrochemical Sensor Array for Efficiently Discriminating Hazardous Gases

Inadequate detection limit and unsatisfactory discrimination features remain the challenging issues for the widely applied electrochemical gas sensors. Quite recently, we confirmed that light-regulated electrochemical reaction significantly enhanced the electrocatalytic activity, and thereby can potentially extend the detection limit to the parts per billion (ppb) level. Nevertheless, impact of the light-regulated electrochemical reaction on response selectivity has been discussed less. Herein, we systematically report on the effect of illumination on discrimination features via design and fabrication of a light-regulated electrochemical sensor array. Upon illumination (light on), response signal to the examined gases (C₃H₆, NO, and CO) is selectively enhanced, resulting in the sensor array demonstrating disparate response patterns when compared with that of the sensor array operated at light off. Through processing all the response patterns derived from both light on and light off with a pattern recognition algorithm, a satisfactory discrimination feature is observed. In contrast, apparent mutual interference between NO and CO is found when the sensor array is solely operated without illumination. The impact mechanism of the illumination is studied and it is deduced that the effect of the illumination on the discriminating features can be mainly attributed to the competition of electrocatalytic activity and gas-phase reactivity. If the enhanced electrocatalytic activity (to specific gas) dominates the whole sensing progress, enhancements in the corresponding response signal would be observed upon illumination. Otherwise, illumination gives a negligible impact. Hence, the response signal to part of the examined gases is selectively enhanced by illumination. Conclusively, light-regulated electrochemical reaction would provide an efficient approach to designing future smart sensing devices.

Structural Brain Network Reorganization in Patients with Neuropsychiatric Systemic Lupus Erythematosus

BACKGROUND AND PURPOSE

Patients with neuropsychiatric systemic lupus erythematosus have worse outcomes compared with those with systemic lupus erythematosus. A better understanding of the mechanisms of neuropsychiatric systemic lupus erythematosus could potentially improve diagnosis and management. The goal of this study was to investigate the differences in the structural brain network of patients with neuropsychiatric systemic lupus erythematosus compared with patients with systemic lupus erythematosus by using brain connectivity analysis.

MATERIALS AND METHODS

We recruited 20 subjects for each patient cohort and age-matched healthy controls. The topology and efficiency of the network and the characteristics of various brain hubs were investigated by using brain connectivity analysis of diffusion MR imaging data.

RESULTS

There were more extensive reorganizations in the structural brain network of patients with neuropsychiatric systemic lupus erythematosus than in patients with systemic lupus erythematosus. For example, the network of the former had significantly decreased clustering coefficient and local efficiency. They also had significantly lower nodal efficiency in the superior temporal gyrus (P = .046) and middle temporal gyrus (P = .041).

CONCLUSIONS

Our results hint at a plausible relationship between the neuropsychiatric symptoms and reorganization of the structural brain network of patients with systemic lupus erythematosus. Brain connectivity analysis may be a potential tool to subtype these patients.

Associations of serotonin receptor gene HTR3A, HTR3B, and HTR3A haplotypes with bipolar disorder in Chinese patients

Single nucleotide polymorphisms (SNPs) in HTR3A and HTR3B have been reported to be associated with bipolar disorder in European and Japanese populations. We explored the roles of 21 tag SNPs in HTR3A and HTR3B in susceptibility to bipolar disorder in a Chinese cohort. Twenty-one Tag SNPs were genotyped in a study consisting of 130 patients with bipolar disorder, who visited Shandong Mental Health Center between June 2013 and May 2014, and 109 healthy individuals as controls. All of the tag SNPs were genotyped using Sequenom MassArray matrix-assisted laser desorption/ionization time of flight spectrometry. Plink 1.07, Haploview 4.2, and SPSS 20.0 were used for the analysis of the genotypes and the associations of the haplotypes with bipolar disorder. Association analyses of tag SNPs detected significant associations with the A allele in HTR3A rs1176719 (P = 0.030) and the C allele in HTR3A rs1176713 (P = 0.048). Haplotype-based association analyses indicated a statistically significant (P = 0.035) five-SNP haplotype (rs1062613:C, rs11604247:C, rs1176722:G, rs2276302:A, rs1176719:G) of linkage disequilibrium in block 3. Analysis of our small Chinese sample revealed a significant association of HTR3A with bipolar disorder, but yielded no evidence of an association between HTR3B and bipolar disorder. Furthermore, evidence for an association was found for a haplotype of HTR3A. Studies with larger Chinese samples are needed to verify our findings.

Potentiometric NO2 Sensors Based on Thin Stabilized Zirconia Electrolytes and Asymmetric (La0.8Sr0.2)0.95MnO3 Electrodes

Here we report on a new architecture for potentiometric NO₂ sensors that features thin 8YSZ electrolytes sandwiched between two porous (La_0.8Sr_0.2)_0.95MnO₃ (LSM95) layers—one thick and the other thin—fabricated by the tape casting and co-firing techniques. Measurements of their sensing characteristics show that reducing the porosity of the supporting LSM95 reference electrodes can increase the response voltages. In the meanwhile, thin LSM95 layers perform better than Pt as the sensing electrode since the former can provide higher response voltages and better linear relationship between the sensitivities and the NO₂ concentrations over 40–1000 ppm. The best linear coefficient can be as high as 0.99 with a sensitivity value of 52 mV/decade as obtained at 500 °C. Analysis of the sensing mechanism suggests that the gas phase reactions within the porous LSM95 layers are critically important in determining the response voltages.

