[en] Objective: To evaluate the imaging manifestations of cerebral gumma. Methods: Three cases of surgically proved cerebral gumma were analyzed. All patients had history of ultra-marriage sexual life, and the laboratory tests, including the serums and/or the cerebrospinal fluid test, highly indicated the diagnosis of syphilis. Pathological results demonstrated cerebral gumma after operation. Results: On CT scan, case 1 showed a 5.0 cm x 3.5 cm hypo-density area at left temporal lobe with obvious mass effect, and post-contrast CT scan revealed a rim enhancement. MR scanning was not performed. In case 2, a mixture lesion was detected on right frontal lobe on pre-contrast CT scan, and spot-like central enhancement and mild mass effect were demonstrated on postcontrast CT scan. Pre-contrast T₁WI showed 2 round lesions situated at right frontal lobe (1.5 cm in diameter) and right periventricular areas (1.0 cm in diameter), separately, which showed iso-signal on T₁WI and hyper-signal on T₂WI, and ring-like enhancement with slight compression of the right lateral ventricle. In case 3, CT plain scan demonstrated multiple hypo-dense lesions, most of the lesions located on both frontal lobe and left temporal lobe, and enhanced CT scan was not performed. MR imaging revealed many nodule and mass lesions with hypo-signal on T₁WI and hyper-signal on T₂WI, located on both hemispheres with nodular or circular enhancement after injection of contrast media. Conclusion: The imaging manifestations of cerebral gumma were nonspecific. Thus, the preoperational diagnosis should be made combining the clinical, laboratory, and imaging data

[en] This paper presents a low power and high efficiency high voltage generator circuit embedded in electrically erasable programmable read-only memory (EEPROM). The low power is minimized by a capacitance divider circuit and a regulator circuit using the controlling clock switch technique. The high efficiency is dependent on the zero threshold voltage (V_th) MOSFET and the charge transfer switch (CTS) charge pump. The proposed high voltage generator circuit has been implemented in a 0.35 μm EEPROM CMOS process. Measured results show that the proposed high voltage generator circuit has a low power consumption of about 150.48 μW and a higher pumping efficiency (83.3%) than previously reported circuits. This high voltage generator circuit can also be widely used in low-power flash devices due to its high efficiency and low power dissipation. (semiconductor integrated circuits)

[en] This paper presents a realization of a silicon-based standard CMOS, fully differential optoelectronic integrated receiver based on a metal-semiconductor-metal light detector (MSM photodetector). In the optical receiver, two MSM photodetectors are integrated to convert the incident light signal into a pair of fully differential photogenerated currents. The optoelectronic integrated receiver was designed and implemented in a chartered 0.35 μm, 3.3 V standard CMOS process. For 850 nm wavelength, it achieves a 1 GHz 3 dB bandwidth due to the MSM photodetector's low capacitance and high intrinsic bandwidth. In addition, it has a transimpedance gain of 98.75 dBΩ, and an equivalent input integrated referred noise current of 283 nA from 1 Hz up to -3 dB frequency.

[en] This paper presents a millimeter wave (mm-wave) oscillator that generates signal at 36.56 GHz. The mm-wave oscillator is realized in a UMC 0.18 μm CMOS process. The linear superposition (LS) technique breaks through the limit of cut-off frequency (f_T), and realizes a much higher oscillation than f_T. Measurement results show that the LS oscillator produces a calibrated −37.17 dBm output power when biased at 1.8 V; the output power of fundamental signal is −10.85 dBm after calibration. The measured phase noise at 1 MHz frequency offset is −112.54 dBc/Hz at the frequency of 9.14 GHz. This circuit can be properly applied to mm-wave communication systems with advantages of low cost and high integration density. (semiconductor integrated circuits)

[en] A standard CMOS optical interconnect is proposed, including an octagonal-annular emitter, a field oxide, metal 1-PSG/BPSG-metal 2 dual waveguide, and an ultra high-sensitivity optical receiver integrated with a fingered P+/N-well/P-sub dual photodiode detector. The optical interconnect is implemented in a Chartered 3.3-V 0.35-μm standard analog CMOS process with two schemes for the research of the substrate noise coupling effect on the optical interconnect performance: with or without a GND-guardring around the emitter. The experiment results show that the optical interconnect can work at 100 kHz, and it is feasible to implement optical interconnects in standard CMOS processes.

