Enhanced Acetone-Sensing Properties of Pt-Decorated In2O3 Hollow Microspheres Derived from Pt-Embedded Template.

Pt-decorated In2O3 hollow microspheres were prepared using a template and reflux method. The size of the prepared carbon templates was adjusted from 200 nm to 1.3 µm by introducing chloroplatinic acid during the hydrothermal process. At the same time, Pt nanoparticles inside the carbon layer were protected from oxidation and agglomeration. Also, the folds created on the surface of the hollow sphere during shrinkage led to a substantial increase in specific surface area. The response of the In2O3-based sensor toward acetone was significantly enhanced by the addition of Pt decoration. This improvement can be attributed to the increased availability of active sites for the target gas and the consequential alteration of the energy band structure. In addition, high response sensitivity, rapid dynamic processes, long-term reliability, and selectivity have all been achieved. The detectable limit is less than 1 ppm, which might satisfy the 1.8 ppm threshold value in the exhaled breath of patients with diabetes. Consequently, the proposed sensor has great sensitivity and can detect low-concentration of acetone, making it an ideal choice for applications such as monitoring daily dietary intake, managing diabetes, and inspecting industrial production processes.

Ultrasensitive and Exclusive Chemiresistors with a ZIF-67-Derived Oxide Cage/Nanofiber Co3O4/In2O3 Heterostructure for Acetone Detection.

Gas sensors for acetone detection have received considerable attention because acetone has a significant influence on both the environment and human health, e.g., it is flammable and toxic and may be related to blood glucose levels. However, achieving high sensitivity and selectivity at low concentrations is still a great challenge to date. Here, we report a unique chemiresistive gas sensor for acetone detection, which is composed of In2O3 nanofibers loaded with a porous Co-based zeolitic imidazolate framework (ZIF-67)-derived Co3O4 cage prepared by simple electrospinning and solvothermal methods. The ZIF-67-derived oxide cage/nanofiber Co3O4/In2O3 heterostructure has abundant reversible active adsorption/reaction sites and a type-I heterojunction, resulting in an ultrasensitive response of 954-50 ppm acetone at 300 °C. In addition, it demonstrates a low detection limit of 18.8 ppb, a fast response time of 4 s, good selectivity and repeatability, acceptable humidity interference, and long-term stability. With such excellent sensing performance to acetone, our chemiresistive gas sensor could be potentially applied for environmental monitoring and early diagnosis of diabetes.

Validation of an Ion-Pair Reverse Phase High-Performance Liquid Chromatography Method for the Detection of Major Components and Related Substances in Diquafosol Sodium Eye Drops.

A simple, feasible, isocratic elution, and stable reversed-phase high performance liquid chromatography method was established and verified. The chromatographic conditions are as follows: EF-C18H, 4.6 × 250 mm, 5 µm column; column temperature 30 °C; for the mobile phase 27.2 g of KH2PO4 and 8.5 g of tetrabutylammonium hydrogen sulfate were taken, 2500 mL of water was added to dissolve, and the pH was adjusted to 6.7 with phosphoric acid:methanol solution with a ratio of 84:16 (V:V). The flow rate was 1.0 mL/min; the injection volume was 10 µL; and the wavelength was 262 nm. According to the current ICH guidelines, the developed method was verified, and the system suitability, specificity, LOD, LOQ, linearity, range, accuracy, repeatability, durability, and solution stability of the proposed method were verified. The validation results demonstrated that the LOQ for the method was 0.05% and the LOD was 0.02%. The content was detected within the concentration range of 300 to 900 µg/mL. The relationship between concentration and measurement was linear, with an r2 of >0.999. The concentration of impurities ranged from 0.3 to 4.5 µg/mL. A good linear correlation was observed within the range of g/mL, with a coefficient of determination r2 greater than 0.999. The accuracy and repeatability met the specified criteria.

Exceptional crystallization diversity and solid-state conversions of Cd(II) coordination frameworks with 5-bromonicotinate directed by solvent media.

