Search

Bismuth-Yttrium Oxide Bi3YO6 (BYO) is well-known among researchers for its potential applications in different fields but its use as an electrode for asymmetric supercapacitor (ASC) has not yet been discussed and uncovered. As high energy and power densities could be well achieved with the aid of optimum potential. In the current scenario, BYO is used as an electrode material for ASCs for the first time. The material is prepared by a solid-state reaction method and its structural, morphological, and electrochemical properties have been explored by using different characterization tools. Structural analysis declared the flourite based structure of BYO having a cubic phase without any visible impurity. In a morphological analysis, a mesoporous thin film with a high surface area (~ 36.6 m2 g−1) with a narrow pore width of (~ 5–18 nm) has been observed. The as-prepared BYO employed as an electrode material for SCs delivers a high specific capacitance of (388 F g−1 at 100 m Vs−1 in the three-electrode system) with excellent cycling stability (5% loss after 6000 cycles). Essentially, an ASC is assembled using BYO and rGO as a positive and negative electrodes operating in a stable and wide potential window up to 2.2 V. Moreover, a high energy density of 11 Wh kg−1 along with a power density of 648 W kg−1 is obtained and maintained a high power density of 888 W kg−1 with the downfall of energy density to 3.7 Wh kg−1. The results prove electrode material as an alternative promising candidate for ASCs.

Ferrocene-decorated cellulosic materials are usually obtained via a couple of synthetic procedures, which might possibly affect their degree of substitution. In this work, two ferrocene-decorated cellulose esters, connected either by monocarboxylate or by dicarboxylate linkers, have been prepared via one-step reactions by means of esterifying microcrystalline cellulose (MCC) with ferrocenemonocarboxylic acid and 1,1’-ferrocenedicarboxylic acid (FcDA), respectively. Successful surface modification has been confirmed by elemental analysis, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetric measurements. Large retention of the crystalline morphology can be revealed by powder X-ray diffraction, confirming its surface decoration as well. Cyclic voltammetry results of both esters have demonstrated that the winding of the cellulose chains in MCC-FcDA caused by its cross-linking structure might have unfavorable effect for electron transfer, resulting in weaker reversibility of its redox process. Therefore, exploration of a suitable linker might be of great importance to achieve ideal electrochemical properties. Two ferrocene-decorated cellulose esters connected either by mono or by dicarboxylate linkers have been synthesized via one-step reactions, exhibiting the more electrochemical reversibility of the monocarboxylate-linked ester.

We explored the effects of compound 33, a synthetic chalcone derivative with antioxidant activity, on lipopolysaccharide (LPS)-induced acute lung injury (ALI). Compound 33, dexamethasone or vehicle was administered intragastrically to mice 6 h before intratracheal instillation of LPS. After 24 h, the effects of compound 33 on alveolar structural damage were evaluated by assessing lung morphology and the wet/dry weight ratio. Protein and proinflammatory cytokine levels and superoxide dismutase activity were also examined in the cell free supernatant of bronchoalveolar lavage fluid. Additionally, we investigated the anti-inflammatory and antioxidant activity of compound 33 in vitro and its effects on the MAPK/NF-κB and Nrf2/HO-1 pathways. Pretreatment with compound 33 prevented LPS-induced structural damage, tissue edema, protein exudation, and overproduction of proinflammatory mediators. The effects of compound 33 were similar to or greater in magnitude than those of the positive control, dexamethasone. Moreover, compound 33 exerted anti-inflammatory and antioxidant effects in vitro by inhibiting the MAPK/NF-κB pathway and activating the Nrf2/HO-1 pathway. Compound 33 may therefore be a promising candidate treatment for ALI.

Background Chalcone, a natural product, has a wide range of biological activities. L2H17, a chalcone derivative, was synthesized and screened in our previous study and exhibited excellent anti-inflammatory property in vitro. This study investigated the therapeutic potential of L2H17 on lipopolysaccharide (LPS)-induced acute lung injury (ALI) and the role of heme oxygenase-1 (HO-1). Materials and methods An ALI animal model was induced by LPS (10 mg/kg) intratracheal instillation. The effect of L2H17 on LPS-induced structural damage was determined using hematoxylin and eosin (HE) staining, and tissue edema extent was examined. Bronchoalveolar lavage fluid (BALF) was harvested to assess the levels of related cytokines by enzyme-linked immunosorbent assay (ELISA), and superoxide dismutase (SOD) activity was also assessed. HO-1 expression was determined using immunohistochemistry and western blotting. The effects of L2H17 on LPS stimulation in RAW 264.7 and the involvement of the HO-1 pathway were investigated. Results L2H17 alleviated the histopathological manifestations and tissue edema. Moreover, L2H17 decreased the production of pro-inflammatory factors in BALF and increased SOD activity. In vitro, L2H17 significantly reduced pro-inflammatory cytokine production. Additionally, L2H17 improved the expression of HO-1 in LPS-treated lung tissue and RAW 264.7. We also found that the inhibitory effect of L2H17 on the inflammatory responses was attenuated by an inhibitor of HO-1 activity, Tin protoporphyrin IX (SnPP). Conclusion Our data confirmed that L2H17 can exert protective effect on ALI in vitro and in vivo by inhibiting inflammatory responses and modulating the HO-1 pathway.

For the past few years, two-dimensional materials have attracted widespread attention owing to their special properties and potential applications. It is well-known that graphene, transition metal disulfide compounds (TMDC), carbon nitride, transition metal carbonitrides (Mxenes), silene and hexagonal boron nitride are typical two-dimensional materials. Compared with these traditional two-dimensional materials, two-dimensional MOF is favored by numerous researchers because of its unique structure. Based on the unique metal ion and organic ligand coordination of MOF and two-dimensional layered structure, the applications of two-dimensional MOF were getting serious, including catalysis, supercapacitor, gas adsorption/separation, sensors and so on. This review presents a relatively comprehensive summary of the design & synthesis and applications of two-dimensional MOF over the past few years. Furthermore, the opportunities and challenges have been discussed to supply a promising prospect to this field.

