On the performance of a mixed RF/MIMO FSO variable gain dual-hop transmission system

In this work, we propose a mixed radio frequency (RF) and multiple-input-multiple-output (MIMO) free-space optical (FSO) system based on a variable-gain dual-hop relay transmission scheme. The RF channel is modeled by Rayleigh distribution and Gamma–Gamma turbulence distribution is adopted for the MIMO FSO link, which accounts for the equal gain combining diversity technique. Moreover, new closed-form mathematical formulas are obtained including the cumulative distribution function, probability density function, moment generating function, and moments of equivalent signal-to-noise ratio of the dual-hop relay system based on Meijer’s G function. As such, we derive the novel analytical expressions of the outage probability, the higher-order fading, and the average bit error rate for a range of modulations in terms of Meijer’s G function. Furthermore, the exact closed-form formula of the ergodic capacity is derived based on the bivariate Meijer’s G function. The evaluation and simulation are provided for system performance, and the effect of spatial diversity technique is discussed as well

Determination of Groundwater Recharge Mechanism Based on Environmental Isotopes in Chahannur Basin

In recent years, the lake area of the Chahannur Basin has been decreasing, leading to an increase in salt dust storms. In order to find out the recharge mechanism of groundwater in the Chahannur Basin, a total of 51 groundwater and surface water samples were collected. Tritium (3H) isotope and Freon (CFCs) were used to estimate the age of groundwater and preliminarily analyze the sources of groundwater recharge. The characteristics of hydrogen, oxygen, and strontium isotopes are used to indicate the characteristics of the water cycle in the Chahannur Basin. The results show that: (1) Two dating methods, tritium isotope (3H) and Freon (CFCs), are suitable for semi-quantitative dating of groundwater in the Chahannur Basin. (2) Hydrogen, oxygen, and strontium isotopes can be used to characterize the groundwater cycle in the Chahannur Basin. (3) The groundwater level around the Chahannur Lake area is low, and the groundwater in the Chahannur Basin flows from the southwest and northwest to the lake area. (4) The groundwater in the Chahannur Basin is mainly replenished by atmospheric precipitation, and the evaporation of groundwater and surface water is strong. The research results provide a basis for the study of measures to prevent the reduction in the Chahannur watershed area

Clinical characteristics and outcomes of Chinese patients with coronary heart disease and resistant hypertension

Abstract There is currently few research on clinical characteristics and outcomes of coronary heart disease (CHD) with resistant hypertension in central region of China. This study aimed to assess the risk factors and outcomes of CHD and resistant hypertension in population of central region of China. A total of 1467 CHD patients with hypertension were included and considered to three groups according to blood pressure control: controlled group (blood pressure < 140/90 mmHg on three or less antihypertensive drugs); uncontrolled group (blood pressure ≥ 140/90 mmHg on two or less antihypertensive drugs); or resistant group (blood pressure ≥ 140/90 mmHg on three antihypertensive drugs or < 140/90 mmHg on at least four antihypertensive drugs including diuretic). The authors evaluated the clinical outcomes of three groups at 1‐year follow‐up. The prevalence of resistant hypertension was 21.8%. Significant adjusted associated factors of resistant hypertension included per unit changes body mass index (BMI, OR 1.12), and four categorical variable diagnosis by yes or no: heart failure (HF, OR 2.62), left ventricular hypertrophy (LVH, OR 2.83), diabetes (OR 1.55), and chronic kidney disease (CKD, OR 1.63). In multiple adjusted Cox regression analysis, patients in resistant group had a higher risk of the primary outcome (HR, 2.14 [95% CI, 1.47–3.11]; p < .001). Moreover, the risk of atherosclerotic cardiovascular disease (ASCVD) in patients with resistant hypertension is also significantly increased (HR, 2.11 [95% CI, 1.39–3.20]; p < .001). In conclusion, resistant hypertension was a quite common and high proportion finding in patients with CHD and hypertension in central region of China, and these patients have a worse clinical prognosis

Thirty‐six‐month results of laparoscopic‐based renal denervation plus unilateral laparoscopic adrenalectomy for the treatment of patients with resistant hypertension caused by unilateral aldosterone‐producing adenoma

Abstract The aim of this study was to explore the long‐term clinical results of Renal denervation (RDN) from the adventitia of the renal artery plus unilateral laparoscopic adrenalectomy to treat patients with resistant hypertension caused by unilateral aldosterone‐producing adenoma (APA). Sixty patients with resistant hypertension caused by APA who were treated at Henan Provincial People's Hospital from December 2016 to March 2018 were selected and randomly assigned to undergo RDN from the adventitia of the renal artery plus adrenalectomy (RDN group, n = 30) or adrenalectomy alone (control group, n = 30). Office blood pressure (BP), antihypertensive medication usage and other laboratory characteristics were followed every 6 months through 36 months. Follow‐up data were available at 36 months for 23 of 30 subjects in the RDN group and for 21 of 30 subjects who were in the control group. At 36 months postprocedure, the reduction in the RDN group was 42.2 ± 21.6 mmHg and that in the control group was 29.8 ± 13.5 mmHg (p = .029 between the groups). During the follow‐up to 36 months postprocedure, no patients in either the RDN group or the control group died due to surgical complications, and the RDN group had no procedural complications, including renal artery dissection, perforation, and renal artery stenosis. There was no change in the mean eGFR of the two groups, and no serious adverse events were reported. In conclusion, RDN from the adventitia of the renal artery plus unilateral laparoscopic adrenalectomy resulted in sustained lowering of BP at 3 years in a selected population of subjects with resistant hypertension caused by unilateral APA without serious safety concerns