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1.
Lett Appl Microbiol ; 75(5): 1064-1073, 2022 Nov.
Article in English | MEDLINE | ID: mdl-34562275

ABSTRACT

Heavy metals are continuously released into aquatic environments in which they accumulate. This phenomenon endangers public health because heavy metals accumulate along the food chain. However, conventional remediation methods are inefficient, expensive and yield toxic intermediate products, which adversely affect the environment. The discovery of green bio-adsorbents such as microbial extracellular polymer substance (EPS) has quickly attracted considerable worldwide attention because of their low cost, high removal efficiency of heavy metals and industrial availability. Hence, this review considers the sources, hazards and treatment methods of heavy metals pollution, particularly the biosorption mechanism of EPS to heavy metals and the influencing factors of the bio-adsorption process, which are significant in the efficient removal of heavy metals-containing wastewater treatment. This review also focuses on strengthening the process of EPS adsorption of heavy metals, which can further contribute to heavy metals removal. Finally, it has been proposed that improving the yield, stability, selectivity and recoverability of EPS is the key direction of further research.


Subject(s)
Metals, Heavy , Water Pollutants, Chemical , Water Purification , Adsorption , Polymers
2.
RSC Adv ; 11(39): 23851-23859, 2021 Jul 06.
Article in English | MEDLINE | ID: mdl-35479024

ABSTRACT

In this study, a facile and environmentally friendly synthesis process was proposed without regular chemical additives. We successfully synthesized spherical gold nanoparticles (AuNPs) coated with glycyrrhizin (GL) by using GL as both a reductant and a stabilizer to reduce chloroauric acid. The obtained NPs were approximately 35 nm in size. The formation of these GL-AuNPs was verified by the presence of a surface plasmon resonance band at 526 nm. We also experimentally determined that in terms of chemical structure, GL can be used as a reducing agent to obtain colloidal gold. The d-glucuronic acid structure, rather than glycyrrhetinic acid (GA), plays an important reducing role in colloidal gold production. From this, we hypothesized that other compounds with sugar structures in Glycyrrhiza may also have the ability to reduce chloroauric acid. To mitigate the high cost and low efficiency of current GL detection methods, we applied AuNPs to the immunochromatographic system. Then, a colloidal gold immunochromatographic test strip based on the indirect competition method was developed for the rapid detection of GL, and the detection limit of this strip was 25 ng mL-1. The cross-test showed that the strip has high specificity. The test results are consistent with the data obtained by high-performance liquid chromatography (HPLC) with a coincidence rate of up to 100%. The rapid test strip is simple, fast, highly efficient and inexpensive, making it suitable for large-scale, rapid glycyrrhizin content determination.

3.
Nanoscale ; 12(18): 10328-10334, 2020 May 14.
Article in English | MEDLINE | ID: mdl-32367087

ABSTRACT

We combine quantum-chemical calculations and molecular dynamics simulations to consider aqueous ion flow across non-axisymmetric nanopores in monolayer graphene and MoS2. When the pore-containing membrane is subject to uniaxial tensile strains applied in various directions, the corresponding permeability exhibits considerable directional dependence. This anisotropy is shown to arise from directed perturbations of the local electrostatics by the corresponding pore deformation, as enabled by the pore edge geometries and atomic compositions. By considering nanopores with ionic permeability that depends on the strain direction, we present model systems that may yield a detailed understanding of the structure-function relationship in solid-state and biological ion channels. Specifically, the observed anisotropic effects potentially enable the use of permeation measurements across strained membranes to obtain directional profiles of ion-pore energetics as contributed by groups of atoms or even individual atoms at the pore edge. The resulting insight may facilitate the development of subnanoscale pores with novel functionalities arising from locally asymmetric pore edge features.

