DIAGNOSTIC VALUE OF WHOLE BODY DIFFUSION WEIGHTED IMAGING FOR SCREENING PRIMARY TUMORS OF PATIENTS WITH METASTASES

Objective To evaluate the values of whole body diffusion weighted imaging （DWI） in screenmg pnmary unknown tumor in patients with metastases. Methods Totally, 34 patients with metastases of primary unknown tumors were scanned with whole body DWI, and conventional magnetic resonance （MR） imaging was performed if suspected lesions were detected. All the metastases including 27 cases of osseous metastases, 2 brain metastases, 2 liver metastases, 1 pulmonary multiple metastasis, 1 neck metastasis and 1 malignant ascites, were diagnosed by computed tomography, single photon emission computed tomography, or MR imaging. For the proven primary tumors diagnosed by biopsy or pathology of surgical specimens, apparent diffusion coefficient （ADC） values of the primary and metastatic lesions were measured respectively. The sensitivity and specificity of this technique for screening primary tumors were cvaluated. Results We found 24 cases with suspected primary lesions, in which 23 lesions were proved to be primary tumors, and 1 was proved to be benign lesion. And no definite primary lesion was found in 10 cases on whole body DWI, but in which 1 case was diagnosed with primary tumor by biopsy later, and the other 9 cases remained unknown within follow-up of over halfa year. The difference was not significant in ADC values between primary and metastatic lesions （P〉0.05）. The sensitivity and specificity of whole body DWI for searching primary tumors was 95.8% and 90.0%, respectively. Conclusion Combined with conventional MR scanning, whole body DWI can help to search primary lesions of patients with metastases.

Dihydrochalcones and phenanthrene derivatives from Fissistigma bracteolatum

Three dihydrochalcones derivatives 1-3, flavone 4 and phenanthrene derivative 5 were isolated, together with 9 known compofinds, from the air-dried root bark of Fissistigma bracteolatum Chatterjee. Their structures were determined by spectroscopic （NMR, MS） and chemical methodologies.

Clinical study of digital mammography,contrast-enhanced MRI as well as their combination in the diagnosis of breast cancer

Objective： To compare the effectiveness of digital mammography and MRI in the detection and diagnosis of breast cancer and to assess the value of these modalities as well as the combination of the two. Methods： Sixty-seven patients with surgery and pathology proved breast lesion （malignant, n = 32; benign, n = 46） underwent digital mammography and MRI, the pulse sequences included T1WI, T2WI, diffuse weighted imaging （DWI）, and dynamic contrast-enhanced MRI before surgery. Of the results of these two modalities, all lesions were classified into 5 groups according to BI-RADS classification, and the imaging findings were correlated to histopathology. The sensitivity and specificity of each modality as well as the combination of the two were calculated. Results： Of these 78 breasts lesions, The sensitivity was 78.13%% （25/32） for digital mammography and 93.75% （30/32） for MRI （P 〉 0.05）. The specificity was 73.91%% （34/46） and 89.13% （41/46） accordingly （P 〈 0.05）, both of them showed statistical difference. The sensitivity and specificity was 98.63% and 97.16% respectively as these two modalities were used in combination. Conclusion： Digital mammography in combination with MRI is helpful in the diagnosis of breast cancer, the sensitivity and specificity was enhanced when compared to that of single modality.

A Graphene Oxide-based Immuno-biosensor for Vibrio parahaemolyticus Detection

Vibrio parahaemolyticus is the leading causal agent of human acute gas- troenteritis. Real-time accurate detection means is the key to prevention and control of its spread. This study provided a novel detection strategy for realizing rapid and specific determination of V. parahaemolyticus by labeling its monoclonal antibody （Ab） with quantum dots （QDs）. The results showed that the fluorescence of these QDs-Ab bioconjugates was quenched by graphene oxide （GO） to produce a bacteri- um capture probe. And the optimal quenched concentration of GO was 60 ng/ml. When the bacterium capture probe was exposed to the target, green color fluores- cence was turned on by releasing the QDs-Ab due to the antibody antigen combi- nation. The detection limit of V. parahaemolyticus was 104 CFU/ml based on 3 times signal-to-noise ratio. The specificity of the FRET sensor towards V. para- haemolyticus was examined by comparing with controls such as V. splendidus, V. alginolyticus, Edwardsiella tarda and Aeromonas hydrophila with the same condition. The controls couldn＇t cause obvious fluorescence alteration, while the target resulted in significant fluorescence enhancement. This strategy could be further used as a universal method for any bacterial determination by changing the conjugated antibod- ies in early disease diagnosis. Therefore, the sensor has good potential to expand its application to the early diagnosis and determination of bacteria.

