We propose a radio-over-fiber (RoF) system with 1-bit outphasing modulation. The proposed RoF system does not require a power-hungry digital-to-analog converter in access points and relaxes the ...operation speed of optical transceivers to reduce device cost. We introduce two configurations to enable 1-bit outphasing modulation in our system; mixed-signal and all-digital configurations. In the mixed-signal configuration, the effects of harmonics and phase/amplitude mismatch on the adjacent channel leakage ratio (ACLR) were analyzed through simulation, and wideband transmission with a signal bandwidth of 400 MHz was experimentally verified, complying with the 3rd Generation Partnership Project (3GPP) standard for millimeter-wave band. Moreover, wide-band transmission with a signal bandwidth of 1 GHz was also experimentally verified for beyond-5G and 6G. The all-digital configuration can be implemented in a standard digital design flow. This configuration was also verified to comply with the 3GPP standard by properly selecting the intermediate and sampling frequencies to mitigate the effects of folded harmonics and quantization noise. Finally, the proposed RoF system with both configurations has been shown to have a higher bandwidth efficiency compared with other systems complying with the 3GPP standard for the ACLR. Therefore, the proposed RoF system provides a cost-effective in-building wireless solution for 5G and 6G mobile network systems.
This article presents a low-cost and area-efficient 28-GHz CMOS phased-array beamformer chip for 5G millimeter-wave dual-polarized multiple-in-multiple-out (MIMO) (DP-MIMO) systems. A neutralized ...bi-directional technique is introduced in this work to reduce the chip area significantly. With the proposed technique, completely the same circuit chain is shared between the transmitter and receiver. To further minimize the area, an active bi-directional vector-summing phase shifter is also introduced. Area-efficient and high-resolution active phase shifting could be realized in both TX and RX modes. In measurement, the achieved saturated output power for the TX-mode beamformer is 15.1 dBm. The RX-mode noise figure is 4.2 dB at 28 GHz. To evaluate the over-the-air performance, 16 H+16 V sub-array modules are implemented in this work. Each of the sub-array modules consists of four 4 H+4 V chips. Two sub-array modules in this work are capable of scanning the beam from −50° to +50°. A saturated EIRP of 45.6 dBm is realized by 32 TX-mode beamformers. Within 1-m distance, a maximum SC-mode data rate of 15 Gb/s and the 5G new radio downlink packets transmission in 256-QAM could be supported by the module. A <inline-formula> <tex-math notation="LaTeX">2\times 2 </tex-math></inline-formula> DP-MIMO communication is also demonstrated with two 5G new radio 64-QAM uplink streams. Thanks to the proposed area-efficient bi-directional technique, the required core area for a single element-beamformer is only 0.58 mm 2 . Compact and low-cost 5G millimeter-wave MIMO systems could be realized.
Transarterial management of advance lung cancer Hori, Shinichi; Nakamura, Tatsuya; Kennoki, Norifumi ...
Japanese journal of clinical oncology,
06/2021, Letnik:
51, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Previous reports on transarterial treatment for lung cancer were reviewed. The bronchial arterial infusion therapy has a long history since 1964. Better local control with less doses of ...anti-neoplastic agents was warranted by trying transarterial administration to lung and mediastinal tumors. It is reported that both primary and metastatic tumors are fed by bronchial or other systemic arteries. The bronchial arterial embolization for hemoptysis has been introduced for clinical practice since 1973. Hemoptysis by not only benign but also malignant diseases has been well controlled by embolization. In recent decades, the technical elements for transarterial treatments have markedly improved. They make it possible to carry out precise procedures of selective catheter insertion to the tumor relating arteries. Current concepts of transarterial treatment, technical aspects and treatment outcomes are summarized. Tentative result from chemo-embolization for advanced lung cancer using recent catheter techniques was also described. It provides favorable local control and survival merits. It is considered that a population of lung cancer patients can benefit from transarterial management using small doses of anti-neoplastic agents, with less complications and less medical costs.