[The effects of Xuezhikang on serum lipid profile, thromboxane A2 and prostacyclin in patients with hyperlipidemia]

OBJECTIVE

To study the effects of Xuezhikang on lipid profile, thromboxane (TX) A(2), prostacyclin (PGI(2)) in patients with hyperlipidemia.

METHODS

91 patients with hyperlipidemia were randomly divided into a treatment group (n = 47, Xuezhikang 1.2 g/d Bid, p.o) and control group (n = 44, gemfibrozil 1.2 g/d Bid, p.o). serum lipids, TXB(2) and 6-Keto-PGF(1alpha) were determined before and 8 weeks after the treatment.

RESULTS

(1) After 8 weeks of treatment, the level of serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) decreased by 21.6% (P < 0.01) and 33.3% (P < 0. 01) in the Xuezikang group and by 20.4% (P < 0.01) and 24.8% (P < 0.01) in the gemfibrozil group respectively. Serum high density lipoprotein cholesterol (HDL-C) level elevated by 33.7% in the Xuezhikang group (P < 0.01) and 26.9% in the gemfibrozil group (P < 0.01). The effect of Xuezhikang was the same as gemfibrozil. There was no statistically significant difference between the effects of these two drugs. Triglyceride (TG) level decreased by 23.3% in the Xuezhikang group (P < 0.01) and 40.3% in the gemfibrozil group (P < 0.01). TG lowering effect of gemfibrozil was superior to that of Xuezhikang (P < 0.05). (2) The level of lipoprotein (a) [LP (a)] in the plasma decreased by 28.2% (P < 0.01) in the Xuezhikang group and by 4.9% (P > 0.05) in the gemfibrozil group. LP (a) lowering effect of Xuezhikang was superior to that of gemfibrozil (P < 0.01). (3)The Level of thromboxane (TX) B(2) in the plasma decreased by 34.2% in the Xuezhikang group (P < 0.01) and by 8.4% in the gemfibrozil group (P < 0.01). TXB(2) lowering effect of Xuezhikang was superior to that of gemfibrozil (P < 0.01). The level of 6-KetO-PGF(1alpha) in the plasma elevated by 65.4% in the Xuezhikang group (P < 0.01) and by 11.7% in the gemfibrozil group (P < 0.01); the effect of Xuezhikang was superior to that of gemfibrozil (P < 0.01).

CONCLUSION

Xuezhikang could markedly decrease the level of TC and LDL-C and elevate that of HDL-C in patients with hyperlipidemia and the effects of Xuezhikang were the same as those of gemfibrozil. TG lowering effect of gemfibrozil was superior to that of Xuezhikang, but Xuezhikang could markedly decrease the level of Lp (a) and regluate the balance between TXA(2) and PGI(2), its effect being superior to that of gemfibrozil.

A double-stranded RNA element from a hypovirulent strain of Rhizoctonia solani occurs in DNA form and is genetically related to the pentafunctional AROM protein of the shikimate pathway

M2 is a double-stranded RNA (dsRNA) element occurring in the hypovirulent isolate Rhs 1A1 of the plant pathogenic basidiomycete Rhizoctonia solani. Rhs 1A1 originated as a sector of the virulent field isolate Rhs 1AP, which contains no detectable amount of the M2 dsRNA. The complete sequence (3,570 bp) of the M2 dsRNA has been determined. A 6.9-kbp segment of total DNA from either Rhs 1A1 or Rhs 1AP hybridizes with an M2-specific cDNA probe. The sequences of M2 dsRNA and of PCR products generated from Rhs 1A1 total DNA were found to be identical. Thus this report describes a fungal host containing full-length DNA copies of a dsRNA element. A major portion of the M2 dsRNA is located in the cytoplasm, whereas a smaller amount is found in mitochondria. Based on either the universal or the mitochondrial genetic code of filamentous fungi, one strand of M2 encodes a putative protein of 754 amino acids. The resulting polypeptide has all four motifs of a dsRNA viral RNA-dependent RNA polymerase (RDRP) and is phylogenetically related to the RDRP of a mitochondrial dsRNA associated with hypovirulence in strain NB631 of Cryphonectria parasitica, incitant of chestnut blight. This polypeptide also has significant sequence similarity with two domains of a pentafunctional polypeptide, which catalyzes the five central steps of the shikimate pathway in yeast and filamentous fungi.

State of hepatitis B virus DNA in leucocytes of hepatitis B patients

Hepatitis B virus (HBV) DNA in leucocytes from 50 hepatitis patients with various patterns of HBV serological markers and serum HBV DNA and 13 normal controls were examined by Southern blot hybridization with 32P-labeled 3.2 Kb HBV DNA. A free form of HBV DNA was observed in leucocytes of 8 patients, 7 of whom were positive for serum HBeAg, and in 6 patients an integrated form of HBV DNA was identified. HBV DNA was not identified in leucocytes from 13 normal controls. The free form of HBV DNA in leucocytes existed as a heterogeneous smear from 2.0 to 3.2 Kb, similar to the pattern in liver and hepatocellular carcinoma cells but different from serum HBV DNA in which the 3.2 Kb band was absent. The banding pattern of the integrated form of HBV DNA in leucocytes varied among different patients. During preparation of white blood cells and purification of HBV DNA probes, it was important to remove plasma contamination and traces of pBR322, respectively. The presence of extrachromosomal DNA sequences partially homologous to pBR322 could cause false results. The presence of a free and integrated form of HBV DNA in leucocytes is important for explaining the biology of HBV, the harbouring and replication sites of extrahepatic origin, the mechanism of recurrent infection, and the rationale of the treatment of hepatitis B.