A series of nine coordination polymers {[Cd(L)(2)(solvent)(x)](solvent)(y)}(n) have been prepared from Cd(NO(3))(2) and 5-bromonicotinic acid (HL) in different solvents through a layered diffusion method. By using CH(3)OH/H(2)O at different volume ratios of 1:1 and 1:3, a one-dimensional (1D) coordination species (1a) and a three-dimensional (3D) (3,6)-connected framework (2a·g(1)) can be obtained. A similar self-assembly process in C(2)H(5)OH/H(2)O or H(2)O/1,4-dioxane gives 2a·g(2) or 2a·g(3), which are isomorphic to 2a·g(1) but with different lattice solvents. Replacement of the mixed solvents with DMF/H(2)O (v/v 1:1 or 1:3) also gives a 1D chain complex (1b) or a 3D microporous framework (2b·g(1)). Similarly, MOF 2b·g(2) can be assembled from CH(3)CN/H(2)O as an isomorphic solvate of 2b·g(1). Significantly, the 3D MOF families of 2a·g(n) and 2b·g(n) are supramolecular isomers even though they are topologically equivalent. Also, if a mixture of CH(3)OH/CH(2)Cl(2) (v/v 1:1 or 3:1) is used, a pair of distinct MOFs (3a·g) and (3b) are generated as pseudo-polymorphs that show a two-dimensional (2D) sheet and a 3D coordination framework, respectively. Furthermore, mutual solvent-induced conversions were realized between 1a and 1b and between 2a·g(1), 2a·g(2), and 2a·g(3) following the size-dependent rule of the solvent. These results are of great significance in recognizing the solvent effect upon coordination assemblies and their crystal transformations.

[Molecular epidemiological characteristics of clinically isolated carbapenem-resistant Acinetobacter baumannii in Changsha].

OBJECTIVE: To survey antibiotic resistance of clinical isolates of Acinetobacter baumannii in Changsha and to investigate molecular epidemiological characteristics of carbapenem-resistant Acinetobacter baumannii. METHODS: A total of 205 non-duplicated, clinical isolates of Acinetabacter baumannii from 10 general hospitals in Changsha were collected from March 2010 to December 2010. The K-B disk diffusion method was applied for the drug-susceptibility test; a modified, double-disk synergy test was used to detect metallo-ß-lactamase (MBL), and a modified Hodge test was used for the screening of carbapenemase. PCR was used to amplify carbapenemase genes (including OXA-23, OXA-24, OXA-51, IMP-1, and VIM-2) and the positive products were sequenced. Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) was used for DNA typing and test of homology. RESULTS: Of the 18 antibiotics tested, 14 had a high rate of resistance (>50% of the isolates tested), with piperacillin the highest (80.5% of strains), and cefoperazone/sulbactam the lowest (2.5%). In total, 115 carbapenem-resistant Acinetobacter baumannii strains were confirmed, but their MBL phenotype and genes were all negative. Seventy-one positive strains were detected by the modified Hodge test, among which 64 strains were OXA-23-positive. All the 115 strains were positive for the amplification of the OXA-51 gene, and no strain was found which carried OXA-24 or OXA-58 gene. Seven genomic types were included in the 115 Acinetobacter baumannii. The major prevalence types were Type B ( 72 strains) and Type A (19 strains). CONCLUSION: Multiple drug resistance of clinically isolated Acinetobacter baumannii is a serious problem in Changsha. Production of OXA-23 and OXA-51 carbapenemases is an important mechanism of resistance to carbapenem antibiotics, and there is prevalence of the same clones in these carbapenem-resistant strains.

[NDM-1-producing Klebsiella pneumoniae in mainland China].

OBJECTIVE: To investigate the characteristics of New Delhi metallo-beta-lactamase-1 (NDM-1) gene of Klebsiella pneumoniae (K. pneumoniae) emerging in Hunan, and its relationship to antibiotic resistance. METHODS: The clinical strain was isolated from a sputum sample of a child with severe pnemonia and toxic myocarditis who was admitted into a general hospital of Hunan Province. VITEK-2 compact instrument was used for bacterial identification and antibiotic susceptibility test. Modified Hodge test was used for the screening of carbapenemase. EDTA-synergy test and combination disk diffusion test were used for detection of metallo-ß-lactamase (MBL). PCR was performed for amplification of NDM-1 genes and the positive products were sequenced and analyzed with BLAST. Conjugation was also performed to analyze mechanisms of antibiotic resistance. The results of antibiotic susceptibility tests were compared before and after conjugation. RESULTS: The isolated strain was identified as K.pneumoniae. Modified Hodge test, EDTA-synergy test and combination disk diffusion test were all positive for the strain. The homology between gene sequence of PCR amplification products and NDM-1 gene FN396876.1 in the GenBank was 100%. Transconjugant DNA was used as template for the amplification of NDM-1 gene. The amplification products were sequenced and found to be the same as the NDM-1 gene amplification product of the donor strain. The MIC of transconjugant E.coli J53 (NDM-1) to all the ß-lactams increased significantly compared with the recipient strain E.coli J53. The MIC of ertapenem and imipenem increased by more than 8 times, while the MIC of ceftazidime and ceftriaxone increased by more than 64 times. CONCLUSIONS: This study first identified a strain of K. pneumoniae carrying NDM-1 in mainland China. NDM-1 gene can be transmitted among different strains and causes extensively drug-resistance to ß-lactams.