Random skin flaps are often used in plastic surgery, but the complications of marginal flap ischemia and necrosis often limit their wider clinical application. Apigenin (Api) is a flavonoid found in various fruits and vegetables. Api has been shown to promote angiogenesis, as well as reduce oxidative stress, membrane damage, and inflammation. In this study, we assessed the effects of Api treatment on random skin flap survival. Dorsal McFarlane skin flaps were transplanted into rats, which were randomly divided into three groups: control (normal saline), low-dose Api (20 mg/kg), and high-dose Api (50 mg/kg). Seven days after the surgery, the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) were measured. Histological analyses were performed to determine flap survival and tissue edema. H&E staining was performed to assess the histopathological changes in skin flaps, and the levels of microvascular density (MVD) were determined. Laser doppler flowmetry was used to assess microcirculation blood flow. Flap angiography was performed by injection of lead oxide/gelatin. The expression levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interlukin-1β (IL-lβ) were evaluated by immunohistochemistry. Rats in the high-dose Api group exhibited higher average flap survival area, microcirculatory flow, increased SOD activity, and higher VEGF expression levels compared with the other two groups. Furthermore, the levels of MDA and pro-inflammatory cytokines were significantly decreased in rats treated with high-dose Api. Our findings suggest the potential usefulness of Api in preventing skin flap tissue necrosis.

Objective: To determine the effect of Shu Xue Tong treatment on random skin flap survival. Methods: Twenty-four male Sprague-Dawley (SD) rats were administered Shu Xue Tong or normal saline. On postoperative day 7, flap survival area, flap angiogenesis angiography, blood flow and vascular endothelial growth factor (VEGF), Notch1, and Delta-like ligand 4 (Dll4) expression were assessed. Results: The mean flap survival area, blood vessel regeneration, microcirculatory flow, and expression of VEGF were enhanced with Shu Xue Tong treatment relative to the control. However, in Shu Xue Tong-treated rat flap, Notch1 and Dll4 levels were significantly reduced. Conclusions: These results demonstrate the beneficial action of Shu Xue Tong on random skin flap survival and suggest that its mechanism of action involves the promotion of angiogenesis via the VEGF-Notch1/Dll4 signaling pathway.

Incorporating security labels with physical unclonable functions (PUFs) into products is considered as the most effective anti-counterfeiting measure. Here we reported a PUF-based security label composed of random colorful patterns. The security label was fabricated through self-assembly of coordination polymers – a cupric bromide complex of pyrazine 1,4-dioxide – on lithographically defined plasmonic surfaces. The coordination polymer exhibits excitation wavelength dependent fluorescence fingerprints, which enables encoding spectral information in the polymer. The fluorescence peaks of each spectrum can be easily converted to a unique anti-counterfeiting barcode. The developed security label also carries 2D graphical information, which can be visualized under bright-field, dark-field and fluorescence multifunctional microscopy. It is multicolored with high contrast under the bright/dark-field modes and single color under fluorescence mode. The multicolors originate from polymer-thickness dependent optical interference. The encryption with colors on a 50 μm square produces a minimum of 3739 PUF codes for the realized authentication system. Moreover, we developed a convenient and reliable authentication strategy based on the computer vision technique to verify the colorful PUF patterns with different definition, rotation angles, brightness, magnification and a mixture of these factors. A high correct validation rate of 100% is achieved using a match threshold of 0.3.

Mesenchymal stromal cells (MSCs) have been extensively investigated as a potential antiinflammatory treatment in many inflammatory‐related diseases; however, it remains unclear whether MSCs could be used to treat acute allergic rhinitis. A rat model of allergic rhinitis was treated with MSCs. The effect of MSCs on the inflammation of allergic rhinitis was evaluated by sneezing, nose rubbing, the pathology of the nasal mucosa, and the expression of interleukin 4, tumour necrosis factor alpha, and immunoglobulin E in the serum of rats. Also, the population of MSCs isolated from umbilical cords of humans was evaluated to determine if they could inhibit the symptoms and inflammation of acute allergic rhinitis in a rat model. We observed that this population of cells inhibited sneezing, nose rubbing, and changes in the pathology of the nasal mucosa. Intriguingly, we observed that MSCs reduced the expression of interleukin 4, tumour necrosis factor alpha, and immunoglobulin E in the serum. Furthermore, MSCs reduced the expression of histamine and the recruitment of macrophages in the nasal mucosa of allergic rhinitis rats. We reasoned that the effect of MSCs on allergic rhinitis might be through its regulation of the secretion of related cytokines from macrophages during the process of acute allergic rhinitis. This work suggested that MSCs from the umbilical cords of humans could be used as a positive clinical therapy for the human disease.

Our research group has previously synthesized various chalcone analogues. Of these analogues, compound 39 has been shown to exhibit potent antioxidative activities but its anti-inflammatory and anti-apoptosis effects remain unclear. Thus, the present study investigated the in vivo and in vitro effects and mechanisms of compound 39 in lipopolysaccharide (LPS)-induced acute lung injury (ALI). To induce ALI, the mice received LPS via a tracheal instillation 6 h after intragastric administration of compound 39 or vehicle. Histological changes, the lung wet/dry weight ratio, and the amounts of protein and inflammatory cells in the broncho-alveolar lavage (BAL) fluid were assessed after 24 h. Additionally, to determine its underlying mechanisms, Western blot and immunofluorescence analyses were used. Moreover, the in vitro effects of compound 39 were also investigated. In the in vivo experiment, compound 39 markedly alleviated histopathological alterations, lung edema, and protein leakage, and exhibited potent anti-inflammatory effects. In the in vitro experiments, compound 39 dose-dependently reduced the levels of pro-inflammatory cytokines and reactive oxygen species. The results suggested that the anti-inflammatory effects of compound 39 were due to suppression of the mitogen-activated protein kinase (MAPK)/nuclear factor κB (NF-κB) pathway. Compound 39 also enhanced the protein levels of Bcl-2 and reduced the protein levels of Bax and cleaved caspase-3. The present study confirmed the anti-inflammatory, oxy-radical prohibitive, and anti-apoptosis activities of compound 39 against LPS-induced tissue and cell damage, and revealed the mechanisms underlying those processes.