Gelatin sponge and polyvinyl alcohol particles have been the most popular particulate embolic agents for transarterial chemoembolization (TACE) of liver tumors. Over the last decade, calibrated ...microspheres have been introduced and increasingly used in liver tumor embolization in Western countries. In addition, drug-eluting beads (DEB) have been introduced for sustained local drug release. Such long-awaited spherical embolic agents will be introduced in Japan in the near future. The advantages of these microspheres are that particles are uniform in size and shape, and easy to inject through a microcatheter. They can travel distally to vessels corresponding to the particle size; in other words, the occlusion level can be predicted according to the particle size chosen. Thus, new bland microspheres and DEB may bring a significant advancement to embolization for primary liver tumors as well as hepatic metastases from various cancers. However, at this point, the published data suggests that both conventional TACE and DEB-TACE are equally effective for treatment of unresectable hepatocellular carcinoma, when patients are carefully selected. Therefore, indication, patient selection, and embolization techniques will be essential in order to individually adapt newer embolic agents based on oncological, anatomical and technical considerations.
Transarterial Treatment of Lung Cancer Hori, Atsushi; Dejima, Ikuo; Hori, Shinichi ...
Life (Basel, Switzerland),
07/2022, Letnik:
12, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Purpose: The treatment efficacy of the transarterial approach to lung cancer is evaluated. Materials and Methods: A total of 98 patients with advanced lung cancer or recurrent lung cancer after the ...standard therapies were enrolled retrospectively. The bronchial arteries and mediastinal branches from the subclavian artery were selected by a microcatheter. Immediately after the selective arterial infusion of anti-neoplastic agents, embolization with a spherical embolic material was carried out. Local tumor effects and overall survival were evaluated. Result: The mean reduction rate was 17.9%, with 24.2% for partial remission and with 2.1% for progression disease. The rate of stable disease was 72.6%. The response rate was 25.3%, and the disease control rate was 97.9%. The median survival time (MST) was 11.4 months, the 1-year survival rate was 45.2%, and the 2-year survival rate was 35.6%. Although it is insignificant, the MST for 51 adenocarcinomas was higher than that of 29 squamous cell carcinomas (18.6 months and 9.4 months, respectively). The local extension of tumors related to a better prognosis, though it was not significant. Lymph node metastases and distant metastases were poor prognostic factors. No major complications nor treatment-related mortalities were found in this study. Conclusion: The transarterial treatment for lung cancer should be considered as a treatment option when the other treatments were not indicated both in initial cases and in recurrent cases.
Purpose
Contrast material pooling on angiography within a tumor bed during embolization for hepatocellular carcinoma (HCC) presents as the vascular lake (VL) phenomenon. This retrospective study ...aimed to evaluate the frequency and management of VLs during chemoembolization with drug-eluting beads (DEBs) and the relationship between the VL and local response.
Materials and methods
A total of 123 HCC patients without vascular invasion or intrahepatic metastases who underwent chemoembolization with DEBs (50–100 µm superabsorbent polymer microspheres loaded with epirubicin) were enrolled. Gelatin sponge particles (GS) were injected for additional embolization in limited patients with steadily increasing size of VLs during DEB injection. Overall, 338 nodules were divided into three groups: lesions without a VL (non-VL;
n
= 250); lesions with a VL but without additional GS embolization VL–GS (−),
n
= 58; and lesions with both VL and additional GS embolization VL–GS (+);
n
= 30. The local responses were statistically compared by Fisher’s exact test with the Bonferroni correction.
Results
The frequency of VLs was 26.0 % (88/338). The response rate in the non-VL group (54.0 %) was significantly lower than those in the VL–GS (−) (91.4 %;
P
< 0.0001) and VL–GS (+) (96.7 %;
P
< 0.0001) groups.
Conclusions
VL is a common angiographic finding and might be associated with the local response.
Power amplifiers (PAs) are key components of mobile base stations. In the last decade, the power efficiency of PAs for 3G/4G mobile base stations has risen to over 50% as a result of employing ...efficiency enhancement techniques, such as Doherty, envelope tracking, and outphasing, in combination with GaN devices and digital predistortion. This trend has significantly contributed to reducing the power consumption of mobile base stations. Furthermore, digital transmitters using switch-mode PAs have the potential of breaking through the 70% efficiency level. Achieving this goal will require advances not only in circuitry but also in device technology. For active antenna systems of 5G mobile systems, ease of integration, as well as high efficiency, becomes important for PAs, and thus, Si-based devices will play a major role.
To evaluate the effect of computer-aided diagnosis (CAD) on radiologists' detection of pulmonary nodules.
