bluuebunny/crossref_metadata_2025 huggingface dataset:
Outcome of acute hepatitis C is related to virus-specific CD4 function and maturation of antiviral memory CD8 responses
Authors: Urbani Simona , Amadei Barbara , Fisicaro Paola , Tola Daniela , Orlandini Alessandra , Sacchelli Luca , Mori Cristina , Missale Gabriele , Ferrari Carlo
Published: June 2006

A timely, efficient, and coordinated activation of both CD4 and CD8 T cell subsets following HCV infection is believed to be essential for HCV control. However, to what extent a failure of the individual T cell subsets can contribute to the high propensity of HCV to persist is still largely undefined. To address this issue, we analyzed the breadth, vigor, and quality of CD4 and CD8 responses simultaneously with panels of peptides covering the entire HCV sequence or containing the HLA-A2–binding motif, and with recombinant HCV proteins in 16 patients with acute HCV infection by tetramer staining, ELISPOT, and intracellular cytokine staining for interferon γ, interleukin (IL)-2, IL-4, and IL-10. Our results indicate that at clinical onset, CD8 responses are similarly weak and narrowly focused in both self-limited and chronically evolving infections. At this stage, CD4 responses are deeply impaired in patients with a chronic outcome as they are weak and of narrow specificity, unlike the strong, broad and T helper 1–oriented CD4 responses associated with resolving infections. Only patients able to finally control infection show maturation of CD8 memory sustained by progressive expansion of CD127+ CD8 cells. Thus, a poor CD8 response in the acute stage of infection may enhance the overall probability of chronic viral persistence.

In conclusion

, the presence of functional CD4 responses represents one of the factors dictating the fate of infection by directly contributing to control of the virus and by promoting maturation of protective memory CD8 responses.
Photoinduced Formation of Reactive Oxygen Species from the Acid Form of 6‐(Hydroxymethyl)pterin in Aqueous Solution
Authors: Thomas Andrés H. , Cabrerizo Romina , Vignoni Mariana , Erra‐Balsells Rosa , Cabrerizo Franco M. , Capparelli Alberto L.
Published: June 2006

The photochemistry of 6‐(hydroxymethyl)pterin (HPT; 1) in aqueous solution (pH 5–6) was investigated by irradiation at 350 nm at room temperature. The photochemical reactions of the acidic form 1a were followed by UV/VIS spectrophotometry, thin‐layer chromatography (TLC), high‐performance liquid chromatography (HPLC), and enzymatic methods for the determination of the superoxide anion radical (O$\rm{_2^{ \bullet - } }$) and hydrogen peroxide (H2O2). When 1a is exposed to UV‐A radiation, the intermediates 4 and 4′ are formed reacting with O2 to yield 6‐formylpterin (FPT; 5) and 6‐carboxypterin (CPT; 6) under formation of O$\rm{_2^{ \bullet - } }$ and H2O2 (Scheme 3). The quantum yields of the disappearance of HPT (1a) and of the formation of the photoproducts 5 and 6 were determined. HPT was investigated for its efficiency in singlet‐oxygen (1O2) production in acidic aqueous solution. The corresponding quantum yield of 1O2 production (ΦΔ) was 0.15 ± 0.02, as measured by the 1O2 luminescence in the near‐IR (1270 nm) upon continuous excitation of the sensitizer. However, 1O2 does not participate in the actual photooxidation of HPT (1a) to FPT (5) and CPT (6).
New Stephaoxocane Alkaloids from Stephania longa
Authors: Zhang Hua , Yue Jian‐Min
Published: June 2006

Three new stephaoxocane‐type alkaloids, stephalonganines A–C (1–3), together with the known eletefine (4), were isolated from the whole plant of Stephania longa. Their structures were fully characterized spectroscopically, and the absolute configurations of the new alkaloids were assigned by comparison of their circular‐dichroism (CD) data with those of 1,2‐dihydrostephaoxocanine (5), in combination with 2D‐NMR experiments.
Syntheses and Crystal Structures of Ammoniates with the Phenyl‐Substituted Polytin Anions Sn2Ph$\rm{_{\bf 4}^{{\bf 2} - } }$, cyclo‐Sn4Ph$\rm{_{\bf 4}^{{\bf 4} - } }$, and Sn6Ph$\rm{_{{\bf 12}}^{{\bf 2} - } }$
Authors: Wiesler Katharina , Suchentrunk Christof , Korber Nikolaus
Published: June 2006

The reaction of diphenyltin dichloride with the binary Zintl phase K4Sn9 in the presence of excess lithium and 18‐crown‐6 in liquid ammonia led to the ammoniate [K(18‐crown‐6)(NH3)2]2Sn2Ph4 (1). The analogous reaction with K4Ge9 and potassium in the absence of further alkali metal ligands resulted in the compound [K2(NH3)12]Sn6Ph12 ⋅ 4 NH3 (3). Cs6[Sn4Ph4](NH2)2 ⋅ 8 NH3 (2) was prepared by reacting diphenyltin dichloride with a surplus of caesium in liquid ammonia. The low‐temperature single‐crystal structure determinations show all compounds to contain phenyl‐substituted polyanions of tin. Compound 1 is built from Sn2Ph$\rm{_4^{2 - } }$ anions consisting of Sn dumbbells with two Ph substituents at each Sn‐atom. Compound 2 contains cyclo‐Sn4Ph$\rm{_4^{4 - } }$ anions formed by a four‐membered tin ring in butterfly conformation with one Ph substituent at each Sn‐atom in an (all‐trans)‐configuration. Sn6Ph$\rm{_{12}^{2 - } }$ in 3 is a zig‐zag Sn6 chain with two substituents at each of the Sn‐atoms. Both 1 and 3 have molecular counter cations, in the latter case the unprecedented dinuclear potassiumammine complex [K2(NH3)12]2+ is observed. Compound 2 shows a complicated three‐dimensional network of CsSn interactions.
One‐Pot Three‐Component Synthesis of Highly Functionalized 2,3‐Dihydro‐1,3‐dioxo‐1H,5H‐pyrazolo[1,2‐a][1,2,4]triazoles
Authors: Adib Mehdi , Sayahi Mohammad Hosein , Mahmoodi Niusha , Bijanzadeh Hamid Reza
Published: June 2006

