Vol.21,

In SSRF, the design of 1st crystal cooling geometry of double crystal monochromator with sagittal focus is mainly reported by China. Our simulation indicates that the broadening of the full width at half maximum of the rocking curve of the double crystal monochromator induced by the heat load is about 3.7 μrad, and is in agreement with the experimental value of 5 μrad. Our scheme showed that the photon flux is reliably linear with electron current of the storage ring, which is extracted from the monochromator.

434

Accelerator-based target design and optimization is an approach for neutron generation. The target plays an important role for a neutron source on an electron accelerator. For optimizing a neutron source using 10 MeV electron beams of Rhodotron-TT200, Pb, Ta, or W alloys with Be were calculated as photo-neutron converter. The neutron yield, flux and energy were simulated using the MCNPX code. The results indicate that a 10 MeV electron beam is capable of producing high-intensity neutron flux of 10¹³n·cm^–2·s^–1 with average energy of 0.8 MeV.

505

Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the PBDEs homologues, is investigated by electron beam irradiation of its ethanol/water solution (reduction system) and acetonitrile/water solution (oxidation system). The radiolytic products were determined by GC coupled with electron capture detector, and the reaction rate constant of e_sol^– in the reduction system was measured at 2.7×10¹⁰ L·mol^–1·s^–1 by pulsed radiolysis. The results show that the BDE-3 concentration affects strongly the decomposition ratio in the alkali solution, and the reduction system has a higher BDE-3 decomposition rate than the oxidation system. This indicates that the BDE-3 was reduced by effectively capturing e_sol^– in radiolytic process.

579

In this work, the natural radionuclide concentrations of the ²²⁶Ra, ²²⁸Ra, ²³²Th and ⁴⁰K were estimated from samples of cattle and poultry fodder, South Valley University farms and Qena Governorate farm, Qena, Upper Egypt. The radionuclide concentrations and annual consumption rate of twenty-nine animal fodders were analyzed using low-level γ-spectrometer, including a mixture fodder, silage, hay, rice straw, and poultry fodder. The irradiation risk of human health was assessed due to indirect ingestion of the beef, milk, poultry and egg, the annual effective dose of the radionuclides for the local consumer was 2.7, 14, 0.1, and 0.14 µSv·y^–1, respectively.

488

CdSe quantum dots (QDs) were prepared at room temperature by E-beam irradiation of the solution, using ethylene diamine tetraacetic acid as stabilizer. Silica-coated CdSe QDs were made in water-in-oil microemulsion, while amino groups were introduced synchronously onto the nanoparticles by copolymerization of 3-aminopropyl- trimethoxysilane and tetraethyl orthosilicate. The results of TEM imaging, fluorescent spectroscopy and photostability tests show that the QDs are of uniform spherical size (200±8 nm), monodispersity, and high fluorescence and photostability.

402

Epidermal growth factor receptor (EGFR) plays a critical role in proliferation, apoptosis, angiogenesis, invasiveness and distant metastasis of tumors. In this study, the tumor targeting properties of anti-EGFR monoclonal antibody (mAb) LA22 in a colon cancer mouse model are evaluated. The results from flow cytometry assay and immunofluorescent staining clearly showed that HT-29 human colon cancer cells were EGFR positive, and the binding of mAb LA22 to the HT-29 cell surface was specific. The saturation binding experiment of ¹²⁵I-LA22 to HT-29 cells revealed that LA22 possessed moderate affinity to EGFR with the Kd value calculated to be 3.28±0.76 nM. The in vivo γ imaging demonstrated the specific accumulation of ¹²⁵I-LA22 in HT-29 tumor xenografts. The specific tumor targeting properties of mAb LA22 make it a good candidate for tumor targeted radioimmunotherapy of EGFR-positive tumors when it is labeled with therapeutic nuclides, such as ¹³¹I, ¹⁷⁷Lu, or ⁹⁰Y.

497

In this paper, the joint imaging of ^99mTcO₄^‾ and ^99mTc-methoxy isobutyl isonitrile was compared with neck Color Doppler Ultrasonography (CDU) to identify its value in thyroid carcinoma, postoperative recurrence or cervical metastases. Thyroid carcinoma patients (150 operated and 21 re-operated with suspected postoperative recurrence or cervical metastases) were retrospectively analyzed. Taking the pathological result as the gold standard, the thyroid foci (437 cases), the thyroid foci of ≥1-cm diameter (215 cases) and the suspected postoperative recurrence or cervical metastases (87 cases) were compared by diagnostic results of the joint imaging and the neck CDU. The sensitivity, specificity and accuracy of the joint imaging were 64.18%, 80.00% and 67.82%, and 44.78%, 40.00% and 43.68%, respectively, for the cases with suspected postoperative recurrence or cervical metastases. For thyroid carcinoma of ≥1-cm diameter, the sensitivity of the joint imaging was 97.75%, and the neck CDU was 89.89%, but both specificity and accuracy was similar for thyroid carcinoma independence on their diameter. For thyroid carcinoma, the sensitivity of the joint imaging was 81.99%, and the neck CDU was 89.10%. The results show that the joint imaging is sensitive for large diameter thyroid carcinoma.