Isolation and Identification of Nicotiflorin and Narcissin from the Aerial Parts of Peucedanum aucheri Boiss.

Peucedanum aucheri Boiss. （Apiaceae） is a herbaceous wild plant native to Iran and is used in Iranian folk medicine as a diuretic and for the treatment of kidney disorders. Phytochemical investigation of different extracts prepared from the aerial part of P. aucheri Boiss. resulted to the isolation of two main flavonol glycosides from methanolic extract. Using comprehensive spectroscopic methods, including 1D and 2D nuclear magnetic resonance （NMR） spectroscopy and mass spectroscopy, chemical structure of isolated compounds were determined as kaempfrol-3-o-rutinoside （nicotiflorin） and isorhamnetin-3-o-rutinoside （narcissin）. Although narcissin has previously been isolated from P. ruthenicum, to the best of our knowledge, isolation of nicotiflorin from Peucedanum genus is reported for the first time.

System Size Resonance Associated with Canard Phenomenon in a Biological Cell System

The influence of internal noise on the calcium oscillations is studied. It is found that stochastic calcium oscillations occur when the internal noise is considered, while the corresponding deterministic dynamics only yields a steady state. Also,. the performance of such oscillations shows two maxima with the variation of the system size, indicating the occurrence of system size resonance. This behavior is found to be intimately connected with the canard phenomenon. Interestingly, it is also found that one of the optimal system sizes matches well with the real cell size, and such a match is robust to the variation of the control parameters.

Overview and developments in noninvasive diagnosis of nonalcoholic fatty liver disease

High prevalence of non-alcoholic fatty liver disease (NAFLD) and very diverse outcomes that are related to disease form and severity at presentation have made the search for noninvasive diagnostic tools in NAFLD one of the areas with most intense development in hepatology today.Various methods have been investigated in the recent years,including imaging methods like ultrasound and magnetic resonance imaging,different forms of liver stiffness measurement,various biomarkers of necroinflammatory processes (acute phase reactants,cytokines,markers of apoptosis),hyaluronic acid and other biomarkers of liver fibrosis.Multicomponent tests,scoring systems and diagnostic panels were also developed with the purposes of differentiating non-alcoholic steatohepatitis from simple steatosis or discriminating between various fibrosis stages.In all of the cases,performance of noninvasive methods was compared with liver biopsy,which is still considered to be a gold standard in diagnosis,but is by itself far from a perfect comparative measure.We present here the overview of the published data on various noninvasive diagnostic tools,some of which appear to be very promising,and we address as well some of still unresolved issues in this interesting field.

Some New Derivatives of 3H-benzo[b]Furo[3,2-f]- Benzimidazole with Expected Biological Activity

On the base of benzimidazole and benzofuran containing heterocyclic system, several derivatives with expected biological activity were synthesized. 2,3-diaminodibenzofuran was the primary substance. Adding various cyclic agents, 2-phenil was got, 2-（o-chlorophenil）, 2-（o-oxyphenil）, 2-chlorometyl- and 2-hydroximethyl-3H-benzo[b[furo（3,2-f] benzimidazoles. The aforementioned substances were characterized by IR and NMR spectroscopy.

Self-Assembled Monolayer of Lipoic Acid on Gold and Its Application to Rapid Determination of 2, 3, 7, 8-Tetrachlorodibenzo-p-Dioxin

Lipoic acid (LA) has received great attention in the area of gold surface functionalization. In this study, LA was employed as a linker for the attachment of antibody to the gold surface of surface plasmon resonance (SPR) chip. By using this chip in a homemade SPR immunosensor, low molecular weight compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) can be detected at a low level of 0.01 ng/mL. There is a good linear relationship(R2 =0.943 1) between the results of SPR biosensor and enzyme-linked immunosorbent assay(ELISA).