The reactive 1 : 1 zwitterionic intermediate formed by the addition of isocyanides to dialkyl acetylenedicarboxylates was trapped with 4‐arylurazoles to produce the highly functionalized pyrazolo[1,2‐a][1,2,4]triazoles 5 in good yields (Table). The structures of the products 5a–h were corroborated spectroscopically (IR, 1H‐ and 13C‐NMR), by EI‐MS, and elemental analysis. A possible mechanism for this reaction is proposed (Scheme).
Synthetic dsDNA‐Binding Peptides Using Natural Compounds as Model
Authors: Borgions Filip , Ghyssels Daniel , Van Aerschot A. , Rozenski J. , Herdewijn Piet
Published: June 2006

We have developed a series of short DNA‐binding peptides containing newly synthesized, unnatural as well as natural amino acid building blocks. By a combinatorial‐library approach, oligopeptides were developed with moderate dsDNA‐binding affinities. Two strategies were used to further enhance the binding affinity of the lead peptides: Ac‐Arg‐Ual‐Sar‐Chi‐Chi‐Chi‐Arg‐NH2and Ac‐Arg‐Cbg‐Cha‐Chi‐Chi‐Tal‐Arg‐NH2. Site‐selective amino acid substitutions increased the binding affinities up to 2 × 10−5 M. Further enhancement of the binding affinities could be achieved by coupling of an acridine intercalating unit, using linker arms of different length and flexibility. With the introduction of a new lysine‐based acridine unit, different types of oligopeptide–acridine conjugates were designed using known dsDNA‐binding ligands as model compounds. The binding capacities of these new oligopeptide–acridine conjugates have been investigated by a fluorescent intercalator (ethidium bromide) displacement (FID) assay. With the synthesis of the dipeptide–acridine conjugates, binding affinities in the low micromolar range were obtained (6.4 × 10−6 M), which is similar to the binding strength of the well‐known DNA binderHoechst 33258.
New Phenolic Constituents from the Stems of Spatholobus suberectus
Authors: Zhang Shuwei , Xuan Lijiang
Published: June 2006

Three new phenolic compounds, 5‐O‐(β‐apiosyl‐(1 → 2)‐O‐β‐xylopyranosyl)gentisic acid (1), 1‐O‐(β‐apiosyl‐(1 → 6)‐O‐β‐glucopyranosyl)‐3‐O‐methylphloroglucinol (2), and 15‐O‐(α‐rhamnopyranosyl)aloe‐emodin (3), together with the known compound aloe emodin (4), were isolated from the stems of Spatholobus suberectus. Their structures were characterized by chemical and spectroscopic methods. The absolute configurations of the sugar units were not determined.
Regio‐ and Stereocontrolled Synthesis of (2R*,3R*,4R*)‐3,4‐Dichloro‐1,2,3,4,5,8‐hexahydronaphthalen‐2‐yl Acetate via Tandem SN2′ Reactions
Authors: Horasan‐Kishali Nurhan , Sahin Ertan , Kara Yunus
Published: June 2006

The hydroperoxy endoperoxide 3, obtained by photooxygenation of isotetralin (= 1,4,5,8‐tetrahydronaphthalene; 1), was reduced with thiourea, and the resulting intermediate 4 was converted, after acetylation with acetyl chloride, to the interesting, double‐chlorinated acetate 5 in an unprecedented tandem reaction (Scheme 1). The structures and relative configurations of 3 and 5 were determined by NMR spectroscopy and by single‐crystal X‐ray‐diffraction analyses (Figs. 1 and 2, resp.). A mechanistic rationalization for the conversion of 4 to 5 is proposed (Scheme 2).
Novel Synthesis of Mafenide and Other Amino Sulfonamides by Electrochemical Reduction of Cyano Sulfonamides
Authors: Lateef Shaik , Mohan Srinivasulu Reddy Krishna , Rameshraju Rudraraju , Reddy Srinivasulu Reddy Jayarama
Published: June 2006

Both aliphatic and aromatic amino sulfonamides such as mafenide (1a) were synthesized in good yields (80–86%) by direct electrochemical hydrogenation of the corresponding nitriles in an undivided cell containing a Ni cathode, a Pt anode, and Raney Ni as catalyst (Table 1). The reaction can be performed without external supply of pressurized gas by in situ generation of H2. Slightly elevated temperatures (45°) and low current densities (10 mA/cm2) are favorable conditions for this type of electrochemical nitrile hydrogenation. Our synthetic protocol does not require high‐pressure equipment or chemical hazards, is environmentally very friendly, and more economical than traditional methods. The concentration of adsorbed H. radicals on the catalyst surface can be easily controlled by adjusting the electric potential, which may lead to improved product selectivity and, at the same time, reduces the risk of explosion and fire.
Transcriptional profiling endometrial carcinomas microdissected from DES‐treated mice identifies changes in gene expression associated with estrogenic tumor promotion
Authors: Kabbarah Omar , Mallon Mary Ann , Pfeifer John D. , Goodfellow Paul J.
Published: June 2006