This study was performed to examine the protective effects of icariin (ICA) on ischemic random skin flaps. A rat random-pattern skin flap model was established, and animals in the low-dose and high-dose experimental groups were administered ICA intraperitoneally at doses of 40 and 80 mg/kg, respectively, once daily for 7 days after the initial surgery. Control rats received vehicle according to the same schedule. Survival rates were observed and recorded using transparent graph paper, and flaps were obtained and stained with hematoxylin and eosin (H&E). The malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the flap tissue were assessed. The blood flow volume was determined by the laser Doppler method, and tissue expression levels of vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), interleukin-1β, and phosphodiesterase 5 (PDE5) were scored immunohistochemically. The levels of proinflammatory cytokines, including tumor necrosis factor-α and IL-6, were determined by enzyme-linked immunosorbent assay. The main flap survival area was significantly larger in rats treated with ICA than in vehicle-treated controls. H&E staining showed an inhibitory effect of ICA on inflammation, especially at the high dose. In addition, ICA treatment was associated with decreases in the tissue MDA level, proinflammatory cytokine production, and the level of PDE5, but increases in SOD activity, blood flow volume, and the level of VEGF expression. The findings of the present study suggest that ICA is a potential therapeutic agent for random-pattern skin flap necrosis in the clinical setting.

Objective This study explored the effects of urinary kallidinogenase (UK) on ischemia and necrosis of random skin flaps in rats, and the mechanisms thereof. Methodology Ischemia and necrosis of random skin flaps were induced by constructing a modified McFarlane flap model on the dorsa of rats. UK (0.016 PNA/kg) or normal saline (10 ml/kg, control) was administered through the tail vein immediately after flap ischemia model construction and then daily for 7 days. After sacrifice, the flap tissue was harvested and stained with hematoxylin and eosin (H&E), and histopathological changes were observed. Lead oxide/gelatin angiography and laser Doppler imaging were performed to demonstrate angiogenesis and changes in blood flow. Immunohistochemical analysis of the H&E-stained slices was performed to detect the expression of vascular endothelial growth factor (VEGF), interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α). The TNF-α and IL-6 levels were also detected by enzyme-linked immunosorbent assays. The activity of superoxide dismutase (SOD) and the malondialdehyde (MDA) content were measured to represent the oxidative damage level. Results UK significantly alleviated ischemia and necrosis of random skin flaps, as evidenced by improved general results and histopathological manifestations, and markedly increased the mean survival area. UK prompted angiogenesis, increased blood flow and VEGF expression. The levels of TNF-α, IL-6, and IL-1β were declined. Furthermore, UK increased SOD activity and decreased MDA content, suggesting that it has the capacity to alleviate oxidative damage. Conclusion These findings suggest that UK sufficiently attenuated flap ischemia and increased the survival of random skin flaps in rats.

Nitrogen doping can effectively protect the pore structure of carbon materials and improve their electrochemical properties. In this work, shaddock peel-based activated carbon doped with nitrogen was obtained by a high temperature nitriding method using dopant urea. The activated carbon was characterized and tested by XRD, SEM, TEM, BET, XPS, etc. The results show that with the increase of nitrogen doping ratio, the specific surface area (SSA) of activated carbon first increases and then decreases. The SSA of activated carbon doped with triple urea is 2450.6 m2/g. The SSA increased by 26.7%. In the 6 M potassium hydroxide electrolyte, served as the electrode, the mass specific capacity of activated carbon doped with triple urea under the current density of 1A/g reaches 325 F/g and an outstanding cycling stability (292 F/g after 10,000 cycles).

Two Schiff base ligands (2a and 2b) and their zinc complexes (3a and 3b) have been designed and facilely synthesized through simple condensation reactions using compound 1 derived from natural dehydroabietic acid as the precursor. The larger dihedral angles of the ligands shown by the single crystal X-ray diffraction analysis indicate their stronger molecular motion, which is in consistence with their low fluorescence efficiency that is verified by the photophysical measurements. After coordination with zinc ions, the fluorescence intensity of the zinc complexes is larger, which might be explained by the structural rigidification via coordination, thereby reducing the energy loss from molecular motion. Furthermore, complex 3b exhibits a specific negative solvatochromic effect, and the absorption of its maximum wavelength shows a hypsochromic shift with increased polarity. Such solvatochromic phenomena can be explained by the synergy of intramolecular charge transfer and the proximity effect that may increase the energy difference between the ground state and the excited state in polar solvents. This work not only discusses their relationship between photophysical properties and structures, but also provides a new natural source for further research in fluorescent materials.

5-Fluorouracil (5FU) was successfully entrapped within poly(lactide-co-glycolide) (PLGA) and hydroyapatite (HA) composite microspheres using the emulsification/solvent extraction technique. The effects of HA to PLGA ratio, solvent ratio as well as polymer inherent viscosity (IV) on encapsulation efficiency were investigated. The degradation and drug release rates of the microspheres were studied for 5 weeks in vitro in phosphate buffered solution of pH 7.4 at 37 °C. The drug release profile followed a biphasic pattern with a small initial burst followed by a zero-order release for up to 35 days. The initial burst release decreased with increasing HA content. The potential of HA in limiting the initial burst release makes the incorporation of HA into PLGA microspheres advantageous since it reduces the risk of drug overdose from high initial bursts. The linear sustained drug release profile over the course of 5 weeks makes these 5-FU-loaded HA/PLGA composite microparticles a promising delivery system for the controlled release of chemotherapy drugs in the treatment of cancer.