Magnetic field increase weight and water content in date palm （Phoenix dactylifera L.）

Magnetic field effects on different plant species have been subject of many studies in the last decade. Magnetic fields are known to induce changes in plant metabolism, growth and productivity. In this study, effect of magnetic field on date palm weight and water content has been investigated. Seedlings of date palm were treated with two types of magnetic fields in two separate experiments. In the first experiment, seedlings were treated with static magnetic field SMF using electromagnetic circuit set to produce three levels of magnetic field intensities 10, 50 and 100 mT for different durations （0, 30, 60, 120, 180 and 240 min）. In the second experiment seedlings were treated with alternating magnetic field AMF, using magnetic resonance imaging providing 1500 mT for 0, 1, 5, 10 and 15 min. After two months of exposure, plants growth parameters （fresh, dry weights and water content for both leaves and roots） were recorded. The measurements revealed that leaf fresh, dry weight and water content increased significantly in response to SMF treatment. Similarly, roots fresh weight and water content were increased significantly; however roots dry weight increasing were insignificant. In the second experiment, AMF has affected plant growth all parameters were increased significantly. Measurements reached the highest level at 15 min of exposure. This study revealed that magnetic fields affect date palm growth parameters by increasing osmotic pressure and water potential which increase water absorption and enhance flesh weight.

Biophysical studies of the interaction between a triazole derivative and bovine serum albumin by multi-spectroscopic and molecular modeling methods

The interaction between 3-thiol-4-(2,4-dichlorobenzylideneamino)-5-methyl-4H-1,2,4-triazole (CBTZ) and bovine serum albumin (BSA) under physiological conditions was investigated by fluorescence,UV-vis absorption and circular dichroism (CD) spectroscopy as well as molecular modeling methods. The result of fluorescence experiment indicates the static quenching as a result of the formation of the CBTZ-BSA complex. The binding constants (Ka) at different temperatures were calculated according to the modified Stern-Volmer equation. The enthalpy change (-H) and entropy change (-S) were determined based on the van′t Hoff equation. Both negative-H and-S indicated that van der Waals and hydrogen-bonding forces were the dominant intermolecular forces to stabilize the CBTZ-BSA complex. Site marker competitive replacement experiments demonstrated that binding of CBTZ to BSA primarily took place in sub-domain IIA (Sudlow's site I). The binding distance (r = 7.2 nm) between CBTZ and the tryptophan residue of BSA was estimated according to the theory of fluorescence resonance energy transfer (FRET). The conformational studies by circular dichroism (CD) and three-dimensional fluorescence spectroscopy showed that the presence of CBTZ induced minor changes of the secondary structure of BSA. Molecular modeling study further confirmed the binding mode obtained experimentally.

Nuclear magnetic resonance spectroscopy as a new approach for improvement of early diagnosis and risk stratification of prostate cancer

Prostate cancer （PCa） is the second most common male cancer worldwide and the fifth leading cause of death from cancer in men. Early detection and risk stratification is the most effective way to improve the survival of PCa patients. Current PCa biomarkers lack sufficient sensitivity and specificity to cancer. Metabolite biomarkers are evolving as a new diagnostic tool. This review is aimed to evaluate the potential of metabolite biomarkers for early detection, risk assessment, and monitoring of PCa. Of the 154 identified publications, 27 and 38 were original papers on urine and serum metabolomics, respectively. Nuclear magnetic resonance （NMR） is a promising method for measuring concentrations of metabolites in complex samples with good reproducibility, high sensitivity, and simple sample processing. Especially urine-based NMR metabolomics has the potential to be a cost-efficient method for the early detection of PCa, risk stratification, and monitoring treatment eff^cacy.

Surface Plasmon Resonance Based Sensing of Different Chemical and Biological Samples Using Admittance Loci Method

The admittance loci method plays an important role in the design of multilayer thin film structures. In this paper, admittance loci method has been explored theoretically for sensing of various chemical and biological samples based on surface plasmon resonance （SPR） phenomenon. A dielectric multilayer structure consisting of a Boro silicate glass （BSG） substrate, calcium fluoride （CaF2） and zirconium dioxide （ZrO2） along with different dielectric layers has been investigated. Moreover, admittance loci as well as SPR curves of metal-dielectric multilayer structure consisting of the BSG prism, gold metal film and various dielectric samples have been simulated in MATLAB environment. To validate the proposed simulation results, calibration curves have also been provided.