Fifty chest computed tomographic (CT) examination cases were used. The mean nodule size was ...0.81 cm +/- 0.60 (SD) (range, 0.3-2.9 cm). Alternative free-response receiver operating characteristic (ROC) analysis with a continuous rating scale was used to compare the observers' performance in detecting nodules with and without use of CAD. Five board-certified radiologists and five radiology residents participated in an observer performance study. First they were asked to rate the probability of nodule presence without using CAD; then they were asked to rate the probability of nodule presence by using CAD.
For all radiologists, the mean areas under the best-fit alternative free-response ROC curves (Az) without and with CAD were 0.64 +/- 0.08 and 0.67 +/- 0.09, respectively, indicating a significant difference (P <.01). For the five board-certified radiologists, the mean Az values without and with CAD were 0.63 +/- 0.08 and 0.66 +/- 0.09, respectively, indicating a significant difference (P <.01). For the five resident radiologists, the mean Az values without and with CAD were 0.66 +/- 0.04 and 0.68 +/- 0.04, respectively, indicating a significant difference (P =.02). At observer performance analyses, there were no significant differences in Az values obtained either without (P =.61) or with (P =.88) CAD between the board-certified radiologists and the residents. For all radiologists, in the detection of pulmonary nodules 1.0 cm in diameter or smaller, the mean Az values without and with CAD were 0.60 +/- 0.11 and 0.64 +/- 0.11, respectively, indicating a significant difference (P <.01).
Use of the CAD system improved the board-certified radiologists' and residents' detection of pulmonary nodules at chest CT.
To investigate the effect of different iodine concentrations of contrast material on aortic and hepatic enhancement and the detectability of hypervascular hepatocellular carcinoma (HCC) with ...multi-detector row computed tomography (CT) and a uniphasic contrast material injection technique.
Two hundred one patients with known or who were suspected of having HCC underwent multi-detector row CT; 58 patients with hypervascular HCC were identified. First-, second-, and third-phase scanning was started with the aortic arrival times plus 15 seconds, plus 30 seconds, and plus 105 seconds, respectively. All patients were assigned randomly into two groups. Patients in groups A and B received iopamidol with an iodine concentration of 300 mg/mL and 370 mg/mL, respectively, with the same total iodine load per patient per body weight. The liver and aorta enhancement and tumor-to-liver contrast (TLC) were measured. Depiction of hepatic arteries was evaluated visually by two radiologists.
During the first phase, aortic enhancement was significantly (P <.01) higher in group B, with no significant difference in hepatic enhancement between the two groups. During the second phase, aortic enhancement was significantly (P <.01) higher in group A, with no significant difference in hepatic enhancement. The TLC was significantly (P <.01) higher in group B during the first phase, but there was no significant difference between the two groups during the second phase. There was no significant difference in any parameters between the two groups during the third phase. Depiction of the hepatic arteries in group B was significantly (P <.05) superior to that in group A.
In the arterial phase, administration of a higher concentration of contrast material is effective for a significantly higher TLC.
5G NR service will provide extremely-high-speed mobile data access using the millimeter-wave spectrum. To further boost the data-rate and spectrum efficiency, dual-polarized MIMO (DP-MIMO) will be ...introduced 1-4. Separated beamformer arrays will be required for H and V polarizations. However, the increased free-space-path-loss for the 5G NR band n257 (26.5GHz to 29.5GHz) demands numerous elements to cover enough communication distance. Concerning the required considerable number of chips, an area-efficient design will be necessary for a DP-MIMO system targeting 5G NR FR2. This paper presents a 28GHz 4\mathrm {H} +4\mathrm {V} bi-directional beamformer chip supporting DP-MIMO in 65nm CMOS. The proposed neutralized bi-directional amplifier significantly reduces the required on-chip area. A bi-directional vector-summing phase shifter is also introduced. The measured RMS phase and gain errors are 0.4° and 0.2dB at 28GHz, respectively. The array module achieves a saturated EIRP of 45.6dBm/pol. at 0° scan with a 32\mathrm {H} +32\mathrm {V} array. In a 1m OTA measurement, a 4 \times 4 sub-array module supports single-carrier data-rates of 15Gb/s and 6.4Gb/s per polarization in 64QAM and 256QAM, respectively. The measured 400MHz OFDMA TX-to-RX EVM for the 4 \times 4 sub-array module at 0° scan is -34.4dB in 256QAM. 2 \times 2 DP-MIMO communication with a 400MHz 5G NR channel bandwidth is also achieved with a 64-QAM EVM of 4.9% for the 4\times 4 sub-array module.
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