Hemin, a heme oxygenase-1 (HO-1) inducer, was shown to exert numerous beneficial physiological functions in animals. Our previous study suggests that HO-1/carbon monoxide (CO) acts as a novel downstream signal system in the auxin-induced adventitious rooting. The objective of this study was to test whether nitric oxide (NO) is involved in hemin-induced cucumber adventitious rooting. Applications of hemin or CO aqueous solution to auxin-depleted cucumber explant induced up-regulation of cucumber HO-1 transcripts (CsHO1), NO production, and thereafter adventitious root formation, and some above responses were blocked by the combination treatment with two nitric oxide synthase (NOS)-like enzyme inhibitors N(G)-nitro-L-arginine methylester hydrochloride and N(G)-nitro-L-arginine, a HO-1 specific inhibitor zinc protoporphyrin IX, and a specific NO scavenger 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt. However, these blocking responses were not observed using tungstate, an inhibitor of nitrate reductase, another NO producing enzyme in plants. Furthermore, the guanylate cyclase inhibitors 1H-(1,2,4)-oxadiazole[4,3-a]quinoxalin-1-one and 6-anilino-5,8-quinolinedione reduced root development induced by hemin, whereas the cell-permeable cyclic guanosine monophosphate (cGMP) derivative 8-Br-cGMP reversed this effect. Together, our results indicated that at least in our experimental conditions, NO might operate downstream of hemin promoting adventitious root formation probably in a cGMP-dependent manner.

Our previous results showed that β-cyclodextrin–hemin complex (CDH) exhibited a vital protective role against cadmium-induced oxidative damage and toxicity in alfalfa seedling roots by the regulation of heme oxygenase-1 (HO-1) gene expression. In this report, we further test whether CDH exhibited the hormonal-like response. The application of CDH and an inducer of HO-1, hemin, were able to induce the up-regulation of cucumber HO-1 gene (CsHO1) expression and thereafter the promotion of adventitious rooting in cucumber explants. The effect is specific for HO-1 since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPP) blocked the above responses triggered by CDH, and the inhibitory effects were reversed further when 30 % saturation of CO aqueous solution was added together. Further, molecular evidence showed that CDH triggered the increases of the HO-1-mediated target genes responsible for adventitious rooting, including one DnaJ-like gene (CsDNAJ-1) and two calcium-dependent protein kinase (CDPK) genes (CsCDPK1 and CsCDPK5), and were inhibited by ZnPP and reversed by CO. The calcium (Ca2+) chelator ethylene glycol-bis (2-aminoethylether)-N,N,N′,N′-tetraacetic acid (EGTA) and the Ca2+ channel blocker lanthanum chloride (LaCl3) not only compromised the induction of adventitious rooting induced by CDH but also decreased the transcripts of above three target genes. However, the application of ascorbic acid (AsA), a well-known antioxidant in plants, failed to exhibit similar inducible effect on adventitious root formation. In short, above results illustrated that the response of CDH in the induction of cucumber adventitious rooting might be through HO-1-dependent mechanism and calcium signaling. Key message Physiological, pharmacological and molecular evidence showed that β-cyclodextrin–hemin complex (CDH) was able to induce cucumber adventitious rooting through heme oxygenase-1 (HO-1)-dependent mechanism and calcium signaling.

Results from our previous study suggested that haem oxygenase-1/carbon monoxide (HO-1/CO) acts as a downstream signal system in the auxin-induced pathway leading to cucumber (Cucumis sativus) adventitious root formation. The objective of this study was to test whether HO-1 is also involved in hydrogen sulfide (H2S)-induced adventitious root formation. Cucumber explants were treated with HO-1 inducer haemin and H2S donor sodium hydrosulfide (NaHS) in combination with the specific inhibitor of HO-1 zinc protoporphyrin IX (ZnPPIX), and their effects on cucumber adventitious root development in IAA-depleted explants were compared. The results showed that similar to inducible responses of haemin, NaHS brought about the induction of cucumber HO-1 transcripts (CsHO-1) and its protein levels, and thereafter adventitious root formation. A further experiment verified that H2S or HS- rather than other sulfur-containing components derived from NaHS was ascribed to the stimulation response. The inducible effect is specific for CsHO-1 because ZnPPIX significantly suppressed the above responses, and the inhibitory effects were reversed partially when 30% CO-saturated aqueous solution was added. Molecular evidence further suggested that the NaHS-triggered upregulation of target genes responsible for HO-1/CO-induced adventitious root formation, including CsDNAJ-1 and CsCDPK1/5, was inhibited significantly by ZnPPIX. These decreases were reversed obviously by the addition of CO aqueous solution. However, hypotaurine (HT), the H2S scavenger, could not influence the haemin- and CO-induced adventitious rooting in IAA-depleted cucumber explants. Together, the above results suggested that HO-1 was involved in H2S-induced cucumber adventitious root formation.

