A clock-induced-spurs detector, composed of a programmable low-pass filter (LPF), energy detector and spur detection algorithm, is presented and applied to a four-channel 1 gigabit-samples-per-second (GSPS) direct digital frequency synthesizer (DDS). The proposed detector realizes the detection of spurs based on energy-detection, and the spur detection algorithm is adopted to automatically extract the amplitude and phase of clock-induced spurs, generated by the intermodulation of harmonic spurs and multiple clocks. Finally, the extracted features are sent to auxiliary DDS to decrease the target spur, following which the detector can be turned off to save power. Additionally, the detected characteristics under different output conditions can be read out through the interface for rapid frequency switching. The proposed detector integrated into a DDS is fabricated with a 65 nm complementary metal oxide semiconductor (CMOS) process and has an area of 190 μm × 320 μm. The measured power consumption is roughly 38 mW, consuming 6% that of a single-channel DDS. The test results show that the spurious-free dynamic range (SFDR) of this DDS can be successfully enhanced from -43.1 dBc to roughly -59.9 dBc without any off-chip instruments. This effectively proves that the detection accuracy of this detector can reach around -81 dBm.
Tumor hypoxia, which is mainly caused by the inefficient microvascular systems induced by rapid tumor growth, is a common characteristic of most solid tumors and has been found to hinder treatment outcomes for many types of cancer therapeutics. In this study, an amphiphilic block copolymer, poly (ethylene glycol) methyl ether acrylate-block-n-butyl acrylate (PEGA-BA), was prepared via the ATRP method and self-assembled into core-shell micelles as nano radiosensitizers. These micelles encapsulated a photosensitizer, Chlorin e6 (Ce6), and demonstrated well-defined morphology, a uniform size distribution, and high oxygen loading capacity. Cell experiments showed that PEGA-BA@Ce6@PFCE micelles could effectively enter cells. Further in vitro anticancer studies demonstrated that the PEGA-BA@Ce6@PFCE micelles significantly suppressed the tumor cell survival rate when exposed to a laser.
A 12.5 Gbps continuous-time linear equalizer circuit (CTLE) constructed with two stage equalizer, three stages of limiting amplifier and designed in 55 nm CMOS technology for high speed serial interface of JESD204B standard is presented. Beside using degeneration RC pair to compensate low pass response of the channel and high frequency signal loss, the first equalizer also utilizes inductive shunt peaking technology to further extend the bandwidth of input signals. The proposed circuit was simulated with post layout parasitic extraction and achieves around 20 ps peak-to-peak jitter, 1.08 V voltage swing and a data rate of 12.5 Gbps through 10-inch FR-4 PCB trace with the characteristic of low equalization power consumption.
Abstract Background Meningioma is the most common intracranial tumor in the world, and total resection is the standard treatment approach. The status of meningiomas consistency is one of the most critical factors affecting the difficulty of surgery, which results in preoperative non-invasive prediction of tumor consistency is crucial for the design of surgical plan. This study aims to compare the performance of novel radiomics method and traditional apparent diffusion coefficient (ADC) values measured using regions of interest (ROI) in predicting the consistency of meningiomas. Methods and Materials: 148 patients with pathology-diagnosed meningiomas were enrolled in this retrospective study. Meningioma consistency was categorized into three grades: soft, moderate, and hard. ADC method: 3–5 ROIs (20-30mm2 each) within enhancing mass were placed on ADC to calculate the minimum, maximum, mean ADC values, and their ratios. Radiomics method: radiomics features were extracted from tumor enhancement region based on contrast-enhanced T1WI images, ADC maps, and T2WI images. Mann-Whitney U test and the least absolute shrinkage and selection operator (LASSO) algorithm were performed for potential radiomics feature selection. ADC measurement models and radiomics models were constructed separately using logistic regression. The receiver operating characteristic (ROC) and the area under curve (AUC) analysis were used to evaluate the predictive performance. Results 23 meningiomas were classified as soft, 98 were classified as moderate, and 27 as hard. For “soft” prediction, the highest AUC values for the training and validation sets are 0.54 and 0.54 respectively base on ADCmax. In contrast, AUC values were 0.82 in the training set and 0.78 in the validation set from radiomics models. For “hard” prediction, the best AUC values based on ADC measurement models were 0.58 and 0.58 respectively for the training and validation sets. The radiomics models achieved higher AUC values of 0.84 in the training set and 0.86 in the validation set. Conclusion Radiomics models outperform manual ADC measurement models in predicting meningioma consistency. Clinical Relevance Statement: Radiomics method offer better preoperative prediction of the meningioma consistency compared to manual ADC measurement methods. Therefore, the integration of artificial intelligence-based radiomics model to predict tumor consistency should be incorporated into the clinical preoperative management protocol for meningiomas.
Graphene, as a two-dimensional (2D) carbon material, has been a research focus in the field of sensors since its discovery owing to its physical and chemical properties.However, the zeroband-gap characteristic of graphene places many restrictions on its application in sensors.To expand the application potential of graphene materials in the field of detection, various surface functionalization methods have been developed.The most common and useful methods of functionalization are doping and the introduction of defects.This paper mainly reviews the state-of-the-art work on gas sensing applying defective and doped graphene.The effects of defect and heteroatom codoping on the gas-sensing properties of graphene are also discussed, and the key research directions of functionalized graphene chemical sensors in the future are proposed.
A bandgap reference circuit with voltage and current output is presented. Operational transconductance amplifier(OTA) have been used for a higher DC power supply rejection rate(PSRR) under small gate length of MOSfet. Both telescopic and folded OTA and low threshold voltage MOSfet have been used to ensure the circuit at suitable operation points under every PVT(process, source voltage and temperature) corner. Two opposite temperature coefficient resistors have been connected in series to obtain a temperature independent resistor for voltage reference's generation. This bandgap reference is implemented in a 65nm CMOS technology, occupies 0.75mm×0.67mm including bond pads, Measured results show that this circuit can operate at supply voltage from 1.1V to 1.3V, and the temperature coefficient of voltage output is 30.9ppm/ o C with 61dB PSRR (DC, 25 o C), and the temperature coefficient of current output is 51.6ppm/ o C with 69dB PSRR (DC, 25 o C), among -55 o C~125 o C without any trimming or calibration.
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