Exposure to unopposed estrogen is a potent risk factor for developing human endometrial cancer. However, little is known about the transcriptional changes elicited by estrogens in endometrial carcinogenesis, in part, because of genetic and environmental heterogeneity of human tumors. We have begun to chart the expression signatures of endometrial tumors promoted with the synthetic estrogen, diethylstilbestrol (DES), in inbred mice. As expected, laser‐capture‐microdissected endometrial cancers from DES‐treated mice displayed a large number of transcriptional changes when compared to uninvolved endometrial epithelium. Genes differentially expressed in carcinomas included cell adhesion and extracellular matrix genes (Decorin as 1 example), developmental genes (Hoxa11), and cytokine signaling genes (Socs3). The DES‐promoted carcinomas appeared to fall into 2 distinct transcriptional classes, and expression of the tumor suppressor Pten was among the top discriminators between the 2 cancer groups. Pten was down regulated in the majority of the DES‐promoted carcinomas, which is analogous to the frequent loss of PTEN expression in human endometrial tumors. Although preliminary, these observations suggest that the cancers that arise in the DES model bear similarities to human endometrial cancers and provide insights into transcriptional alterations that accompany estrogen‐driven endometrial carcinogenesis. © 2006 Wiley‐Liss, Inc.
Prognostic significance of matrix metalloproteinase‐7 in epithelial ovarian cancer and its relation to β‐catenin expression
Authors: Sillanpää Sari M. , Anttila Maarit A. , Voutilainen Kirsi A. , Ropponen Kirsi M. , Sironen Reijo K. , Saarikoski Serpo V. , Kosma Veli‐Matti
Published: June 2006

We investigated the expression and prognostic significance of matrix metalloproteinase (MMP) ‐7, its relation to β‐catenin expression and clinicopathological factors in epithelial ovarian cancer. The expression of MMP‐7 was analyzed immunohistochemically in a series of 284 primary epithelial ovarian cancers, their 36 metastases and 8 normal ovaries. In cancers with endometrioid histology, a high percentage area of MMP‐7 expression and an intense MMP‐7 signal was significantly associated with nuclear positivity of β‐catenin in cancer cells (p = 0.003, χ2 = 8.853 and p = 0.030, χ2 = 4.713, respectively). In all tumors and nonendometrioid subgroup, a low percentage area of MMP‐7 positive tumor cells was significantly correlated with a high histological grade of the tumor (p = 0.003 and 0.005, respectively), in all tumors also with advanced stage of the tumor (p = 0.002) and large primary residual tumor (p = 0.005). A 10‐year disease‐related survival (DRS) was significantly better when the percentage area of MMP‐7 expression in cancer cells was high, when compared to low (p = 0.0008). A high percentage area of intense MMP‐7 signal in cancer cells predicted a significantly more favorable DRS and recurrence‐free survival (RFS) (p = 0.0003 and 0.0052, respectively). In multivariate analysis, a high percentage area of intense MMP‐7 signal in tumor cells was an independent prognostic factor, predicting favorable DRS and RFS. The present study showed that intense MMP‐7 signal in tumor cells is an independent prognostic factor predicting better survival in epithelial ovarian cancer. © 2006 Wiley‐Liss, Inc.
M‐CAM expression as marker of poor prognosis in epithelial ovarian cancer
Authors: Aldovini Daniela , Demichelis Francesca , Doglioni Claudio , Di Vizio Dolores , Galligioni Enzo , Brugnara Sonia , Zeni Bruna , Griso Claudia , Pegoraro Cristina , Zannoni Marina , Gariboldi Manuela , Balladore Emanuela , Mezzanzanica Delia , Canevari Silvana , Barbareschi Mattia
Published: June 2006

Currently available clinico–pathologic criteria provide an imperfect assessment of outcome for patients with advanced epithelial ovarian cancer (EOC). Identification of prognostic factors related to tumor biology might improve this assessment. We investigated the prognostic significance of the melanoma cell adhesion molecule (M‐CAM) in EOC. Using the same antibody, M‐CAM expression was tested by Western blotting in protein extracts and by immunohistochemestry in tissue microarrays generated from 133 consecutively resected, well characterized EOC samples. Fisher test, Kaplan–Meier method and Cox proportional hazards analysis were used to relate M‐CAM expression to clinico–pathological variables and to time to progression (TTP) and overall survival (OS). In vitro biochemical analysis showed a progressively increased M‐CAM expression from normal to malignant cells. M‐CAM protein, detected immunohistochemically, was significantly associated with advanced tumor stage, serous and undifferentiated histotype, extent of residual disease and p53 accumulation. Presence or absence of M‐CAM significantly divided patients according to their TTP (median, 22 vs. 79 months, respectively; log‐rank p = 0.001) and OS (median, 42 vs. 131 months, respectively; log‐rank p = 0.0003). In the subgroup of advanced stage patients who achieved complete response after front‐line treatment, M‐CAM expression and absence of residual disease were significantly associated with shorter TTP (p = 0.003, HR 5.25, 95% Cl 1.79–15.41 and p = 0.011, HR 3.77, 95% Cl 1.36–10.49 respectively) at the multivariate level. In the same sub‐group of patients, M‐CAM expression remained the only parameter significantly associated with OS (p = 0.005, HR 3.35, 95% Cl 1.42–6.88). M‐CAM is a marker of early relapse and poorer outcome in EOC. In particular, M‐CAM expression identifies a subgroup of front‐line therapy‐responding patients who undergo dramatic relapses, thus helping to better select patients who might benefit from new/alternative therapeutic modalities. © 2006 Wiley‐Liss, Inc.
The expression levels of the transcriptional regulators p300 and CtBP modulate the correlations between SNAIL, ZEB1, E‐cadherin and vitamin D receptor in human colon carcinomas
Authors: Peña Cristina , García José Miguel , García Vanesa , Silva Javier , Domínguez Gemma , Rodríguez Rufo , Maximiano Constanza , García de Herreros Antonio , Muñoz Alberto , Bonilla Félix
Published: June 2006