Characteristics of Activation Rate and Damage of Ion-Implanted Phosphorous in 4H-SiC after Different Annealing by Optical Absorption.

We investigated the ellipsometer-based characterization method being used to quickly evaluate the depth of the damage layer in ion-implanted 4H-SiC. This method had the advantages of low cost, convenience, and non-destructiveness. Optical absorption of n-type 4H-SiC substrate, P+ ion-implanted, laser-annealed, and conventional high-temperature annealed wafers were investigated at room temperature. Three peaks were observed in the absorption spectra collected for various samples. The degree of electrical activation after laser annealing or high-temperature annealing was evaluated qualitatively from the absorption peak intensity at 2.67 eV. The circular transmission line method (CTLM) results were consistent with the optical absorption results. However, it was found that the effective carrier concentration after laser annealing was significantly lower than that after high-temperature annealing.

Inducing effect of additive agents on coordination assembly of silver(I) nitrate with 3,5-bis(2-pyridyl)-4-amino-1,2,4-triazole: supramolecular isomerism and interconversion.

By using different organic acids as additive agents, hydrothermal reactions of AgNO(3) with 3,5-bis(2-pyridyl)-4-amino-1,2,4-triazole (2-bpt) lead to formation of two conformational polymorphs of [Ag(2-bpt)](NO(3)) with bimetallocyclic and 1-D helical coordination patterns. Interconversion between the two supramolecular isomers can be achieved under proper conditions, which will pass through the same intermediate state.

3,4-Bis(2-pyrid-yl)-5-(3-pyrid-yl)-4H-1,2,4-triazole.

In the title mol-ecule, C(17)H(12)N(6), the 2-pyridyl rings in the 3- and 4-positions and the 3-pyridyl ring in the 5-position make dihedral angles of 29.78 (16), 67.06 (16) and 32.97 (16)°, respectively, with the triazole group. The dihedral angle between the two 2-pyridyl rings is 65.72 (15)°. The dihedral angles between the 3-pyridyl ring and the two 2-pyridyl rings in the 3- and 4-positions are 61.28 (15) and 63.11 (15)°, respectively. In the crystal, C-H⋯π and π-π inter-actions [centroid-centroid distance = 3.6248 (19) Å] link the mol-ecules, forming a two-dimensional network.

2,5-Bis(5-methyl-pyrazin-2-yl)-1,3,4-oxadiazole.

In the title mol-ecule, C(12)H(10)N(6)O, the dihedral angle between the two pyrazine rings [planar to within 0.009 (3) and 0.018 (3) Å] is 5.62 (15)°. They deviate from the central oxadiazole ring [planar to within 0.005 (3) Å] by 1.52 (16) and 5.55 (17)°, respectively. In the crystal, C-H⋯N inter-actions involving the pyrazine rings connect mol-ecules to form zigzag supramolecular chains propagating in [010].

Facile preparation of collagen fiber-glycerol-carboxymethyl cellulose composite film by immersing method.

Carboxymethyl cellulose (CMC) and glycerol were added by immersing neutralized collagen fiber paste into CMC/glycerol aqueous solutions with different mass ratios, forming composite films. CMC decreased the glycerol adsorption by 49.5%. The presence of CMC formed rougher film surface and more compact internal structure. Glycerol increased the distances between collagen molecules and decreased the relative triple helix contents. The tensile strength and Young's modulus of film in dry condition maximum respectively increased by 125% and 277% with the immersion in CMC (1.5%)/glycerol (4%) solution, compared to the sample immersed into pure glycerol solution, but mechanical properties decreased at high glycerol content. Besides, lower wet mechanical strength was observed as the addition of CMC, corresponding to the higher water swelling ratio of film. CMC also improved the shrinkage stability under boiling and the thermostability of film at a fixed glycerol level, but higher glycerol content caused the decrease of denaturation temperature of film.

Overexpression of Sirt6 promotes M2 macrophage transformation, alleviating renal injury in diabetic nephropathy.