Fluorescence tomography (FT) is a promising molecular imaging technique that can spatially resolve both fluorophore concentration and lifetime parameters. However, recovered fluorophore parameters highly depend on the size and depth of the object due to the ill-posedness of the FT inverse problem. Structural a priori information from another high spatial resolution imaging modality has been demonstrated to significantly improve FT reconstruction accuracy. In this study, we have constructed a combined magnetic resonance imaging (MRI) and FT system for small animal imaging. A photo-multiplier tube (PMT) is used as the detector to acquire frequency domain FT measurements. This is the first MR-compatible time-resolved FT system that can reconstruct both fluorescence concentration and lifetime maps simultaneously. The performance of the hybrid system is evaluated with phantom studies. Two different fluorophores, Indocyanine Green (ICG) and 3-3′ Diethylthiatricarbocyanine Iodide (DTTCI), which have similar excitation and emission spectra but different lifetimes, are utilized. The fluorescence concentration and lifetime maps are both reconstructed with and without the structural a priori information obtained from MRI for comparison. We show that the hybrid system can accurately recover both fluorescence intensity and lifetime within 10% error for two 4.2 mm-diameter cylindrical objects embedded in a 38 mm-diameter cylindrical phantom when MRI structural a priori information is utilized.

In this paper we present first-of-its-kind spatially resolved enhancement kinetics of optical and magnetic resonance (MR) agents obtained by a combined MR and Diffuse Optical Tomography (MR-DOT) animal imaging system. A unique MR compatible fiber optic interface allows co-registration of MR and DOT data in space and time. High temporal resolution of the hybrid system permits acquisition of data in dynamic mode. Rats bearing a R3230 AC breast cancer tumor model are used for in vivo studies. Thirty-two optical and thirty MR images are acquired during a single imaging session that lasts nearly ten minutes. Both optical, indocyanine green (ICG), and MR contrast agents, gadolinium-DTPA (Gd-DTPA), are injected simultaneously after the acquisition of several baseline frames. Contrast enhancement time curves obtained by MR and DOT systems both indicate higher average enhancement in tumor regions, up to ten-fold for MRI and 3-fold for DOT, compared to close by non-tumor regions. This feasibility study is the first step towards clinical translation of this hybrid imaging platform. The ultimate aim is to use the enhancement kinetics of the optical agent ICG, which binds to plasma proteins, as complementary information to the kinetics of the MR agent Gd-DTPA, a small molecular agent that does not bind to plasma proteins, to better differentiate benign and malignant lesions.

Poly(ether-ester urethane)s (PUs) multiblock co-polymers were synthesized from telechelic hydroxylated poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) and poly(ethylene glycol) (PEG) via a melting polymerization (MP) process using 1,6-hexamethylene diisocyanate (HDI) as a non-toxic coupling agent for the first time. The PHBHHx segments and PEG segments in the multiblock co-polymers behaved as a hard, hydrophobic and a soft, hydrophilic part, respectively. Their chemical structures and molecular characteristics were studied by gel-permeation chromatography (GPC), (1)H-NMR and Fourier transform infrared spectroscopy (FT-IR). The PU produced via the MP method showed a higher molecular weight than those resulting from the solvent polymerization (SP) reported previously. Thermal properties showed enhanced thermal stability with semi-crystalline morphology via incorporation of PEG. The segments compositions evaluated from thermogravimetric analysis (TGA) two-step thermal decomposition profiles suggested that MP enhanced the reactivity of PEG compared with the SP process. It was in good agreement with those calculated from (1)H-NMR, as well as the precursor feed ratio, respectively. Water contact angle measurements revealed that surface hydrophilicity of the PUs was enhanced by incorporating the PEG segment into PHBHHx polymer backbone. The mechanical properties assessment of the PUs recorded an improved and adjustable ductility and toughness than pure PHBHHx while preserving the tensile strength. Samples synthesized via MP were resistant to hydrolytic and lipase degradation, yet the multiblock co-polymers incorporating the highest amount of PEG degraded at the highest rate. SEM studies revealed that the surface of the PU films became increasingly porous as the degradation proceeded. Implantation of PU in mouse abdominal cavity indicated that tissue regeneration and tissue compatibility of PU film was better than that of PHBHHx-only film.

Background Bezafibrate is widely used in clinics for its comparable angiogenic effect. Our research is to investigate the effect of bezafibrate on random skin flap survival. Materials and Methods The "McFarlane flap" rat models were established in 30 male Sprague-Dawley rats which were divided into two groups. The treatment group was given bezafibrate (400 mg/kg/day; gavage administration), and the control group received the vehicle. The flap surviving area was measured after 7 days, and the tissue samples were taken for histological analysis and edema measurement. Vascular endothelial growth factor (VEGF) was determined using immunohistochemical methods. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined with kits. Results Seven days after the operation, the surviving area in the treatment group was larger than in the control group (p 0.01). The expression of VEGF was increased in the treatment group compared with that in the control group. And the activity of SOD was lower in the treatment group compared with those in the control group (p 0.01). However, tissue edema, inflammatory cell infiltration, and MDA level were markedly lower in the treatment group than those in the control group (p 0.01). Conclusion Bezafibrate improves the survival of random skin flaps effectively.

Fluorescence diffuse optical tomography (FT) is an emerging molecular imaging technique that can spatially resolve both fluorophore concentration and lifetime parameters. In this study, we investigate the performance of a frequency-domain FT system for small inclusions that are embedded in a heterogeneous background. The results demonstrate that functional and structural a priori information is crucial to be able to recover both parameters with high accuracy. The functional a priori information is defined by the absorption and scattering maps at both excitation and emission wavelengths. Similarly, the boundaries of the small inclusion and different regions in the background are utilized as the structural a priori information. Without a priori information, the fluorophore concentration of a 5 mm inclusion in a 40 mm medium is recovered with 50% error, while the lifetime cannot be recovered at all. On the other hand, when both functional and structural information are available, the true lifetime can be recovered and the fluorophore concentration can be estimated only with 5% error. This study shows that a hybrid system that can acquire diffuse optical absorption tomography (DOT), FT and anatomical images in the same setting is essential to be able to recover the fluorophore concentration and lifetime accurately in vivo.