ZEB1 and SNAIL repress CDH1 and induce epithelial–mesenchymal transition (EMT). However, SNAIL and ZEB1 also activate or regulate other target genes in different ways. For instance, vitamin D receptor (VDR), which activates CDH1 expression upon ligand binding, is repressed by SNAIL but induced by ZEB1. We examined whether the biological activity of SNAIL and ZEB1 in colon cancer is regulated by interacting cofactors. The mRNA expression levels of SNAIL and ZEB1, and of transcriptional regulators p300 and CtBP, were measured by RT‐PCR in tumor and normal tissue from 101 colon carcinoma patients. Overexpression of SNAIL was associated with down‐regulation of CDH1 and VDR (p = 0.004 and p < 0.001). CDH1 correlated with VDR (r = 0.49; p < 0.001). ZEB1 expression also correlated with VDR (r = 0.23; p = 0.019). However, when CtBP was strongly expressed, ZEB1 was inversely correlated with CDH1 (r = −0.39; p = 0.053). Furthermore, when there were elevated p300 expression levels, the correlation between expression of ZEB1 and VDR was stronger (r = 0.38; p = 0.070). Association between SNAIL expression and down‐regulation of CDH1 and VDR was lost in tumors in which p300 and CtBP were strongly expressed. These results indicate that the levels of expression of CtBP and p300 are critical for the action of SNAIL and ZEB1, which have a pivotal role in EMT, and show the importance of CtBP and p300 for tumor progression. © 2006 Wiley‐Liss, Inc.
Cancer‐specific targeting of an adenovirus‐delivered herpes simplex virus thymidine kinase suicide gene using translational control
Authors: Mathis J. Michael , Williams B. Jill , Sibley Don A. , Carroll Jennifer L. , Li Jie , Odaka Yoshinobu , Barlow Shayne , Nathan Cherie‐Ann O. , Li Benjamin D. L. , DeBenedetti Arrigo
Published: June 2006

Two technical hurdles, gene delivery and target specificity, have hindered the development of effective cancer gene therapies. In order to circumvent the problem of tumor specificity, the suicide gene, HSV‐1 thymidine kinase (HSV‐Tk), was modified with a complex 5′ upstream‐untranslated region (5′‐UTR) that limits efficient translation to cells expressing high levels of the translation initiation factor, eIF4E. Since previous studies have shown that most tumor cells express elevated levels of eIF4E, tumor‐specific gene delivery was optimized by incorporation of the 5′‐UTR‐modified suicide gene (HSV‐UTk) into an adenovirus vector (Ad‐CMV‐UTk). The efficacy of this novel approach of targeting suicide gene expression and limiting cytotoxicity by means of translational restriction was tested in vitro with the use of the human breast cancer cell lines (MCF‐7, MDA‐MB435, and ZR‐75‐1). As controls, normal MCF10A, HMEC, and HMSC cell lines that express relatively low levels of eIF4E were used. Real‐time reverse‐transcription polymerase chain reaction (RT‐PCR) was used to quantify HSV‐Tk mRNA for cells infected with Ad‐CMV‐UTk as well as with Ad‐CMV‐Tk (a control adenovirus in which HSV‐Tk is not regulated at the level of translation). Translation of HSV‐Tk in the Ad‐infected cells was measured by Western blot analysis. In addition, cytotoxicity was determined following treatment with the pro‐drug ganciclovir (GCV) using an MTT viability assay. Finally, microPET imaging was used to assess cancer cell‐specific expression of HSV‐Tk and expression in normal tissues in vivo after intraperitoneal injection of Ad‐CMV‐Tk or Ad‐CMV‐UTk. These data collectively showed enhanced cancer cell‐specific gene expression and reduced normal tissue gene expression for the Ad‐HSV‐UTk compared to the Ad‐CMV‐Tk, leading to increased cancer cell‐enhanced GCV cytotoxicity. These results indicate that translational targeting of suicide gene expression in tumor cells in vitro and in vivo is effective and may provide a platform for enhanced cancer gene therapy specificity. Copyright © 2006 John Wiley & Sons, Ltd.
Magnetic acoustic resonance immunoassay (MARIA): a multifrequency acoustic approach for the non‐labelled detection of biomolecular interactions
Authors: Araya‐Kleinsteuber Bernardita , Roque Ana C. A. , Kioupritzi Eleftheria , Stevenson Adrian C. , Lowe Christopher R.
Published: June 2006

