A feasibility study of the measurement of Higgs pair creation at a Photon Linear Collider

We studied the feasibility of the measurement of Higgs pair creation at a Photon Linear Collider (PLC). From the sensitivity to the anomalous self-coupling of the Higgs boson, the optimum $\gamma \gamma$ collision energy was found to be around 270 GeV for a Higgs mass of 120 GeV/$c^2$. We found that large backgrounds such as $\gamma \gamma \rightarrow W^+W^-, ZZ,$ and $b\bar{b}b\bar{b}$, can be suppressed if correct assignment of tracks to parent partons is achieved and Higgs pair events can be observed with a statistical significance of $\sim 5 \sigma$ by operating the PLC for 5 years.Comment: 7 pages, 8 figures, 5 table

Blood pressure in heart failure management and prevention

Hypertension is a leading cause of heart failure and other cardiovascular diseases. Its role in the pathogenesis of heart failure with reduced ejection fraction (HFrEF) differs from that in heart failure with preserved ejection fraction (HFpEF). Moreover, rigorous blood pressure control may reduce the incidence of heart failure. However, once heart failure develops, prognosis is affected by blood pressure, which may differ between patients with and without heart failure. Therefore, the association between guideline-directed medical therapy (GDMT) for heart failure and its uptitration must be considered for blood pressure management and should not be overlooked. Heart failure medications affect the blood pressure and efficacy per baseline blood pressure value. This review discusses the potential mechanisms by which hypertension leads to HFrEF or HFpEF, the impact of hypertension on incident heart failure, and the recommended approaches for blood pressure management in patients with heart failure. </p

Evaluation of calibration factor of OSLD toward eye lens exposure dose measurement of medical staff during IVR

The eye lens is a sensitive organ of which an x‐ray exposure dose should be managed during interventional radiology (IVR). In the actual situations, the eye lens is exposed to scattered x‐rays; they have different from the standard x‐ray energies which are used for general dose calibration of the dosimeter. To perform precise dose measurement, the energy dependence of the dosimeter should be properly accounted for when calibrating the dosimeter. The vendor supplies a calibration factor using 80‐kV diagnostic x‐rays under a free‐air condition. However, whether it is possible to use this calibration factor to evaluate the air kerma during the evaluation of the eye lens dose is unclear. In this paper, we aim to precisely determine calibration factors, and also examine the possible application of using a vendor‐supplied calibration factor. First, the x‐ray spectrum at the eye lens position during fluoroscopy was measured with a CdTe x‐ray spectrometer. We mimicked transfemoral cardiac catheterization using a human‐type phantom. Second, we evaluated the doses and calibration factors at three dosimetric points: front and back of protective goggles, and the front of the head (eye lens position). We used the measured x‐ray spectrum to determine the incident photon distribution in the eye lens regions, and x‐ray spectra corresponding to the dosimetric points around the eye lens were estimated using Monte Carlo simulation. Although the calibration factors varied with dosimetric positions, we found that the factors obtained were similar to the vendor‐supplied calibration factor. Furthermore, based on the experiment, we propose a practical way to calibrate an OSL dosimeter in an actual clinical situation. A person evaluating doses can use a vendor‐supplied calibration factor without any corrections for energy dependences, only when they add a systematic uncertainty of 5%. This evidence will strongly support actual exposure dose measurement during a clinical study

Cbl-b Positively Regulates Btk-mediated Activation of Phospholipase C-γ2 in B Cells

Genetic studies have revealed that Cbl-b plays a negative role in the antigen receptor–mediated proliferation of lymphocytes. However, we show that Cbl-b–deficient DT40 B cells display reduced phospholipase C (PLC)-γ2 activation and Ca2+ mobilization upon B cell receptor (BCR) stimulation. In addition, the overexpression of Cbl-b in WEHI-231 mouse B cells resulted in the augmentation of BCR-induced Ca2+ mobilization. Cbl-b interacted with PLC-γ2 and helped the association of PLC-γ2 with Bruton's tyrosine kinase (Btk), as well as B cell linker protein (BLNK). Cbl-b was indispensable for Btk-dependent sustained increase in intracellular Ca2+. Both NH2-terminal tyrosine kinase-binding domain and COOH-terminal half region of Cbl-b were essential for its association with PLC-γ2 and the regulation of Ca2+ mobilization. These results demonstrate that Cbl-b positively regulates BCR-mediated Ca2+ signaling, most likely by influencing the Btk/BLNK/PLC-γ2 complex formation