Conventional fluorescence tomography (FT) can recover the distribution of fluorescent agents within a highly scattering medium. However, poor spatial resolution remains its foremost limitation. Previously, we introduced a new fluorescence imaging technique termed "temperature-modulated fluorescence tomography" (TM-FT), which provides high-resolution images of fluorophore distribution. TM-FT is a multimodality technique that combines fluorescence imaging with focused ultrasound to locate thermo-sensitive fluorescence probes using a priori spatial information to drastically improve the resolution of conventional FT. In this paper, we present an extensive simulation study to evaluate the performance of the TM-FT technique on complex phantoms with multiple fluorescent targets of various sizes located at different depths. In addition, the performance of the TM-FT is tested in the presence of background fluorescence. The results obtained using our new method are systematically compared with those obtained with the conventional FT. Overall, TM-FT provides higher resolution and superior quantitative accuracy, making it an ideal candidate for in vivo preclinical and clinical imaging. For example, a 4mm diameter inclusion positioned in the middle of a synthetic slab geometry phantom (D:40 mm×W:100 mm) is recovered as an elongated object in the conventional FT (x=4.5 mm; y=10.4 mm), while TM-FT recovers it successfully in both directions (x=3.8 mm; y=4.6 mm). As a result, the quantitative accuracy of the TM-FT is superior because it recovers the concentration of the agent with a 22% error, which is in contrast with the 83% error of the conventional FT.

Background Random skin flaps can be used throughout the hands and fingers. Thymosin β4 can increase blood flow and reduce ischemia–reperfusion injury; the study was undertaken to investigate the effect of thymosin β4 on the survival of random skin flaps. Methods A total of 45 male Sprague–Dawley rats were used and subjected to a random-pattern skin flaps operation. Rats were randomly divided into three groups: a control group (group A: intraperitoneal injection of saline, 5 mg/kg/d) and two treatment groups (group B: intraperitoneal injection of thymosin β4, a single 5 mg/kg dose per day) and (group C: intraperitoneal injection of thymosin β4, 5 mg/kg dose twice per day). The flap surviving area was measured after 7 days, and tissue samples were stained with hematoxylin and eosin. Vascular endothelial growth factor (VEGF) expression was determined using immunohistochemical methods. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were examined with kits. Results Thymosin β4 significantly reduced the necrotic area in the treatment groups after 7 days compared with the control group, and the rats receiving thymosin β4 5 mg/kg twice per day had the highest survival rate. VEGF expression and SOD activity markedly increased in the treatment groups compared with the control group, whereas MDA levels were lower in the treatment groups than in the control group. Conclusion Thymosin β4 may have a dose-dependent effect to promote the survival of random skin flaps.

Androgen and its receptor (AR) have been reported to have pro- or antiapoptotic functions. However, the underlying molecular mechanism is incompletely understood. We report here that androgen and AR promote Bax-mediated apoptosis in prostate cancer cells. UV irradiation and ectopic expression of Bax induce apoptosis in AR-positive, but not AR-negative prostate cancer cells. UV- and Bax-induced apoptosis is abrogated in AR-positive cells that express small interference RNA (siRNA) of AR and is sensitized by reintroduction of AR into AR-negative cells. Although AR is able to promote Bax-mediated apoptosis independently of androgen, the promotion by AR can be further potentiated by androgen via AR-dependent transcription activation. AR is essential for the translocation of Bax to mitochondria in UV- or Bax-induced apoptosis. Inhibition of Bax expression by Bax siRNA suppresses UV-induced apoptosis in AR-positive cells. In addition, introduction of AR into AR-negative prostate cancer cells upregulates expression levels of the BH3-only protein Noxa, whereas inhibition of Noxa expression reduces the promotion by AR on UV-induced apoptosis. Thus, our results reveal a novel cross talk between the androgen/AR hormonal signaling pathway and the intrinsic apoptotic death pathway that determines the sensitivity of stress-induced apoptosis in prostate cancer cells.

We have developed a hybrid frequency domain fluorescence tomography and magnetic resonance imaging system (MRI) for small animal imaging. The main purpose of this system is to obtain quantitatively accurate fluorescence concentration and lifetime images using a multi-modality approach. In vivo experiments are undertaken to evaluate the system. We compare the recovered fluorescence parameters with and without MRI structural a priori information. In addition, we compare two optical background heterogeneity correction methods: Born normalization and utilizing diffuse optical tomography (DOT) functional a priori information. The results show that the concentration and lifetime of a 4.2-mm diameter indocyanine green inclusion located 15 mm deep inside a rat can be recovered with less than a 5% error when functional a priori information from DOT and structural a priori information from MRI are utilized.

Hydrogen gas (H2) is an endogenous gaseous molecule in plants. Although its reputation is as a “biologically inert gas”, recent results suggested that H2 has therapeutic antioxidant properties in animals and plays fundamental roles in plant responses to environmental stresses. However, whether H2 regulates root morphological patterns is largely unknown. In this report, hydrogen-rich water (HRW) was used to characterize H2 physiological roles and possible signaling transduction pathways in the promotion of adventitious root (AR) formation in cucumber explants. Our results showed that a 50% concentration of HRW was able to mimic the effect of hemin, an inducer of a carbon monoxide (CO) synthetic enzyme, and heme oxygenase-1 (HO-1), in restoring AR formation in comparison with the inhibition effect conferred by auxin-depletion treatment alone. It was further shown that the inducible effect of HRW could be further blocked by the co-treatment with N-1-naphthylphtalamic acid (NPA; an auxin transport inhibitor). The HRW-induced response, at least partially, was HO-1-dependent. This conclusion was supported by the fact that the exposure of cucumber explants to HRW up-regulates cucumber HO-1 gene expression and its protein levels. HRW-mediated induction of representative target genes related to auxin signaling and AR formation, such as CsDNAJ-1, CsCDPK1/5, CsCDC6, CsAUX22B-like, and CsAUX22D-like, and thereafter AR formation (particularly in the AR length) was differentially sensitive to the HO-1 inhibitor zinc protoporphyrin IX (ZnPP). Above blocking actions were clearly reversed by CO, further confirming that the above response was HO-1/CO-specific. However, the addition of a well-known antioxidant, ascorbic acid (AsA), failed to influence AR formation triggered by HRW, thus ruling out the involvement of redox homeostasis in this process. Together, these results indicated that HRW-induced adventitious rooting is, at least partially, correlated with the HO-1/CO-mediated responses. We also suggested that exogenous HRW treatment on plants might be a good option to induce root organogenesis.