4.
Research (Wash D C) ; 2019: 3054062, 2019.
Article in English | MEDLINE | ID: mdl-31549055

ABSTRACT

We review some recent progress in the exploration of pseudospin-1 physics using dielectric photonic crystals (PCs). We show some physical implications of the PCs exhibiting an accidental degeneracy induced conical dispersion at the Γ point, such as the realization of zero refractive index medium and the zero Berry phase of a loop around the nodal point. The photonic states of such PCs near the Dirac-like point can be described by an effective spin-orbit Hamiltonian of pseudospin-1. The wave propagation in the positive, negative, and zero index media can be unified within a framework of pseudospin-1 description. A scale change in PCs results in a rigid band shift of the Dirac-like cone, allowing for the manipulation of waves in pseudospin-1 systems in much the same way as applying a gate voltage in pseudospin-1/2 graphene. The transport of waves in pseudospin-1 systems exhibits many interesting phenomena, including super Klein tunneling, robust supercollimation, and unconventional Anderson localization. The transport properties of pseudospin-1 systems are distinct from their counterparts in pseudospin-1/2 systems, which will also be presented for comparison.

6.
Eur Rev Med Pharmacol Sci ; 23(6): 2469-2475, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30964173

ABSTRACT

OBJECTIVE: Our study aimed to investigate the expression of microRNA-216a-5p (miR-216a-5p) in breast cancer (BC) and its effect on the proliferation and metastasis of BC cells by regulating the expression of p21-activated protein kinase 2 (PAK2) gene. PATIENTS AND METHODS: A total of 50 cases of cancer tissue specimens and corresponding para-carcinoma normal tissue specimens were collected from the breast surgery department of our hospital from July 2016 to December 2017. BC MCF-7 cell line and normal breast epithelial MCF-10A cells were cultured. MiR-NC (negative control), LV-p21-activated protein kinase 2 (PAK2) and/or miR-216a-5p mimics were synthesized and transfected. The protein and mRNA expression level in BC tissues and cells were detected by Western blot and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) assay, respectively. Additionally, the Luciferase Reporter Assays, cell proliferation detection, clone formation assays and transwell migration and invasion assay were performed to determine the functional alteration of BC cells, respectively. RESULTS: The results of qRT-PCR demonstrated that miR-216a-5p was decreased in both BC tissues and cells compared with that in normal controls. Online target gene prediction software and Dual-Luciferase reporter assay were used for target identification, and PAK2 was identified as a functional target of miR-216a-5p in BC cells. The results were further clarified with the Western blot (WB) experiment. In vitro, cell functions were detected by Cell Counting Kit-8 (CCK-8), crystal violet staining and transwell experiment, respectively. The results indicated that decreased expression of PAK2 resulting from the up-regulation of miR-216a-5p could restrain the proliferation, clone formation, invasion and migration abilities of BC cells. CONCLUSIONS: We showed that miR-216a-5p played a role as antioncogene in BC, which provides a new therapeutic target for the treatment of BC.


Subject(s)
Breast Neoplasms/genetics , MicroRNAs/genetics , Up-Regulation , p21-Activated Kinases/genetics , p21-Activated Kinases/metabolism , 3' Untranslated Regions , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Movement , Cell Proliferation , Female , Gene Expression Regulation, Neoplastic , Humans , MCF-7 Cells
7.
Nat Mater ; 18(1): 76-81, 2019 01.
Article in English | MEDLINE | ID: mdl-30478453

ABSTRACT

The ability to tune ionic permeation across nanoscale pores profoundly impacts diverse fields from nanofluidic computing to drug delivery. Here, we take advantage of complex formation between crown ethers and dissolved metal ions to demonstrate graphene-based ion channels highly sensitive to externally applied lattice strain. We perform extensive room-temperature molecular dynamics simulations of the effects of tensile lattice strain on ion permeation across graphene-embedded crown ether pores. Our findings suggest the first instance of solid-state ion channels with an exponential permeation sensitivity to strain, yielding an order of magnitude ion current increase for 2% of isotropic lattice strain. Significant permeation tuning is also shown to be achievable with anisotropic strains. Finally, we demonstrate strain-controllable ion sieving in salt mixtures. The observed high mechanosensitivity is shown to arise from strain-induced control over the competition between ion-crown and ion-solvent interactions, mediated by the atomic thinness of graphene.