Biosensing strategy based on photocurrent quenching of quantum dots via energy resonance absorption

A new concept of energy resonance absorption for photocurrent quenching was proposed using a system of quantum dots(QDs) and the matched dye. The QDs were used as the photocurrent producer, and the dye had an absorption band overlapped with that of the QDs, which led to the resonance absorption of the excitation energy and thus decreased the photocurrent of QDs. By using porphyrin and fluorscein isothiocyanate isomer I as the resonance absorption dyes, the proposed mechanism was proved by UV-Vis spectra, photoluminescence spectra and photocurrent-to-wavelength response, respectively. The interaction of the absorption-matched dye with biomolecule could be conveniently used to introduce it into the photocurrent quenching system, leading to a simple switch-off biosensing method for detection of the biomolecule. As example, a label-free method was proposed for photoelectrochemical detection of target DNA. This method showed a detection range from 6.0 to 600 nmol/L with a detection limit of 2.5 nmol/L. The result demonstrated that the photocurrent quenching via energy resonance absorption not only contributed to the theoretical study of photoelectrochemistry, but also provided a universal tool for photoelectrochemical biosensing.

Fiber-Optic Surface Plasmon Resonance Sensor With Multi-Alternating Metal Layers for Biological Measurement

Optical fiber based SPR sensors have attracted more and more attention due to their unique advantages over the prism-based SPR sensors. A novel fiber-optic SPR sensor with multi-alternating metal layers for biochemical analysis is presented in this paper. Based on the fundamental SPR theory of the fiber optic sensing technology, we theoretically investigated the effects of the existence of alternating layers deposited on sensing region SPR wavelength changes. The emphasis was placed on the numerical simulation of the fiber-optic SPR sensor＇s sensitivity which could be affected by its technical parameters such as the metal thickness, number of alternating layers. Results showed that, compared to the normal SPR sensor with the single metal layer, the proposed sensor had a wider detecting range of the refractive index and higher sensitivity, which can find applications in biological analysis.

Time Delay Induced Stochastic Resonance in One Species Competition Ecosystem without a Periodic Signal

One-species competition ecosystem with noise and time delay was investigated as not driven by a periodic force.The results show that the time delay is responsible for stochastic resonance of the system as delay time is smaller than critical point of the Hopf bifurcation.

Recent advances in biological detection with magnetic nanoparticles as a useful tool

Magnetic nanoparticles have emerged as a powerful tool for magnetic resonance imaging, biodetection, drug delivery, and hyperthermia. This review focuses on the biological detection of magnetic nanoparticles as well as their physicochemical properties. Substantial progress in the sensitivity of detection has been made by developing variety of methods. Five applications of magnetic nanoparticles in biological detection are discussed in this review: magnetic separation, magnetic sensing, magnetic manipulation, magnetic catalysis, and signal enhancer for surface plasmon resonance(SPR). Finally, some future trends and perspectives in these research areas are outlined.

A localized surface plasmon resonance DNA biosensor based on gold nanospheres coated on the tip of the fiber

A localized surface plasmon resonance(LSPR) biosensor was prepared with gold nanospheres(Au NSs) coated on the tip face of the optical silica fiber. Au NSs with the sizes of 20 nm and 80 nm were used. The sensitivities of Au NS_(20 nm) and Au NS_(80 nm) modified sensors to bulk refractive index(RI) variation are 82.86 nm/RIU and 218.98 nm/RIU, respectively. The Au NS_(80 nm) modified sensor was used for the detection of 40 bases DNA hybridization and the limit of detection is 50 nmol/L, where the 40-bases DNA probe was covalently linked with Au NS_(80 nm). The complementary DNA sequence in tris-acetate-EDTA(TAE) buffer solution was detected as the target DNA. This fiber sensor has the advantages of small sample consumption, easy fabrication and high sensitivity.