We present a magnetic resonance (MR)-guided near-infrared dynamic contrast enhanced diffuse optical tomography (DCE-DOT) system for characterization of tumors using an optical contrast agent (ICG) and a MR contrast agent [Gd-diethylenetriaminepentaacetic acid (DTPA)] in a rat model. Both ICG and Gd-DTPA are injected and monitored simultaneously using a combined MRI-DOT system, resulting in accurate co-registration between two imaging modalities. Fisher rats bearing R3230 breast tumor are imaged using this hybrid system. For the first time, enhancement kinetics of the exogenous contrast ICG is recovered from the DCE-DOT data using MR anatomical a priori information. As tumors grow, they undergo necrosis and the tissue transforms from viable to necrotic. The results show that the physiological changes between viable and necrotic tissue can be differentiated more accurately based on the ICG enhancement kinetics when MR anatomical information is utilized.

Dynamic contrast enhanced MRI (DCE-MRI) has been proven to be the most sensitive modality in detecting breast lesions. Currently available MR contrast agent, Gd-DTPA, is a low molecular weight extracellular agent and can diffuse freely from the vascular space into interstitial space. Due to this reason, DCE-MRI has low sensitivity in differentiating benign and malignant tumors. Meanwhile, diffuse optical tomography (DOT) can be used to provide enhancement kinetics of an FDA approved optical contrast agent, ICG, which behaves like a large molecular weight optical agent due to its binding to albumin. The enhancement kinetics of ICG may have a potential to distinguish between the malignant and benign tumors and hence improve the specificity. Our group has developed a high speed hybrid MRI-DOT system. The DOT is a fully automated, MR-compatible, multi-frequency and multi-spectral imaging system. Fischer-344 rats bearing subcutaneous R3230 tumor are injected simultaneously with Gd-DTPA (0.1nmol/kg) and IC-Green (2.5mg/kg). The enhancement kinetics of both contrast agents are recorded simultaneously with this hybrid MRI-DOT system and evaluated for different tumors.

Fluorescence diffuse optical tomography (FT) is a molecular imaging technique that can create images of spatially resolved fluorophore concentrations and fluorescence lifetimes. One problem faced by FT is that the recovered fluorophore parameters greatly depend on the size and depth of the inclusion due to the ill-posedness of the FT inverse problem. Structural a priori information from imaging modalities with high spatial resolution is demonstrated to significantly improve the accuracy of the FT reconstruction. We have constructed a hybrid FT/MRI system for small animal imaging in this study. Near-infrared light was delivered and collected by optical fibers that connect the FT/MRI system to the interface in the MRI bore. We investigated the feasibility of a photo-multiplier tube (PMT) based detection system that acquired time-resolved data in the frequency domain. Phantom studies were used to evaluate the performance of the combined system. The concentration and lifetime maps were reconstructed with and without the structural a priori information obtained from MRI. ICG and DTTCI, two fluorophores with similar excitation and emission spectra but different lifetimes, were used in this evaluation. Specifically, we showed that the PMT-based frequency domain hybrid system was capable of differentiating between two fluorophores with different fluorescence lifetimes. Furthermore, this process was shown to be more accurate when MR a priori is used.

A gantry-based hybrid fluorescence and x-ray computed tomography (FT/CT) system is developed for quantitative molecular imaging. The performance of the dual modality FT/CT system is evaluated using an irregular shaped phantom with an inclusion containing Indocyanine-Green (ICG). The anatomical data from CT provides structural a priori information for the FT inverse problem. Although a 4.2 mm diameter inclusion can be resolved in the reconstructed concentration image without any a priori information, ICG concentration in the inclusion is recovered with 75% error. On the other hand, the error in the recovered ICG concentration reduces to 15% when a priori information from CT is utilized. The results demonstrate that accurate fluorophore concentration can only be obtained when x-ray CT structural a priori information is available.

Initial results from a novel dual modality preclinical imager which combines non-contact fluorescence tomography (FT) and x-ray computed tomography (CT) for preclinical functional and anatomical in vivo imaging are presented. The anatomical data from CT provides a priori information to the FT reconstruction to create overlaid functional and anatomical images with accurate localization and quantification of fluorophore distribution. Phantoms with inclusions containing Indocyanine-Green (ICG), and with heterogeneous backgrounds including iodine in compartments at different concentrations for CT contrast, have been imaged with the dual modality FT/CT system. Anatomical information from attenuation maps and optical morphological information from absorption and scattering maps are used as a priori information in the FT reconstruction. Although ICG inclusions can be located without the a priori information, the recovered ICG concentration shows 75% error. When the a priori information is utilized, the ICG concentration can be recovered with only 15% error. Developing the ability to accurately quantify fluorophore concentration in anatomical regions of interest may provide a powerful tool for in vivo small animal imaging.

Fluorescence diffuse optical tomography (FT) is a promising molecular imaging technique that can spatially resolve both fluorophore concentration and lifetime parameters. In this phantom study, we built a photo-multiplier tube (PMT) based single detection system that uses fiber bundles to collect light. Measurements were acquired both with a 1 mm diameter single fiber and a 6 mm diameter fiber bundle using the very same detection unit for comparison purposes. We demonstratethat the fluorescence concentration and lifetime can be well recovered for 6 mm diameter objects deeply embedded in an 80 mm diameter breast-sized phantom when the fiber bundle is utilized.