8.
Zhonghua Yan Ke Za Zhi ; 54(7): 520-525, 2018 Jul 11.
Article in Chinese | MEDLINE | ID: mdl-29996614

ABSTRACT

Objective: To investigate the changing trends of topical anti-glaucoma medications in the outpatient of the Eye Hospital of Wenzhou Medical University over the decade 2005-2014. Methods: Retrospective case series study. The medications data of glaucoma outpatients in the Eye Hospital of Wenzhou Medical University were collected for the period of January 1(st) 2005 to December 31(st) 2014. SPSS 20.0 statistical software was used, mainly for statistical description of the data. The main outcome measures were the proportions of the prescriptions of different medications, and the proportions of the monotherapy and combination therapies. Results: During the 10 years, the number of glaucoma outpatients increased year by year, from 994 in 2005 to 3 266 in 2014, the gender ration was close to 1∶1, and the age were (57±18) years. The proportion of ß-blockers decreased from 56.7% (750/1 323) in 2005 to 33.1% (2 120/6 407) in 2014. The proportion of cholinergic agents decreased from 17.2% (227/1 323) in 2005 to 10.3% (663/6 407) in 2014. While the proportion of prostaglandins increased from 13.3% (176/1 323) in 2005 to 36.8% (1 916/5 209) in 2011, which was close to the 37.9% (1 972/5 209) of ß-blockers in 2011. In 2012, the prostaglandins proportion increased to 41.9% (2 435/5 810) exceeding the 37.2% (2 161/5 810) of ß-blockers, and became the most prescribed medication. The proportion of prostaglandins continued to increase to 46.9% (3 008/6 407) in 2014. The proportion of α(2)-agonists increased from 17.0% (225/1 323) in 2005 to 22.8% (1 460/6 407) in 2014. The proportion of carbonic anhydrase inhibitors increased from 9.6% (127/1 323) in 2005 to 24.1% (1 546/6 407) in 2014.The proportion of monotherapy decreased from 78.0% (1 032/1 323) in 2005 to 58.6% (3 757/6 407) in 2014. The proportion of two drugs combination increased from 20.0% (264/1 323) in 2005 to 26.7% (1 709/6 407) in 2014. The proportion of three drugs combination increased from 2.0% (26/1 323) in 2005 to 12.3% (788/6 407) in 2014. The proportion of four drugs combination increased from 0.1% (1/1 323) in 2005 to 2.3% (150/6 407) in 2014. Conclusions: The changes of the proportions of topical anti-glaucoma medications were remarkable from 2005 to 2014 in the outpatient of the Eye Hospital of Wenzhou Medical University. The ß-blockers and cholinergic agents were declining, while the prostaglandins, α(2)-agonists and carbonic anhydrase inhibitors were increasing, and the prostaglandins became the most prescribed medication since 2012. The proportion of combination therapy was increasing. (Chin J Ophthalmol, 2018, 54: 520-525).


Subject(s)
Glaucoma , Universities , Adrenergic beta-Antagonists/therapeutic use , Antihypertensive Agents/therapeutic use , Carbonic Anhydrase Inhibitors/therapeutic use , Glaucoma/drug therapy , Humans , Prostaglandins, Synthetic , Retrospective Studies
9.
Zhonghua Yan Ke Za Zhi ; 54(3): 184-188, 2018 Mar 11.
Article in Chinese | MEDLINE | ID: mdl-29518876

ABSTRACT

Objective: To investigate the patterns of surgical treatment for patients with glaucoma in the Eye Hospital of Wenzhou Medical University from 2005 to 2014. Methods: Retrospective case series about 6 781 glaucoma patients (7 751 eyes) who received surgical treatment from January 1, 2005 to December 31, 2014 in the Eye Hospital of Wenzhou Medical University. Among them, 2 869 were males and 3 912 were females, aged (62±14) years. The data of patients' demographic information, diagnosis and surgical procedures [trabeculectomy, aqueous shunts of ExPRESS and Ahmed for extraocular reservoir, cataract extraction with intraocular lens (IOL) implantation, and combined operations for glaucoma and cataract] were collected and the patterns of surgical treatment were evaluated. SPSS 21.0 statistical software was used, mainly for statistical description of the data. Results: The ratio of trabeculectomies increased between 2005 and 2009, from 48.2% (95/197) to 57.7% (488/846), but decreased to 21.1% (220/1 041) in 2014. The ratio of aqueous shunts of ExPRESS and Ahmed increased to 6.1% (63/1 041) and 7.6% (79/1 041) from 2005 to 2014, respectively. The ratio of cataract extraction with IOL implantation increased to 28.4% (294/1 036) in 2012, but decreased to 21.6% (225/1 041) in 2014. The ratio of combined operations for glaucoma and cataract decreased to 6.6% (47/717) from 2005 to 2010, and increased to 36.6% (381/1 041) in 2014. Over the decade, the ratio of cataract extraction with goniosynechialysis increased from 2.4% (15/623) to 17.7% (184/1 041). The rate of iridotectomy decreased to 0.2% (2/1041) in 2014. Conclusions: Trabeculectomy, cataract surgery and combined surgery for glaucoma with cataract were still the mainstream of glaucoma surgery in the Eye Hospital of Wenzhou Medical University from 2005 to 2014. And the ratio of cataract extraction with IOL implantation, aqueous shunts of ExPRESS and Ahmed, and combined operation for glaucoma and cataract rapidly increased, with cataract extraction with goniosynechialysis increasing most rapidly and becoming the mainstream procedure of treatment for glaucoma and cataract. Inversely, the rate of trabeculectomies and iridotectomies decreased dramatically over this period.(Chin J Ophthalmol, 2018, 54: 184-188).