A unique sensing platform, comprising an electromagnetic field detector and an acoustic resonator, has been used as a wireless system for remote sensing of biorecognition events. The MARS (Magnetic Acoustic Resonator Sensor) technique has proven useful for detecting the formation of protein multilayers derived from specific binding phenomena. The technique enables multifrequency analysis, without the need of electrodes attached to the sensing element, and also facilitates the in situ surface modification of the substrate for antibody attachment. The MARS sensor was utilized as the platform on which a standard immunoassay was carried out. Two different conditions for the attachment of the first antibody to the quartz surface were tested: (i) Adsorption of the antibody onto the surface of a bare quartz disc; (ii) covalent immobilization of the antibody to a chemically modified quartz surface. Both methods can be successfully utilized for the ‘label‐less’ detection of the biorecognition event between goat IgG and anti‐goat IgG by analysis of the multifrequency spectrum. Covalent attachment of the primary antibody results in a more efficient immobilization, with higher surface density, and a consistently enhanced response for the binding of the secondary antibody. This approach will be of interest to life scientists and biochemists that require high performance assay methodologies that do not use chemical labels. Copyright © 2006 John Wiley & Sons, Ltd.
Diagnosis of breast cancer using diffuse reflectance spectroscopy: Comparison of a Monte Carlo versus partial least squares analysis based feature extraction technique
Authors: Zhu Changfang , Palmer Gregory M. , Breslin Tara M. , Harter Josephine , Ramanujam Nirmala
Published: June 2006

Background and Objective

We explored the use of diffuse reflectance spectroscopy in the ultraviolet‐visible (UV‐VIS) spectrum for the diagnosis of breast cancer. A physical model (Monte Carlo inverse model) and an empirical model (partial least squares analysis) based approach, were compared for extracting diagnostic features from the diffuse reflectance spectra.

Study Design/Methods

The physical model and the empirical model were employed to extract features from diffuse reflectance spectra measured from freshly excised breast tissues. A subset of extracted features obtained using each method showed statistically significant differences between malignant and non‐malignant breast tissues. These features were separately input to a support vector machine (SVM) algorithm to classify each tissue sample as malignant or non‐malignant.

Results and Conclusions

The features extracted from the Monte Carlo based analysis were hemoglobin saturation, total hemoglobin concentration, beta‐carotene concentration and the mean (wavelength averaged) reduced scattering coefficient. Beta‐carotene concentration was positively correlated and the mean reduced scattering coefficient was negatively correlated with percent adipose tissue content in normal breast tissues. In addition, there was a statistically significant decrease in the beta‐carotene concentration and hemoglobin saturation, and a statistically significant increase in the mean reduced scattering coefficient in malignant tissues compared to non‐malignant tissues. The features extracted from the partial least squares analysis were a set of principal components. A subset of principal components showed that the diffuse reflectance spectra of malignant breast tissues displayed an increased intensity over wavelength range of 440–510 nm and a decreased intensity over wavelength range of 510–600 nm, relative to that of non‐malignant breast tissues. The diagnostic performance of the classification algorithms based on both feature extraction techniques yielded similar sensitivities and specificities of approximately 80% for discriminating between malignant and non‐malignant breast tissues. While both methods yielded similar classification accuracies, the model based approach provided insight into the physiological and structural features that discriminate between malignant and non‐malignant breast tissues. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Effects of low‐level laser therapy (LLLT) on the nuclear factor (NF)‐κB signaling pathway in traumatized muscle
Authors: Rizzi Carem Fetter , Mauriz José Luis , Freitas Corrêa Daniela Sousa , Moreira Andréa Janz , Zettler Claudio Galeano , Filippin Lidiane Isabel , Marroni Norma Possa , González‐Gallego Javier
Published: June 2006

Background and Objective

To investigate the effects of low‐level laser therapy (LLLT) on nuclear factor kappa B (NF‐κB) activation and inducible nitric oxide synthase (iNOS) expression in an experimental model of muscle trauma.

Study Design/Materials and Methods

Injury to the gastrocnemius muscle in the rat was produced by a single impact blunt trauma. A low‐level galium arsenide (Ga–As) laser (904 nm, 45 mW, and 5 J/cm2) was applied for 35 seconds duration, continuously.

Results

Histological abnormalities with increase in collagen concentration, and oxidative stress were observed after trauma. This was accompanied by activation of NF‐κB and upregulation of iNOS expression, whereas protein concentration of IκBα decreased. These effects were blocked by LLLT.

Conclusion

LLLT reduced the inflammatory response induced by trauma and was able to block the effects of reactive oxygen species (ROS) release and the activation of NF‐κB. The associated reduction of iNOS overexpression and collagen production suggest that the NF‐κB pathway may be a signaling route involved in the pathogenesis of muscle trauma. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Magnetic resonance imaging correlated with the histopathological effect of Pd‐bacteriopheophorbide (Tookad) photodynamic therapy on the normal canine prostate gland
Authors: Huang Zheng , Haider Masoom A. , Kraft Susan , Chen Qun , Blanc Dominique , Wilson Brian C. , Hetzel Fred W.
Published: June 2006

Background and Objective

To determine the optimal magnetic resonance imaging (MRI) methodology to assess photodynamic therapy (PDT)‐induced histopathological responses in the prostate.

Study Design/Materials and Methods

Laparotomy was performed in five healthy dogs. Cylindrical diffuser was placed in the prostates to deliver light of 50–300 J/cm at 150 mW/cm and 763 nm to activate IV‐injected Tookad (1 mg/kg b.w.). Fast spin echo (FSE) T2‐weighted, post‐contrast‐enhanced T1‐(CE‐T1) and diffusion weighted images (DWI) were obtained pre‐ and 2 days, 7 days, and 1 month post‐PDT. Radiological‐histopathological correlation was performed at 7 days (n = 4) and 1 month (n= 1) after PDT. A qualitative assessment of signal changes and apparent diffusion coefficient (ADC) mapping was performed.