We demonstrate the feasibility of using a dual-modality fluorescence and x-ray computed tomography (CT) system for quantitative molecular imaging with phantom studies. A CCD based non-contact FT system, which can take measurements from multiple views was built. High-resolution X-Ray CT was used to obtain structural information from the phantom. A 3.6 mm diameter fluorescence inclusion was deeply embedded in the heterogeneous optical background. The results demonstrated that the fluorophore concentration can only be obtained accurately when guided by the a priori information provided by the x-ray CT.

Fluorescence diffuse optical tomography (FT) is an emerging molecular imaging technique that can spatially resolve both fluorophore concentration and lifetime parameters. In this study, we investigated the performance of a frequency domain FT system for inclusions with various sizes and contrast levels. Due to the ill-posedness of the FT problem, the fluorescence parameters can not be recovered accurately. The reconstructed fluorescence parameters depend on the signal to background contrast and size of the compartments containing the fluorophores. Recently, imaging with multiple modalities has become a popular trend. Different modalities give different information on the subject under investigation. Here, we evaluated the improvement in FT reconstruction when structural a priori information from a second imaging modality was incorporated. The results demonstrated that the structural a priori information was crucial to be able to recover both parameters with high accuracy. Without such a priori information, the same fluorophore concentration for different object sizes could not be recovered to the same value. On the other hand, when the structural a priori information was available, both fluorescence parameters could be recovered within 15% error for all the cases.

Conventional fluorescence tomography provides images of the distribution of fluorescent agents within highly scattering media, but suffers from poor spatial resolution. Previously, we introduced a new method termed “temperature-modulated fluorescence tomography” (TM-FT) that generates fluorescence images with high spatial resolution. TM-FT first uses focused ultrasound to locate the distribution of temperature-sensitive fluorescence probes. Afterward, this a priori information is utilized to improve the performance of the inverse solver for conventional fluorescence tomography and reveal quantitatively accurate fluorophore concentration maps. However, the disadvantage of this novel method is the long data acquisition time as the ultrasound beam was scanned in a step-and-shoot mode. In this Letter, we present a new, fast scanning method that reduces the imaging time 40 fold. By continuously scanning the ultrasound beam over a 50 mm by 25 mm field-of-view, high-resolution fluorescence images are obtained in less than 29 min, which is critical for in vivo small animal imaging.

In this work, a first-of-its-kind fully integrated tri-modality system that combines fluorescence, diffuse optical and x-ray tomography (FT/DOT/XCT) into the same setting is presented. The purpose of this system is to perform quantitative fluorescence tomography using multi-modality imaging approach. XCT anatomical information is used as structural priori while optical background heterogeneity information obtained by DOT measurements is used as functional priori. The performance of the hybrid system is evaluated using multi-modality phantoms. In particular, we show that a 2.4 mm diameter fluorescence inclusion located in a heterogeneous medium can be localized accurately with the functional a priori information, although the fluorophore concentration is recovered with 70% error. On the other hand, the fluorophore concentration can be accurately recovered within 8% error only when both DOT optical background functional and XCT structural a priori information are utilized to guide and constrain the FT reconstruction algorithm. (C) 2010 Optical Society of America

A fully integrated trimodality fluorescence, dif- fuse optical, and x-ray computed tomography FT/DOT/ XCT system for small animal imaging is reported in this work. The main purpose of this system is to obtain quan- titatively accurate fluorescence concentration images us- ing a multimodality approach. XCT offers anatomical in- formation, while DOT provides the necessary background optical property map to improve FT image accuracy. The quantitative accuracy of this trimodality system is demon- strated in vivo. In particular, we show that a 2-mm-diam fluorescence inclusion located 8m m deep in a nude mouse can only be localized when functional a priori information from DOT is available. However, the error in the recovered fluorophore concentration is nearly 87%. On the other hand, the fluorophore concentration can be accurately recovered within 2% error when both DOT functional and XCT structural a priori information are uti- lized together to guide and constrain the FT reconstruction algorithm. © 2010 Society of Photo-Optical Instrumentation Engineers.

We demonstrate the necessity of functional and structural a priori information for quantitative fluorescence tomography (FT) with phantom studies. Here the functional a priori information is defined as the optical properties of the heterogeneous background that can be measured by a diffuse optical tomography (DOT) system. A CCD-based noncontact hybrid FT/DOT system that could take measurements at multiple views was built. Multimodality phantoms with multiple compartments were constructed and used in the experiments to mimic a heterogeneous optical background. A 3.6 mm diameter object deeply embedded in a heterogeneous optical background could be localized without any a priori information, but the recovered fluorophore concentration only reached one tenth of the true concentration. On the other hand, the true fluorophore concentration could be recovered when both functional and structural a priori information is utilized to guide and constrain the FT reconstruction algorithm.

We present simultaneous measurement of enhancement kinetics of an optical and a magnetic resonance (MR) contrast agent in a small animal breast tumor model (R3230 ac) using a combined MR-diffuse optical tomographic (MR-DOT) imaging system. A mixture of a small molecular-weight MR contrast agent gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA) and a large molecular-weight optical contrast agent indocyanine green (ICG) was administered intravenously for multimodal dynamic imaging. Coregistration of optical and MR images was accomplished using agar-water-based markers. Using T(2) and dynamic T(1) weighted MR images, we divided the entire tumor into two regions of interest (ROI): a viable and a nonviable region. The absorption enhancements in the ROIs were calculated. An enhancement of the ICG was observed in the viable region. On the contrary, there was a lower enhancement in the nonviable region.