Subject(s)
Cataract Extraction , Cataract , Glaucoma , Trabeculectomy , Aged , Female , Glaucoma/surgery , Humans , Intraocular Pressure , Male , Middle Aged , Retrospective Studies , Treatment Outcome , Universities
10.
Proc Natl Acad Sci U S A ; 114(16): 4087-4092, 2017 04 18.
Article in English | MEDLINE | ID: mdl-28377516

ABSTRACT

We discovered unique Anderson localization behaviors of pseudospin systems in a 1D disordered potential. For a pseudospin-1 system, due to the absence of backscattering under normal incidence and the presence of a conical band structure, the wave localization behaviors are entirely different from those of conventional disordered systems. We show that there exists a critical strength of random potential ([Formula: see text]), which is equal to the incident energy ([Formula: see text]), below which the localization length [Formula: see text] decreases with the random strength [Formula: see text] for a fixed incident angle [Formula: see text] But the localization length drops abruptly to a minimum at [Formula: see text] and rises immediately afterward. The incident angle dependence of the localization length has different asymptotic behaviors in the two regions of random strength, with [Formula: see text] when [Formula: see text] and [Formula: see text] when [Formula: see text] The existence of a sharp transition at [Formula: see text] is due to the emergence of evanescent waves in the systems when [Formula: see text] Such localization behavior is unique to pseudospin-1 systems. For pseudospin-1/2 systems, there is also a minimum localization length as randomness increases, but the transition from decreasing to increasing localization length at the minimum is smooth rather than abrupt. In both decreasing and increasing regions, the [Formula: see text] dependence of the localization length has the same asymptotic behavior [Formula: see text].

11.
Zhonghua Xin Xue Guan Bing Za Zhi ; 45(3): 235-242, 2017 Mar 24.
Article in Chinese | MEDLINE | ID: mdl-28316181

ABSTRACT

Objective: To analyze the association between food intake and the serum total cholesterol(TC) level in adult Chinese population. Methods: This study included apparent healthy residents aged between 20 and 70 years who participated in the eighth round of China Health and Nutrition Study (CHNS) in 9 regions of China including Liaoning, Helongjiang, Shandong, Jiangsu, Henan, Hunan, Hubei, Guizhou provinces and Guangxi Zhuang Autonomous Region in 2009. The association between the serum TC level and the diet and other related factors were analyzed. Results: (1) Linear trend test showed that age, body mass index, waist circumference, systolic and diastolic blood pressure were positively related with serum TC level in 20-45 and 46-70 years old male and female (all P<0.01), while physical activity level was negatively related with serum TC level in 20-45 and 46-70 years old male and 46-70 years old female (all P<0.01). (2) Multivariate linear regression analysis showed that livestock meat intake was positively related with serum TC level in following populations: 20-45 years old male, ß=0.133, P<0.001; 46-70 years old male, ß=0.102, P=0.001; 20-45 years old male, ß=0.065, P=0.041; years old female, ß=0.059, P=0.045. Vegetable oil intake was negatively related with serum TC level in 20-45 years old male (ß=-0.071, P=0.021). Saturated fat intake was positively related with serum TC level in 46-70 years old female (ß=0.084, P=0.019). Total dietary cholesterol intake was positively related with serum TC level in male (20-45 years old, ß=0.067, P=0.021; 46-70 years old, ß=0.070, P=0.012), but not in female (20-45 years old, ß=0.007, P=0.809; 46-70 years old, ß=0.038, P=0.144). Cholesterol intake from livestock meat was positively related with serum TC level in male (20-45 years old, ß=0.156, P<0.001; 46-70 years old, ß=0.099, P=0.001), and positively related with serum TC level in 46-70 years old female (ß=0.063, P=0.028). Cholesterol intake from egg was positively related with serum TC level in 46-70 years old male (ß=0.056, P=0.032). Conclusions: Age, body mass index, waist circumference, blood pressure, blood pressure, and physical activity level are related with serum TC level. Cholesterol intake from livestock meat was the main food source that related with serum TC level, and the serum TC increases at a relatively small level after intake of total dietary cholesterol.