564

In this paper, ¹⁸F-FDG PET/CT data of 19 malignant SINs (small intestinal neoplasms) were consecutively reviewed. Nnine patients accepted PET/CT scan for preoperative diagnosis and staging, while ten patients presented follow-up after treatment and restaging. The results were correlated with abdomen enhanced CT and surgical pathological findings. Abdominal pain and weight loss were the most common findings. About 16% SINs located in the duodenum, 52% in the jejunum and 32% in the ileum. Lymphoma was the most frequent neoplasms. PET/CT revealed residual or recurrent malignant SINs in 5 patients who had negative or non-definite findings by abdomen CT and demonstrated extra-abdomen metastasis in 3 patients. Clinical decisions of treatment were changed for 6 patients after PET/CT examinations. The ¹⁸F-FDG PET/CT were better than CT in accuracy, negative predictive value and positive predictive value (89.5% vs 68.4%, 100% vs 66.7%, and 81.8% vs 69.2%, respectively). Whole body ¹⁸F-FDG PET/CT may be an effective molecular imaging method for staging and restaging of malignant SINs.

459

To investigate human sodium/iodide symporter (hNIS) induced iodine uptake in human lung adeno- carcinoma via baculovirus, a recombinant baculovirus encoding hNIS gene was constructed under the control of CMV promoter (Bac-CMV-hNIS). In vitro, baculovirus infected A549 cells accumulated about 27 times more ¹²⁵I than that of noninfected cells. The ¹²⁵I uptake was maximal after 30-min incubation of the cells, and efflux of the radioactivity was rapid, with 50% lost during the first 2 min after ¹²⁵I-containing medium had been replaced by nonradioactive medium. Competition experiments in the presence of sodium perchlorate revealed a dose-dependent decrease of ¹²⁵I uptake. Bac-CMV-hNIS infected tumor cells were selectively killed by exposure to ¹³¹I, as revealed by clonogenic assays. In nude mice, Bac-CMV-hNIS infected A549 cells accumulated more ¹³¹I than that of the control monitored by 1-h scintigraphy after ¹³¹I administration. The transduction of hNIS gene through baculovirus is sufficient to induce iodine transporting in A549 cells in vitro and in vivo, outlining the potential of this novel tumor gene imaging approach. But a rapid efflux of radioactivity from the tumor was shown in vivo and the in vivo therapy test showed no sign of effect.

626

Technetium-99m-labeled-5-{2-sulfanylethyl-[2-(2-sulfanylethylamino)acetyl]amino}-methyl-2′-deoxy- uridine (^99mTc-ANMdU) was reported. The precursor ANMdU was synthesized by six-step reactions and all intermediates were verified with MS and ¹HNMR. Using SnCl₂ as reducing agent, a labeling reaction was carried out at 100°C for 30 min. The radiochemical purity of the ^99mTc-ANMdU was 96.68%. Partition coefficients were 0.92 and 0.70 at pH 7.0 and 7.4 of the phosphate buffer saline, respectively. Biodistribution of ^99mTc-ANMdU in normal mice showed that the initial uptake of ^99mTc-ANMdU in vivo and the clearance was rapid.

435

Excitation functions for ¹⁶⁹Yb production on low-medium energy accelerators, i.e. proton on ¹⁶⁹Tm and ^natYb, deuteron on ¹⁶⁹Tm, and ⁴He ion on ^natEr, were calculated by the ALICE/ASH and TALYS-1.0 codes. The target thickness was predicted by SRIM code. Theoretical integral yield for each reaction was compared with experimental data. The radionuclide purity of ¹⁶⁹Yb from the ¹⁶⁹Tm(p, n)¹⁶⁹Yb reaction was determined, and maximum cross section predicted by the ALICE/ASH and TALYS-1.0 codes was about 182 and 154 mb at 11 and at 9 MeV, respectively.

454

In order to measure differential cross sections of the ¹⁰B(n,α)⁷Li reaction induced by MeV neutrons using the forward-backward coincidence method, a thin film ¹⁰B sample was designed and the ¹⁰B atom number was determined with a reference ¹⁰B film sample. Alpha counts of the ¹⁰B(n_th,α)⁷Li reaction from the ¹⁰B thin film and the reference sample were measured using a gridded ionization chamber and thermal neutrons, which were moderated and thermalized by paraffin from fast neutrons produced in D(d,n)³He reaction on a 4.5 MV Van de Graaff. The neutron flux was normalized by measuring the fission yield of a small ²³⁸U fission chamber.

419

A CMOS front-end integrated circuit consisting of 16 identical analog channels is proposed for semiconductor radiation detectors. Each of the 16 channels has a low noise charge sensitive amplifier, a pulse shaper, a peak detect and hold circuit and a discriminator, while analog voltage and channel address are routed off the chip. It can accommodate both electron and hole collection with selectable gain and peaking time. Sequential and sparse readout, combining with self-trigger and external trigger, makes four readout modes. The circuit is implemented in a 0.35 μm DP4M (double-poly-quad-metal) CMOS technology with an area of 2.5×1.54 mm² and power dissipation of 60 mW. A single channel chip is tested with Verigy 93000. The gain is adjustable from 13 to 130 mV·fC^–1 while the peaking time varies between 0.7 and 1.6 μs. The linearity is more than 99% and the equivalent noise charge is about 600e.

681

In this paper, the design of a coarse-fine interpolation Time-to-Digital Converter (TDC) is implemented in an ALTERA's Cyclone FPGA. The carry-select chain performs as the tapped delay line. The Logic Array Block (LAB) having a propagation delay of 165 ps in the chain is synthesized as delay cell. Coarse counters triggered by the global clock count the more significant bits of the time data. This clock is also fed through the delay line, and LABs create the copies. The replicas are latched by the tested event signal, and the less significant bits are encoded from the latched binary bits. Single-shot resolution of the TDC can be 60 ps. The worst Differential Nonlinearity (DNL) is about 0.2 Least Significant Bit (LSB, 165 ps in this TDC module), and the Integral Nonlinearity (INL) is 0.6 LSB. In comparison with other architectures using the synchronous global clock to sample the taps, this architecture consumed less electric power and logic cells, and is more stable.

484