Background Radiotherapy-associated secondary cancer is an important issue for the treatment of breast cancer (BCa). This study aimed to investigate the molecular mechanism and genetic risk factors for radiation-associated secondary diseases in BCa. Methods The differentially expressed genes (DEGs) between preradiation and postradiation BCa samples in the GSE65505 dataset were obtained. The pathways related to the radiation-associated DEGs in the protein–protein interaction (PPI) network modules were identified. miRNAs targeted to the key genes in the PPI network were identified, and their association with BCa prognosis was analyzed. Results A total of 136 radiation-associated DEGs preradiation and postradiation BCa samples were screened out. The PPI network consisted of a significant module that consisted of 21 upregulated DEGs that were associated with “hsa04512: ECM–receptor interaction,” “hsa04151: PI3K-Akt signaling pathway,” and “hsa04115: p53 signaling pathway.” Sixteen DEGs, including three collagen genes collagen type I alpha 1 chain (COL1A1), COL3A1, and COL1A2, were enriched in 17 radiation-associated pathways. The three genes were upregulated in BCa tissues compared with controls and were also elevated by radiation. They were targeted by hsa-miR-29a/c, and the expression levels of hsa-miR-29a/c were associated with a poor prognosis of BCa. Conclusions The upregulation of COL1A1, COL3A1, and COL1A2 might be genetic risk factors for radiation-associated secondary diseases in BCa.

This paper presents a wireless and passive micro pressure system based on the LC mutual inductance detection mechanism for gastrointestinal (GI) pressure monitoring. The micro pressure system is composed of a sensor capsule (a pressure sensitive micro capacitive sensor in series with an induction coil to form an LC tank) and a detection unit (a detection coil connected with a network analyzer). The pressure variations under measurement lead to changes in the capacitance of the pressure sensor and therefore a shift in the LC tank resonant frequency, quantified by the impedance measurement of the detection coil. The pressure sensor was fabricated using microfabrication processes with key parameters optimized. The in vitro characterization of the micro pressure system recorded a sensitivity of 0.2491 kHz/kPa (-10 kPa to 30 kPa). One-month rabbit stomach pressure monitoring was conducted based on the developed micro pressure system as a confirmation of device long term in vivo stability. Furthermore, rabbit stomach pressure variations before and after food feeding was recorded and compared where three distinctive contraction patterns (random contraction with low amplitude, irregular strong contractions and regular contraction in a cyclic manner) following food feeding were located. Compared to previous reported GI pressure sensors, this LC tank is featured with simple device structure without batteries and electrical components for energy transfer. Both in vitro and in vivo characterization confirm the functionality of the system, which may enable the gastrointestinal motility study in the near future.

A readout circuit is presented for wireless passive LC sensors, where an inductor–capacitor (LC) resonant circuit was combined with a readout coil for resonant frequency detection. The impedance phase of the readout coil shows a ‘dip’ near the sensor’s resonant frequency due to the mutual inductance. Previously, the phase-dip has suffered from limited amplitude in the low-coupling-coefficient condition (especially in the case of implantation), rendering portable detection troublesome. To address this issue, in this study a new differential transduction circuit was proposed where both theoretical analysis and numerical simulations were performed. Compared to conventional transduction circuits (e.g., the I–V circuit and the auto-balancing bridge circuit), the differential circuit was more sensitive to the phase change, enabling more reliable and precise resonant frequency detection. Moreover, the proposed readout circuit was used to detect the gastrointestinal pressure of rabbits with a Ø10 mm × 14 mm LC pressure sensor at an operational distance of up to 60 mm between the LC sensor and the readout circuit. Experimental results recorded a measurement resolution lower than 0.4 kPa and a measurement speed of eight times per second.