Subject(s)
Blood Pressure , Cholesterol , Diet , Aged , China , Cholesterol, Dietary , Exercise , Female , Humans , Male , Middle Aged , Waist Circumference
12.
Eur J Clin Microbiol Infect Dis ; 35(3): 353-61, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26796551

ABSTRACT

To detect Salmonella more efficiently and isolate strains more easily, a novel and simple detection method that uses an enrichment assay and two chromogenic reactions on a chromatography membrane was developed. Grade 3 chromatography paper is used as functionalized solid phase support (SPS), which contains specially optimized medium. One reaction for screening is based on the sulfate-reducing capacity of Salmonella. Hydrogen sulfide (H2S) generated by Salmonella reacts with ammonium ferric citrate to produce black colored ferrous sulfide. Another reaction is based on Salmonella C8 esterase that is unique for Enterobacteriaceae except Serratia and interacts with 4-methylumbelliferyl caprylate (MUCAP) to produce fluorescent umbelliferone, which is visible under ultraviolet light. A very low detection limit (10(1) CFU ml(-1)) for Salmonella was achieved on the background of 10(5) CFU ml(-1) Escherichia coli. More importantly, testing with more than 1,000 anal samples indicated that our method has a high positive detection rate and is relatively low cost, compared with the traditional culture-based method. It took only 1 day for the preliminary screening and 2 days to efficiently isolate the Salmonella cells, indicating that the new assay is specific, rapid, and simple for Salmonella detection. In contrast to the traditional culture-based method, this method can be easily used to screen and isolate targeted strains with the naked eye. The results of quantitative and comparative experiments showed that the visual detection technique is an efficient alternative method for the screening of Salmonella spp. in many applications of large-sized samples related to public health surveillance.


Subject(s)
Bacteriological Techniques , Chromatography, Paper/methods , Salmonella/isolation & purification , Humans , Hydrogen Sulfide/metabolism , Hymecromone/analogs & derivatives , Hymecromone/chemistry , Salmonella/classification , Salmonella/metabolism , Salmonella Infections/diagnosis , Salmonella Infections/microbiology , Sensitivity and Specificity
14.
Carbohydr Polym ; 116: 189-99, 2015 Feb 13.
Article in English | MEDLINE | ID: mdl-25458289

ABSTRACT

Capillary flow-based approach such as microfluidic devices offer a number of advantages over conventional flow control technology because they ensure highly versatile geometry and can be used to produce monodisperse spherical and non-spherical polymeric microparticles. Based on the principle of a flow-focusing device to emulsify the coflow of aqueous solutions in an organic phase, we were able to produce the following innovative polysaccharide hydrogel microparticles: - Janus hydrogel microparticles made of pectin­pectin (homo Janus) and pectin­alginate (hetero Janus) were produced. The efficiency of separation of the two hemispheres was investigated by confocal scanning laser microscopy (CSLM) of previously labelled biopolymers. The Janus structure was confirmed by subjecting each microparticle hemisphere to specific enzymatic degradation. As a proof of concept, free BSA or BSA grafted with dextran, were encapsulated in each hemisphere of the hetero Janus hydrogel microparticles. While BSA, free or grafted with dextran, was always confined in the alginate hemisphere, a fraction of BSA diffused from the pectin to the alginate hemisphere. Methoxy groups along the pectin chain will be responsible of the decrease of the number of attractive electrostatic interactions occurring between amino groups of BSA and carboxylic groups of pectin. - Pectin hydrogel microparticles of complex shapes were successfully produced by combining on-chip the phenomenon of gelation and water diffusion induced self-assembly, using dimethyl carbonate as continuous phase, or by deformation of the pre-gelled droplets off-chip at a fluid­fluid interface. Sphere, oblate ellipsoid, torus or mushroom-type morphologies were thus obtained. Moreover, it was established that after crossing the interface during their collect, mushroom-type microparticles did not migrate in the calcium or DMC phase but stayed at the liquid­liquid interface. These new and original hydrogel microparticles will open up opportunities for studying relationships between combined enzymatic hydrolysis and active release for Janus particles and relationships between shape and swelling behaviour for anisotropic pectin microparticles.