[en] A monolithically integrated optical receiver, including the photodetector, has been realized in Chartered 0.35 μm EEPROM CMOS technology for 850 nm optical communication. The optical receiver consists of a differential photodetector, a differential transimpedance amplifier, three limiting amplifiers and an output circuit. The experiment results show that the receiver achieves an 875 MHz 3 dB bandwidth, and a data rate of 1.5 Gb/s is achieved at a bit-error-rate of 10^-9. The chip dissipates 60 mW under a single 3.3 V supply. (semiconductor integrated circuits)

[en] A novel matching method between the power amplifier (PA) and antenna of an active or semi-active RFID tag is presented. A PCB dipole antenna is used as the resonance inductor of a differential power amplifier. The total PA chip area is reduced greatly to only 240 × 70 μm² in a 0.18 μm CMOS process due to saving two on-chip integrated inductors. Operating in class AB with a 1.8 V supply voltage and 2.45 GHz input signal, the PA shows a measured output power of 8 dBm at the 1 dB compression point. (semiconductor integrated circuits)

[en] Highlights: • A Mg(OH)₂/talc nanocomposite was prepared by hydrothermal method. • The occurrence state of magnesium had great influence on the adsorption of Pb(II). • Adsorption mechanism was Electrostatic attraction and ion exchange. • Adsorption occurred on non-uniform surface with multilayer. -- Abstract: It is of great significance in the resource utilization to make full use of the magnesium in the low-grade mineral to prepare new adsorption materials. In this paper, a Mg(OH)₂/talc nanocomposite was prepared by migrating part of Mg²⁺ from the talc internal structure to the outer surface through a facile acid leaching, coprecipitation and hydrothermal method. The maximum adsorption capacity of Mg(OH)₂/talc was 483.33 mg/g, which was significantly improved compared with that of Acid-activated Talc (4.79 mg/g) and pristine talc (259.17 mg/g). The main adsorption mechanism of Mg(OH)₂/talc for Pb(II) ions involved electrostatic attraction and ion exchange. Adsorption and desorption cycle experiment showed that, although Mg(OH)₂/talc provides a large adsorption capacity for the first time, but the second adsorption capacity decreased by 42%, the third to the fifth kept stable adsorption capacity. This results indicated that the surface of magnesium hydroxide was not stable, only used it once. While magnesium hydroxyl in talc was stable, it could provide stable cycle performance. This work can provide reference for efficient utilization of clay minerals and design novel cost-efficient adsorbents.

[en] A glassy carbon electrode (GCE) was coated with N-doped carbon-modified palygorskite and used as an electrochemical sensor for determination of Pb(II) by differential pulse anodic stripping voltammetry. To obtain high reproducibility and sensitivity, optimum experimental conditions for lead deposition are studied. Voltammetric responses of the modified GCE prepared with different ratios of carbon and palygorskite are examined under same conditions. Compared with a bare GCE, a N-doped carbon modified/GCE and a bismuth-modified GCE, N-doped carbon-modified palygorskite greatly improves the performance of GCE. Response is the best and the interfacial impedance is minimized if the fraction of carbon coating is 31%. This indicates that its performance is due to the synergies between palygorskite and N-doped carbon. Figures of merit for the modified GCE include (a) a preconcentration time of 180 s, (b) a detection limit of 0.42 μg·L⁻¹ (2σ criterion), and (c) a linear response in the 4.0 μg·L⁻¹ to 10.0 mg·L⁻¹ Pb(II) concentration range. The method is successfully applied to the determination of Pb(II) in spiked tape water and gives recoveries between 97.1 and 104.3%.

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[en] A rail-to-rail amplifier with constant transconductance, intended for audio processing, is presented. The constant transconductance is obtained by a constant current technique based on the input differential pairs operating in the weak inversion region. MOSFETs working in the weak inversion region have the advantages of low power and low distortion. The proposed rail-to-rail amplifier, fabricated in a standard 0.35 μm CMOS process, occupies a core die area of 75 x 183 μm². Measured results show that the maximum power consumption is 85.37 μW with a supply voltage of 3.3 V and the total harmonic distortion level is 1.2% at 2 kHz. (semiconductor integrated circuits)