RESUMO
Background: Human epidermal growth factor receptor 2 (HER2) inhibitors play a vital role in the treatment of HER2-positive breast cancer. Numerous studies have shown that traditional HER2 inhibitors and chemotherapeutics such as albumin-paclitaxel, liposomal doxorubicin, and cyclophosphamide (TAC regimen) have different degrees of cardiotoxicity. Pyrotinib is a novel small-molecule HER2 inhibitor and has no cardiotoxicity. Here, the purpose of this study was to investigate the cardiac safety of pyrotinib with TAC regimen for HER2-positive breast cancer. Methods: In this study, 22 patients with stage I-IIIA HER2-positive breast cancer were screened, enrolled, and assigned to receive either neoadjuvant or postoperative adjuvant treatment with pyrotinib (320-400 mg, once daily) combined with TAC (albumin-paclitaxel 260 mg/m2, liposomal doxorubicin 20 mg/m2, cyclophosphamide 600 mg/m2) from December 2019 to May 2021. Patients' heart function was monitored using electrocardiogram, echocardiogram, and serological indicators. ST segment and T wave change, left ventricular ejection fraction (LVEF, %), N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), creatine kinase (CK), creatine kinase myoglobin band (CK-MB), together with patients' weight, white blood cells (WBC), red blood cells (RBC), platelets, plasma lipid, and glucose were recorded. Results: Before and after the 2nd, 4th, and 6th cycles of treatment, the incidence of abnormal electrocardiogram of patients enrolled in the neoadjuvant treatment group was 36.4%, 27.3%, 27.3%, and 27.3%, respectively, while in the postoperative adjuvant treatment, the incidence was 45.5%, 36.4%, 36.4%, and 36.4%, respectively. LVEF before and after treatment in the neoadjuvant chemotherapy group was 65.36%±2.25% and 65.00%±2.15% (t=1.305, P=0.221), while in the postoperative adjuvant treatment group, LVEF was 66.27%±2.69% and 65.18%±1.89% (t=1.359, P=0.204). Pyrotinib combined with a TAC regimen may have induced a decrease in RBC. No obvious abnormality was found in the level of NT-pro-BNP, CK, CK-MB, patients' weight, WBC, platelets, plasma lipid, or glucose in all enrolled patients during the entire treatment process. Conclusions: Our findings indicated that neither neoadjuvant nor postoperative adjuvant treatment using pyrotinib combined with a TAC regimen to treat patients with HER2-positive breast cancer increased cardiotoxicity. However, the treatment may have induced a decrease in RBC and further research is needed.
RESUMO
A carbon dioxide (CO2) sensor is developed using quartz enhanced photoacoustic spectroscopy (QEPAS) with a 2.0 µm distributed feedback diode laser. The detection is based on a 2f wavelength-modulation spectroscopy approach by dithering and scanning the laser current. The laser modulation depth is optimized at normal atmosphere pressure and room temperature. The influence of the H2O presence in the sample gas mixture on the CO2 sensor performance is also investigated. The results show that, with 1% CO2 concentration, the H2O in the concentration ranges of 0 to 0.2% has an effect on the CO2 signal amplitude and phase, and the largest amplitude difference is ~2.1 times. When the H2O concentration is over 0.2%, the CO2 signal amplitude is saturated and remains steady. Atmospheric CO2 concentration is well measured using the optimal sensor parameters. Benefiting from the strong absorption line intensity at 4989.97 cm(-1), a detection limit of 19 ppm (1σ, 300 ms averaging time) is achieved, which corresponds to a normalized noise equivalent absorption coefficient of 4.71 × 10(-9) cm(-1) · W · Hz(-1/2).
RESUMO
The present paper studied the impact of geometry dimensions, located angle and detection position of a quartz tuning fork (QTF) on the sensitivity of QEPAS system. Ten kinds of QTFs were employed to compare the sensitivity with each other, and the results show that the QTF with a wedge-shape top obtains a higher quality factor and turns to be 50% more sensitive than the ones with a regular cuboid top when detecting the water concentration at 7 306 cm-1. By studying the located angle of a QTF, it was found that it nearly makes no difference, but more noise is introduced when there is an angle phi between the laser beam and QTF. The optimal detection position of a QTF appears to be 3. 1 cm away from the bottom of the QTF under the case of the normal incidence. At last the influence of external contamination on the resonant frequency of a QTF is discussed. The authors found that the frequency of the QTF decreases along with the contamination increasing. A novel method to lower the frequency of the QTF is proposed. This may make a contribution to the QEPAS used in detecting trace gas with a low V-T relaxation.