Subject(s)
Alginates/chemistry , Hydrogels/chemistry , Pectins/chemistry , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Microfluidics , Serum Albumin, Bovine/chemistry
15.
Clin Exp Dermatol ; 40(1): 63-70, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25283714

ABSTRACT

BACKGROUND: Photodynamic therapy (PDT), a therapeutic approach employing a photosensitizer and a specific wavelength of light, is an emerging option for treating neoplastic and nonneoplastic diseases. Keloids are fibroproliferative dermal lesions characterized by the proliferation of fibroblasts. Recently, PDT has been demonstrated as a potential treatment for keloids. AIM: To investigate the effects of our newly synthesized photosensitizer 2-(4-aminophenyl)-7-methoxybenzothiazole (6d) plus ultraviolet (UV)A irradiation (6d-UVA) on proliferation and apoptosis in keloid fibroblasts (KFs). METHODS: Fibroblasts cultured from normal skin and keloids were treated with 6d-UVA. Relevant assays including 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-bromo-2'-deoxyuridine incorporation assay, immunofluorescence assay and flow cytometry analysis were performed. RESULTS: The combination of 6d (2.0 or 5.0 µmol/L) and UVA 0.5 J/cm(2) significantly decreased the viability and proliferation of KFs but not normal fibroblasts (NFs). Cell cycle analyses showed significant G0/G1 arrest and increased sub-G1 distribution in NFs induced by UVA-activated 6d at 5.0 µmol/L (hereafter referred to as 6d-UVA). This treatment also significantly induced generation of intracellular reactive oxygen species (ROS), loss of mitochondrial membrane potential (ΔΨm), and increased expression of active caspase-3. Pretreatment with N-acetyl-L-cysteine (aROS scavenger) reversed the increased active caspase-3 expression induced by 6d-UVA, indicating the involvement of ROS in 6d-UVA-induced apoptosis. CONCLUSIONS: This study indicates that 6d-UVA treatment exerts antiproliferative and pro-apoptotic effects in KFs. We propose that 6d-UVA could be a potentially usefull ancillary method for keloid treatment.


Subject(s)
Aniline Compounds/therapeutic use , Benzothiazoles/therapeutic use , Fibroblasts/drug effects , Keloid/drug therapy , Photochemotherapy/methods , Photosensitizing Agents/pharmacology , Apoptosis/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Fibroblasts/radiation effects , Humans
16.
J Phys Condens Matter ; 26(43): 435601, 2014 Oct 29.
Article in English | MEDLINE | ID: mdl-25299070

ABSTRACT

We present the optical conductivity spectra for the newly discovered cubic perovskite structure BaOsO3 at various temperatures. The compound exhibits metallic behaviour above 50 K, but becomes non-metallic below 50 K. However, below 550 cm(-1), neither the typical Drude response nor an energy gap is observed in optical conductivity spectra from 300 K to 10 K. A broad peak centred at about 550 cm(-1) is observed in the real part of optical conductivity σ1(ω). The structure could be well reproduced by the localization modified Drude model. The life time of the carrier, deduced from σ1(ω) in terms of the localization modified Drude model, decreases with T varying from 300 K to 100 K, then increases slightly at 10 K. The study indicates that the compound is at the boundary of metal-insulator transition.