Results

At 2 or 7 days post‐PDT, there was good spatial correlation between PDT‐induced hemorrhagic necrosis and unenhanced regions on CE‐T1 images. There was a rapidly and persistently enhancing rim corresponding to edema and inflammation. FSE T2 and DWI showed altered signal but did not clearly define necrosis in all cases. At 1 month, it was hard to correlate MR images to histopathologic changes as they represented a mixture of necrosis and developing fibrosis, which led to a mixed signal intensity and less demarcated contrast enhancement.

Conclusions

At 7 days after PDT, gadolinium DTPA contrast‐enhanced MRI is superior to DWI and T2 imaging in assessing the boundary of Tookad PDT‐induced tissue necrosis in the normal canine prostate. Lasers Surg. Med. © 2006 Wiley‐Liss, Inc.
Incoherent optical correlator for packet header recognition
Authors: Aljada Muhsen , Zheng Rong , Alameh Kamal E. , Al‐Begain Khalid
Published: June 2006

We propose an incoherent optical correlator for header recognition in optical packet switched networks, employing arrays of fiber Bragg gratings with different Bragg wavelengths and different reflectivity profiles. The proof of principle is experimentally demonstrated by recognizing a 4‐bit pattern at 2.2 Gb/s. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1725–1728, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21746
Hadamard speckle reduction for millimeter wave imaging
Authors: Jaeger Irina , Stiens Johan , Koers Gaetan , Poesen Gert , Vounckx Roger
Published: June 2006

Millimeter wave imaging technology makes possible imaging of phenomena, which are inaccessible to visible light, but suffer from speckles, produced by coherent sources. We report a 50% speckle reduction, measured with a free‐space vector network analyzer over the full W‐band. Our experiments demonstrate how Hadamard mask operates as a tunable filter. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1722–1725, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21747
A novel broad‐band microstrip radial stub resonator used in bias‐T application
Authors: Dehbashi Reza , Oskouei Hamidreza Dalili , Forooraghi Keyvan
Published: June 2006

A new reduced‐size broad‐band resonator is introduced. Two pairs of inclined‐radial butterfly stubs are connected at vertex of each other to form the resonator. The size of this band‐stop resonator is about 50% of a conventional two‐stub resonator. The scattering parameters are also improved, comparing to ordinary band‐stop resonators. The improvements of S11 (<20 dB), S12 (<3 dB), and S13 (<40 dB) are 73.68, 16.67, and 55.55%, respectively. The theoretical results are in good agreement with measurements. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1766–1770, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21748
Performance degradation of some on‐chip finite‐ground coplanar waveguide (FGCPW)‐built passive devices at high temperature
Authors: Yin Wen‐Yan , Mao Jun‐Fa , Shi Jing‐Lin , Sun Xiao‐Wei
Published: June 2006

At different temperatures, the performance degradation of on‐chip finite‐ground coplanar waveguides (FGCPWs) and FGCPW‐built meander‐line inductors are investigated in this article. These passive devices were all fabricated on a double‐layer polyimide and GaAs substrates and often used in monolithic microwave integrated circuits. It is shown that the increase in temperature causes the increase in series resistance or conductive loss of the metallization planes, and the temperature coefficient of series resistance depends on both frequency and metallization thickness. At given metal plane thickness and operating frequency, the conductive attenuation constant increases linearly with increasing temperature. Because of the increase in conductive loss, the maximum of Q‐factor of each meander‐line inductor decreases linearly with increasing temperature. While the temperature effect on the parasitic coupling between two parallel FGCPW stubs or between two neighboring inductors can be neglected, even the temperature reaches 438 K. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1754–1759, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21751
Effects of manufacturing artifacts on infrared filter performance
Authors: Qiang Rui , Chen Ji , Zhao Tianxiao , Han Keping , Ruiz Ariel , Ruchhoeft Paul , Morgan Mark
Published: June 2006

The effect of manufacturing artifacts on the performance of infrared frequency selective surfaces (FSS) is investigated in this article. For cross‐slot structures, these artifacts include slot length variation, slot width variation, the variation of spacing among elements, structural center broadening, and slot edge rounding. Quantitative measures of these effects on FSS transmission spectrum are obtained via a three‐dimensional (3D) periodic finite‐difference time‐domain method. The study shows that peak transmission intensity, resonant wavelength, and half‐max bandwidth of the transmission spectrum can be significantly affected by these manufacturing artifacts. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1749–1754, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21752
Broadband shorted patch antenna with monopole‐like radiation patterns
Authors: Liou Yen‐Yu , Row Jeen‐Sheen , Han Tuan‐Yung
Published: June 2006

The design of a shorted square patch antenna with broadband operation is presented. By placing an additional shorting wall at the edge of a planar inverted‐F antenna (PIFA) with a U‐shaped slot, the antenna can provide stable monopole‐like conical radiation patterns within the operating bandwidth. An antenna prototype designed for IEEE 802.11a band is completed and tested. The measured results show the 10 dB impedance bandwidth of more than 30% can be obtained while the side length of the square patch is about 0.3 free‐space wavelengths and the antenna height is less than 0.08 free‐space wavelengths. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1704–1707, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21753
Novel via‐less double‐sided parallel strip line to coplanar waveguide transition
Authors: Chen Jian‐Xin , Li Jia‐Lin , Xue Quan
Published: June 2006