In this study, we aimed to investigate the associations between Sirt6, macrophages and diabetic nephropathy (DN). Immunohistochemical, western blot and RT­qPCR analyses were performed to detect the expression levels of Sirt6, the markers of podocytes and monocytes and related inflammatory factors in the tissues of rats with streptozocin­induced DN. A series of cell experiments in isolated culture or the co­culture of macrophages and podocytes were conducted to examine the effects of the overexpression of Sirt6 on macrophage transformation, podocyte apoptosis and associated genes, and analyses were performed using RT­qPCR, flow cytometry and western blot analysis, where appropriate. In the rat model of DN, injured podocytes were represented by the decreased protein expression levels of Nephrin and Sirt6, and by an increased Desmin expression. Additionally, the M1 phenotype transformation of macrophages was evidenced by the increased expression levels of CD86, tumor necrosis factor (TNF)­α and inducible nitric oxide synthase (iNOS), and by the decreased expression levels of CD206, Sirt6, interleukin (IL)­4 and IL­10. In vitro assays of macrophages and podocytes demonstrated that glucose promoted macrophage M1 transformation and podocyte apoptosis in a dose­dependent manner and attenuated Sirt6 expression. Macrophages transformed into the M2 phenotype following the overexpression of Sirt6 by the successful transfection of macrophages with a Sirt6 overexpression plasmid. Sirt6 was also overexpressed in podocytes. In a Transwell co­culture system, the overexpression of Sirt6 in macrophages (but not the overexpression of Sirt6 in podocytes) protected the podocytes from high­glucose­induced injury. However, the apoptosis of the podocytes overexpressing Sirt6 (induced by transfection with a Sirt6 overexpression plasmid) still increased when these podocytes were co­cultured with macrophages in high­glucose medium. These protective effects were evidenced by the inhibition of apoptosis, the upregulation of the expression levels of Bcl­2 and CD206, as well as by the decreased expression levels of Bax and CD86. On the whole, the findings of this study suggest that Sirt6 protects podocytes against injury in a mimicked diabetic kidney microenvironment by activating M2 macrophages, indicating that Sirt6 can act as an immune response regulatory factor in DN­associated renal inflammatory injury.

Therapeutic efficacy of milrinone in the management of enterovirus 71-induced pulmonary edema.

Hand, foot, and mouth disease and herpangina are the major clinical manifestations of enterovirus 71 (EV71) infections. Brain-stem encephalitis and pulmonary edema are severe complications that can lead to death. This study was designed to evaluate the potential therapeutic effect of milrinone, a phosphodiesterase (PDE) inhibitor, in the treatment of patients with EV71-induced pulmonary edema. We conducted a historically controlled trial of 24 children with severe EV71-induced pulmonary edema from April 1998-June 2003 in southern Taiwan. Patients were divided into groups treated before and after the introduction of milrinone therapy. Etiological diagnosis was established by viral cultures and confirmed by specific immunofluorescence and neutralization tests. All 24 patients were below 5 years of age. The mortality was lower in the milrinone-treated vs. nontreated group (36.4% vs. 92.3%, P=0.005). Sympathetic tachycardia was decreased in patients treated with milrinone compared to controls (144 +/- 17/min vs. 206 +/- 26/min, P=0.004). A marked decrease in IL-13 (77 +/- 9 pg/ml vs. 162 +/- 88 pg/ml, P=0.001) was observed in milrinone-treated patients compared to controls. There was a significant reduction in white blood cell (10,838 +/- 4,537/mm3 vs. 19,475 +/- 7,798/mm3, P=0.009) and platelet (257 +/- 45 x 10(3)/mm3 vs. 400 +/- 87 x 10(3)/mm3, P=0.001) counts in milrinone-treated patients compared to controls. These results were associated with improvement in sympathetic regulation and decrease in IL-13 production. Milrinone therapy may provide a useful therapeutic approach for this highly lethal disorder.

[Pharmacokinetic study of intraperitoneal chemotherapy with HCPT].

OBJECTIVE: To study the pharmacokinetic of 10-Hydroxycamptothecin HCPT by intraperitoneal administration. METHOD: Six dogs were given HCPT by intraperitoneal perfusion: HCPT 2 mg x kg(-1), dissolved in 300 mL NS. During the course of experiments, peritoneal fluids and blood were sampled using a standardized protocol. The concentration of HCPT in all samples was determined by high performance liquid chromatography (HPLC). RESULT: The area under the curve (AUC) of peritoneal fluids was significantly highly as compared to the AUC of femoral vein and portal vein (P < 0.001). CONCLUSION: These experiments demonstrate that intraperitoneal chemotherapy has significant effect on the pharmacokinetics of IP route of HCPT administration. This method should be a more reasonable chemotherapy for the prevention of recurrence and liver metastasis of gastric cancer, colon cancer and ovary cancer after radical resection.

Destruction and reconstruction of the robust [Cu2(OOCR)4] unit during crystal structure transformations between two coordination polymers.

This work first demonstrates that the robust [Cu(2)(OOCR)(4)] unit can be destroyed and reconstructed in the solid state, as observed in water-induced structural interconversion of two distinct coordination polymers with 5-bromonicotinate.