17.
J Eur Acad Dermatol Venereol ; 28(2): 204-15, 2014 Feb.
Article in English | MEDLINE | ID: mdl-23301526

ABSTRACT

BACKGROUND: Atopic dermatitis (AD) is a commonly encountered inflammatory skin disease. Although acute lesions of acute AD are characterized by intense inflammation, the hallmarks of chronic AD lesions include lichenified fibrosis and thickening of the upper dermis. The increased expression of transforming growth factor beta 1 (TGF-ß1), a well-known fibrogenic cytokine, is observed in chronic AD lesions. Tacrolimus (FK506) ointment has been reported to be effective for treating AD as well as some TGF-ß1-induced fibrotic diseases. OBJECTIVES: To evaluate the effect of tacrolimus on TGF-ß1-stimulated cultured normal human dermal fibroblasts and explore the potential signalling pathways involved. METHODS: Fibroblasts cultured from healthy adult human foreskins were treated with TGF-ß1 with or without tacrolimus. The impact on cell viability and proliferation were assessed by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay and BrdU incorporation assay respectively. Reverse transcription-polymerase chain reaction (RT-PCR), quantitative real-time PCR, enzyme-linked immunosorbent assay (ELISA) and western blotting were performed to evaluate the relevant expressions of mRNA or proteins in fibroblasts. RESULTS: Our results revealed that the increased expressions of transforming growth factor-ß receptor I (TGF-ßRI) and TGF-ßRII in TGF-ß1-treated fibroblasts were suppressed by tacrolimus treatment. In addition, tacrolimus significantly inhibited fibroblast proliferation enhanced by TGF-ß1. TGF-ß1 increased type I collagen production, and this enhancing effect was suppressed by tacrolimus. The down-regulation of MMP-1 and up-regulation of TIMP-1 induced by TGF-ß1 were reversed by tacrolimus. The increase in phosphorylated p38 mitogen-activated protein kinase (p38MAPK) expression stimulated by TGF-ß1 was down-regulated by tacrolimus. Moreover, the fibroblasts treated with p38MAPK inhibitor significantly reduced type I collagen expression induced by TGF-ß1. CONCLUSIONS: The present results demonstrated that tacrolimus significantly inhibited physiological functions of fibroblasts enhanced by TGF-ß1 in vitro. Clinically, we propose that topical tacrolimus may not only reduce AD recurrence but also ameliorate dermal fibrosis often seen in chronic AD lesions.


Subject(s)
Collagen Type I/biosynthesis , Immunosuppressive Agents/pharmacology , MAP Kinase Signaling System/drug effects , Tacrolimus/pharmacology , Transforming Growth Factor beta1/pharmacology , p38 Mitogen-Activated Protein Kinases/metabolism , Cell Proliferation/drug effects , Cell Survival/drug effects , Cells, Cultured , Chronic Disease , Collagen Type I/genetics , Dermatitis, Atopic/drug therapy , Down-Regulation/drug effects , Fibroblasts , Humans , Immunosuppressive Agents/therapeutic use , Matrix Metalloproteinase 1/genetics , Matrix Metalloproteinase 1/metabolism , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , RNA, Messenger/metabolism , Receptor, Transforming Growth Factor-beta Type I , Receptor, Transforming Growth Factor-beta Type II , Receptors, Transforming Growth Factor beta/genetics , Receptors, Transforming Growth Factor beta/metabolism , Tacrolimus/therapeutic use , Tissue Inhibitor of Metalloproteinase-1/genetics , Tissue Inhibitor of Metalloproteinase-1/metabolism , Up-Regulation/drug effects
18.
Sci Rep ; 3: 1153, 2013.
Article in English | MEDLINE | ID: mdl-23362455

ABSTRACT

Ir(1-x)Pt(x)Te2 is an interesting system showing competing phenomenon between structural instability and superconductivity. Due to the large atomic numbers of Ir and Te, the spin-orbital coupling is expected to be strong in the system which may lead to nonconventional superconductivity. We grew single crystal samples of this system and investigated their electronic properties. In particular, we performed optical spectroscopic measurements, in combination with density function calculations, on the undoped compound IrTe2 in an effort to elucidate the origin of the structural phase transition at 280 K. The measurement revealed a dramatic reconstruction of band structure and a significant reduction of conducting carriers below the phase transition. We elaborate that the transition is not driven by the density wave type instability but caused by the crystal field effect which further splits/separates the energy levels of Te (p(x), p(y)) and Te p(z) bands.