New design of double‐sided parallel strip line to coplanar waveguide transition is proposed in this article. The via‐less structure gives convenience to the design and implement of the transition. A demonstration back‐to‐back transition circuit is designed and fabricated. Simulated and measured results are presented and show good agreement. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1717–1718, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21755
The sandwich structure with fractal patterns for microstrip lines
Authors: Wang Sheng , Li Lin , Chen Dong , Xu Peng G. , Zhao Xing‐Zhong
Published: June 2006

A sandwich structure with fractal pattern for microstrip line is proposed, in which a fractal pattern consisting of “H” is etched in the plane between the microstrip line and the ground plane of microstrip line. The transmission characteristics of that sandwich structure appear to have the multiple gaps and pass bands of electromagnetic waves is from 40 MHz to 10 GHz, and in particular the use of the fractal patterns array is increasing the gaps property of the gaps and pass bands. In this article, the transmission characteristics of one microstrip line with the sandwich structure normalized by 50 Ω are directly calculated by the finite different time domain (FDTD) method. Experimental observations are in good agreement with the result of FDTD simulations. Microstrip transmission lines incorporating a sandwich structure with fractal patterns exhibit band‐stops and slow‐wave characteristics, which can be exploited to reject unwanted frequency and to reduce the dimensions of the microstrip structure. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1714–1717, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21756
An optimum photonic system drives a phased array antenna
Authors: Koumasis A. , Kostarakis P.
Published: June 2006

In this article, a new true‐time‐delay photonic system is presented that drives a phased array antenna for beam steering and beamforming. It is optimized to use the least possible number of components and utilizes a very simple operation. It is tolerable in small differences of the excitation phase and distance between the elements of the phased array antenna. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1712–1714, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21757
The application of iterative solvers in discrete dipole approximation method for computing electromagnetic scattering
Authors: Fan Z. H. , Wang D. X. , Chen R. S. , Yung Edward K. N.
Published: June 2006

Several Krylov subspace iterative algorithms are compared as the solvers for the discrete dipole approximation method to analyze the electromagnetic scattering problem. Fast Fourier transform technique is exploited to accelerate the computation of matrix‐vector product. Numerical examples for homogeneous spheres indicate that the results of radar cross section agree well with the exact solutions. Some misleading concepts in literatures are clarified. We give a new comparison of the computational complexities of these methods. Faster solvers are recommended according to the size of scatterer. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1741–1746, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21760
Design and double negative property verification of C band left‐handed metamaterial
Authors: Meng Fan‐Yi , Wu Qun , Jin Bo‐Shi , Wang Hai‐Long , Wu Jian
Published: June 2006

In this article, a left‐handed (LH) metamaterial with miniaturized unit cell and broad bandwidth is designed. Its relative bandwidth is 56.4%, and the unit cell electrical size is 0.067 at the central frequency where the LH metamaterial is available. The effective permittivity and effective permeability are extracted from the transmission and reflection data at normal incidence for the LH metamaterial proposed here. The double negative (DNG) property is shown by the simultaneously negative effective permittivity and effective permeability and is confirmed by the equivalent circuit. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1732–1736, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21763
Compact sharp cutoff wide stopband low‐pass filter using defected ground structure and spurline
Authors: Dwari Santanu , Sanyal Subrata
Published: June 2006

A novel compact microstrip low‐pass filter is proposed using defected ground structure and spurline. The measured passband to stopband attenuation slope is more than 73 dB/GHz. Electrical length of the filter is less than 20% of the guided wavelength at 3 dB cutoff frequency. Measured stopband attenuation is greater than 20 dB over more than 17.5 GHz band. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1871–1873, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21765
Ultra wide‐band bow‐tie slot antenna fed by a CPW‐to‐CPW transition loaded with inductively coupled slots
Authors: Angelopoulos Evangelos S. , Anastopoulos Argyris Z. , Kaklamani Dimitra I.
Published: June 2006

This letter presents novel modified coplanar waveguide (CPW) bow‐tie slot printed antennas fed by a CPW‐to‐CPW transition. The proposed modules are miniature shaped, low‐profile radiators with bidirectional radiation characteristics, which can be optimally integrated in future ultra wide band transceivers. An innovative asymmetric bow‐tie configuration is introduced for the first time and the use of inductively coupled slots for bandwidth enhancement is additionally proposed and experimentally studied. The incorporated tapered CPW‐to‐CPW transition from Zin ≠ 50 Ω to Zin = 50 Ω offers upgraded impedance bandwidth and compatibility with 50 Ω CPW or coaxial lines. Details of the design procedure and experimental results exhibiting a bandwidth (VSWR <2) of 123% are presented. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1816–1820, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21768
Dual‐frequency F‐shaped shorted patch antenna
Authors: Lal J. , Kan H. K. , Rowe W. S. T.
Published: June 2006

This article presents a compact shorted patch antenna. The antenna is based on an F‐shaped printed conductor coaxially fed with an electromagnetically coupled shorted inverted F‐shaped antenna interleaved with each other. The overall antenna is then coupled with a rectangular ring. The antenna has dual characteristic features and its resonance frequency is at 1.85 and 2.42 GHz. The measured return loss bandwidth and its far field radiation patterns are presented. The gain of the antenna is 1.6 dBi. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1811–1812, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21770
Frequency agile microstrip antenna symmetrically loaded with tunnel diodes
Authors: Gautam A. K. , Vishvakarma B. R.
Published: June 2006

A new technique for designing the frequency agile microstrip antenna is presented. The frequency agility is achieved by symmetrical loading of two identical tunnel diodes in which the operating frequency of the rectangular microstrip antenna is electronically controlled by the bias voltage of tunnel diodes. Theoretical modal for an antenna is developed using modal cavity model and result are also simulated with MOM‐based simulator. The tuning range is found to be 55.92 MHz (6.67%), which is much better than earlier reported data. Antenna shows consistant return loss and radiation pattern for entire tunable frequency range. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1807–1810, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21771
Interrogation of fiber Bragg grating sensor based on Er‐doped fiber laser
Authors: Guo Wengang , Lu Fuyun , Luo Shaojun , Yang Xiufeng , Zhou Xiaoqun , Lu Chao
Published: June 2006

A novel interrogation of fiber Bragg grating (FBG) in a strain sensor, which is based on Er‐doped fiber laser's transient regime, is reported. The applied strain on FBG changes the laser cavity loss, which in turn modifies the laser's transient regime. The strain value can be obtained by measuring the build‐up time of the laser. This method translates wavelength shift information into time domain that can be accurately measured with low‐cost electronic devices. In the experiment, the strain sensitivity can be adjusted by simply controlling the pumping level of the laser, a sensitivity of 1.66 με/μs is achieved under fitful pumping level. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48:1904–1904, 2006; Published online in Wiley InterScience (www.interscience.wiley.com(. DOI 10.1002/mop.21773
Influences of photodarkening in highly doping ytterbium‐doped fiber on performance of fiber laser
Authors: Mao Qinghe , Zhu Zongjiu , Liu Wenqing , Lit John W. Y.
Published: June 2006

The influences of photodarkening in highly doping ytterbium‐doped fibers (YDFs) on the performance of fiber lasers were investigated in this study. The experimental results show that the threshold and the output power of the laser, respectively, increases and decreases over the pumping time, leading to the deterioration for the conversion efficiency of the laser. The deterioration is caused by the photodarkening of the YDF, which gives rise to additional loss for the YDF. This additional loss increases monotonically and irreversibly with the pump time. However, as the pumping time increases, the irreversible deteriorating process may be gradually fulfilled. The time needed for fulfilling this process depends on the length of the YDF and the pump used. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1902–1904, 2006; Published online in Wiley InterScience (www.interscience.wiley.com(. DOI 10.1002/mop.21774
A novel oscillator utilizing a corrugated CPW EBG structure with reduced phase noise and improved harmonic characteristics
Authors: Hwang Cheol Gyu , Myung Noh Hoon
Published: June 2006

This article presents a new microwave oscillator incorporating a corrugated coplanar waveguide (CCPW) electromagnetic bandgap structure as its terminating resonance component. The fully planar CCPW oscillator, oscillating at a frequency of 5.41 GHz, showed a phase noise reduction of 8 dB at 1 MHz offset and an increased second harmonic suppression of 10.16 dB and results in DC‐AC power efficiency enhancement of 7.2% when compared to those of a conventional CPW oscillator without the CCPW structure. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1843–1846, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21780
Dynamic fluctuations in a gain‐clamped EDFA chain in packet switched wdm optical transmissions
Authors: Thomas D. H. , von der Weid J. P.
Published: June 2006

Traffic load conditions can excite relaxation oscillations in a chain of gain‐clamped erbium‐doped fiber amplifiers (EDFA) in packet switched WDM optical networks. Crosstalk interaction depends on the delay between packets and cumulates along the amplifier chain, resulting in great power variations between packets, impairing system performance. © 2006 Wiley Periodicals,Inc.Microwave Opt Technol Lett 48:1894–1897, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21781
Spectral shaping of acousto‐optic tunable filter: A method to tune the bandwidth, wavelength, and attenuation
Authors: Veeriah S. , Faidz A. R. , Mishra V.
Published: June 2006

In this article, we presented a method, which will allow multiple parameter control of the 3‐dB bandwidth, centre‐notch wavelength, and attenuation level in a fiber‐based acousto‐optic tunable filter. The method basically involves the variation of the interaction length, RF frequency, and RF power on a single fiber device, to achieve multiple parameter tuning of the optical filter. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1781–1785, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21783
A novel power divider utilizing composite right/left‐handed transmission line
Authors: Li JiuSheng , Zou YongZhuo , He SaiLing
Published: June 2006

A novel composite right/left‐handed transmission line unit is proposed. Using the structure, a new power divider is developed. By adjusting the parameters of the capacitors and the inductors, the simulation results show that the power divider has perfectly symmetric power division at 1.24 GHz, return loss up to −38 dB with the transmitted power being close to −3 dB (−3.01 dB). In addition, the performances of the novel power divider are demonstrated experimentally. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1776–1779, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21785
Fiber‐optic acoustic transducer utilizing a dual‐core collimator combined with a reflective micromirror
Authors: Song Ju‐Han , Lee Sang‐Shin
Published: June 2006

A photonic acoustic transducer utilizing a dual‐core fiber collimator and a membrane type micromirror was proposed and demonstrated. The collimator and the mirror serve as a compact optical head and a reflective diaphragm, respectively. The micromirror diaphragm is suspended by a silicon bar connected to a frame, allowing for displacement induced by acoustic waves. The optical head incorporating dual collimators integrated in a single housing provides light to and receives it from the diaphragm. It facilitates the initial adjustment of the distance between it and the diaphragm, thanks to its slowly varying beam profiles. For the proposed acoustic transducer, the static characteristics were measured to find the operation point defined as the optimum distance between the head and the diaphragm, and a frequency response with a variation of ∼±5 dB was achieved for the range of up to 3 kHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1833–1836, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21789