Subject(s)
Iridium/chemistry , Models, Chemical , Models, Molecular , Tellurium/chemistry , Computer Simulation , Molecular Conformation , Phase Transition , Spectrum Analysis
19.
J Perinatol ; 33(3): 218-21, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22766743

ABSTRACT

OBJECTIVE: Sildenafil is occasionally used as rescue treatment for preterm infants with severe bronchopulmonary dysplasia and pulmonary arterial hypertension. In adults, sildenafil treatment has been associated with several ophthalmological adverse effects, including nonarteritic ischaemic optic neuropathy. We reviewed the effect of sildenafil on retinopathy of prematurity (ROP) in very preterm infants. STUDY DESIGN: Retrospective case-control study. Infants born <30 weeks gestation who had received sildenafil during their hospitalisation were included. A control group matched for gestation, birth weight, gender, and place of birth was identified from the departmental database. For every sildenafil case, three matched controls were studied. Baseline data, sildenafil therapy data, results of eye examinations and respiratory data were analysed. RESULT: 17 infants received sildenafil between 2004 and 2010. The median duration of sildenafil treatment was 52 days. Baseline characteristics were similar between groups. The odds ratio for an increase in ROP stage in the group treated with sildenafil was 1.35 (95% confidence interval 0.39-4.62, P-value 0.63). One infant in each group required laser treatment. CONCLUSION: Sildenafil treatment did not affect ROP progression or increase the need for laser treatment in this cohort.


Subject(s)
Bronchopulmonary Dysplasia/drug therapy , Phosphodiesterase 5 Inhibitors/therapeutic use , Piperazines/therapeutic use , Retinopathy of Prematurity/chemically induced , Sulfones/therapeutic use , Case-Control Studies , Disease Progression , Humans , Infant, Newborn , Infant, Premature , Phosphodiesterase 5 Inhibitors/adverse effects , Piperazines/adverse effects , Purines/adverse effects , Purines/therapeutic use , Sildenafil Citrate , Sulfones/adverse effects
20.
Br J Dermatol ; 167(3): 532-41, 2012 Sep.
Article in English | MEDLINE | ID: mdl-22540338

ABSTRACT

BACKGROUND: Keloid is a unique proliferative disorder of fibroblasts resulting from derailment of the typical wound healing process. Due to lack of animal models for therapeutic testing, treatment of keloids remains a clinical challenge. Transforming growth factor (TGF)-ß1-related signalling plays a key role in keloid formation. As tacrolimus (FK506) has been reported to inhibit the effects of TGF-ß1 on cultured fibroblasts, we hypothesized that FK506 may be useful in treating keloids. OBJECTIVES: To explore the effects of FK506 on TGF-ß1-stimulated keloid fibroblasts (KFs) in terms of proliferation, migration and collagen production and to investigate the regulatory pathways involved. METHODS: Fibroblasts derived from keloids were treated with TGF-ß1 with or without FK506. Relevant assays including 5-bromo-2'-deoxyuridine incorporation assay, in vitro scratch assay, reverse transcription-polymerase chain reaction (PCR), quantitative PCR and Western blotting were performed. RESULTS: The proliferation and migration of KFs were significantly higher than those of normal fibroblasts. FK506 markedly inhibited KF proliferation, migration and collagen production enhanced by TGF-ß1. The increase in TGF-ß receptor I and II expression in TGF-ß1-treated KFs was suppressed by FK506 treatment. TGF-ß1 increased the phosphorylation of Smad2/3 and Smad4 in KFs, and this enhancing effect was abrogated by FK506. In addition, FK506 significantly increased the expression of Smad7 which was suppressed by TGF-ß1 treatment. CONCLUSIONS: Our results demonstrate that FK506 effectively blocks the TGF-ß/Smad signalling pathway in KFs by downregulation of TGF-ß receptors and suggest that FK506 may be included in the armamentarium for treating keloids.


Subject(s)
Collagen/biosynthesis , Fibroblasts/drug effects , Immunosuppressive Agents/pharmacology , Keloid/metabolism , Smad Proteins/metabolism , Tacrolimus/pharmacology , Transforming Growth Factor beta/antagonists & inhibitors , Adult , Cell Movement/drug effects , Cell Movement/physiology , Cell Proliferation/drug effects , Cells, Cultured , Down-Regulation , Female , Fibroblasts/physiology , Humans , Keloid/pathology , Receptors, Transforming Growth Factor beta/drug effects , Signal Transduction/physiology
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