Vitamin E as a Treatment for Nonalcoholic Fatty Liver Disease: Reality or Myth?

Obesity is one of the major epidemics of this millennium, and its incidence is growing worldwide. Following the epidemics of obesity, nonalcoholic fatty liver disease (NAFLD) has become a disease of increasing prevalence and a leading cause of morbidity and mortality closely related to cardiovascular disease, malignancies, and cirrhosis. It is believed that oxidative stress is a main player in the development and progression of NAFLD. Currently, a pharmacological approach has become necessary in NAFLD because of a failure to modify lifestyle and dietary habits in most patients. Vitamin E is a potent antioxidant that has been shown to reduce oxidative stress in NAFLD. This review summarizes the biological activities of vitamin E, with a primary focus on its therapeutic efficacy in NAFLD

SGLT2 Inhibitors and the Diabetic Kidney

Diabetic nephropathy (DN) is the most common cause of end-stage renal disease worldwide. Blood glucose and blood pressure control reduce the risk of developing this complication; however, once DN is established, it is only possible to slow progression. Sodium-glucose cotransporter 2 (SGLT2) inhibitors, the most recent glucose-lowering oral agents, may have the potential to exert nephroprotection not only through improving glycemic control but also through glucose-independent effects, such as blood pressure-lowering and direct renal effects. It is important to consider, however, that in patients with impaired renal function, given their mode of action, SGLT2 inhibitors are less effective in lowering blood glucose. In patients with high cardiovascular risk, the SGLT2 inhibitor empagliflozin lowered the rate of cardiovascular events, especially cardiovascular death, and substantially reduced important renal outcomes. Such benefits on DN could derive from effects beyond glycemia. Glomerular hyperfiltration is a potential risk factor for DN. In addition to the activation of the renin-angiotensin-aldosterone system, renal tubular factors, including SGLT2, contribute to glomerular hyperfiltration in diabetes. SGLT2 inhibitors reduce sodium reabsorption in the proximal tubule, causing, through tubuloglomerular feedback, afferent arteriole vasoconstriction and reduction in hyperfiltration. Experimental studies showed that SGLT2 inhibitors reduced hyperfiltration and decreased inflammatory and fibrotic responses of proximal tubular cells. SGLT2 inhibitors reduced glomerular hyperfiltration in patients with type 1 diabetes, and in patients with type 2 diabetes, they caused transient acute reductions in glomerular filtration rate, followed by a progressive recovery and stabilization of renal function. Interestingly, recent studies consistently demonstrated a reduction in albuminuria. Although these data are promising, only dedicated renal outcome trials will clarify whether SGLT2 inhibitors, in addition to their glycemic and blood pressure benefits, may provide nephroprotective effects

Investigation of Evaporator Performance with and without Liquid Overfeeding

In the present work, the performance of a segmentally baffled shell-and-tube evaporator working with liquid overfeeding is investigated. The refrigerant is R134a that flows inside the tubes, while water flows on the shell side. A single shell pass has been adopted for the water with one tube pass for the evaporating fluid. The test rig used for the experimental measurements consists of a primary refrigerant loop plus the condenser and the evaporator water auxiliary loops. The evaporator can be fed with two-phase mixture from the expansion valve or with saturated liquid coming from the liquid-vapor separator (in this case a variable speed recirculation pump is used). Inlet and outlet temperatures have been measured for both fluids together with the flow rate allowing the determination of the overall heat transfer coefficient. In addition, pressure drop have been measured on the refrigerant side. Tests have been performed both without overfeeding and with overfeeding at different values of recirculation ratio. The recirculation ratio is defined as the ratio between refrigerant flow rate at the evaporator and the vaporized refrigerant flow rate. Furthermore, measurements have been taken at fixed water outlet temperature and varying the heat duty. In order to study the evaporator behavior, a computational procedure has been developed. Finally, the numerical model of the heat exchanger has been validated against experimental data

Obesity, Male Reproductive Function and Bariatric Surgery

Overweight and obesity are associated with several chronic complications, such as type 2 diabetes, arterial hypertension and atherosclerotic cardiovascular diseases, with relevant consequences for patients and public health systems. Reproductive function abnormalities, such as obesity-related secondary hypogonadism, erectile dysfunction and infertility, represent other abnormalities negatively affecting the quality of life of men suffering from obesity but, despite their high prevalence, these are often understated because of a general lack of awareness in clinical practice. Obesity and gonadal function are closely related, with obesity being associated with hypogonadism that is reversed by body weight reduction thus ameliorating reproductive and sexual health. Clinical studies specifically evaluating the impact of non-surgical weight loss on testosterone levels sometimes showed conflicting results, whereas extensive literature has demonstrated that weight loss after bariatric surgery is correlated with an increase in testosterone levels greater than that obtained with only lifestyle interventions, suggesting the role of surgery also for the treatment of hypogonadism in obese male. However, studies concerning the consequences of bariatric surgery on overall reproductive function in the male, including also sexual activity and fertility, are limited and data regarding long-term effects are lacking. Here we present a brief review summarizing the evidence regarding the interplay between obesity and reproductive abnormalities in the obese male, together with the role of bariatric surgery for the treatment of these complications, describing both the positive effects and the limitations of this procedure

Innovative Minichannel Condensers and Evaporators for Air Conditioning Equipment

The use of aluminum heat exchangers for refrigeration and air-conditioning equipment is very interesting since it allows to reduce weight and manufacturing costs while maintaining high performance. In this paper a two-phase heat transfer characterization of an innovative aluminum minichannel heat exchanger is presented. The heat exchanger (HX) is composed by rectangular channels with internal perforated turbolators. A special test section has been projected and realized in the Two Phase Heat Transfer Lab of the University of Padova in order to measure the heat transfer coefficient (HTC) on the refrigerant side during flow boiling and condensation. The test section has a single refrigerant channel with a perforated fin to make the minichannels. The test section is provided with 14 water flow modules installed at top and bottom of the refrigerant channel to promote boiling or condensation of the refrigerant. Therefore, the test section is made of seven different zones: each of them is equipped with 8 thermocouples to measure the wall temperature during the refrigerant phase change. The heat flow rate in each zone is calculated by an energy balance on the water side. Pressure transducers and thermocouples on the refrigerant side allow to determine the saturation temperature and thus the heat transfer coefficient of the refrigerant. The operating refrigerant used during tests is R410A. The particular scheme adopted for the test section enables to measure HTC at varying vapor quality and heat flow rate. Vaporization and condensation tests were carried out with different saturation temperatures, specific heat flow rate (from 40 to 150 kW/m2) and refrigerant mass flux (50÷150 kg/(m2 s) ). Data acquired have been compared with vaporization and condensation predictions from various correlations available in literature. This part of the work is very interesting since no data is available in the literature for such a geometry in vaporization nor in condensation. Therefore, the present paper will investigate the potential performance of these innovative minichannel heat exchangers as condensers and evaporators in air-conditioning equipment

Relationship between Heart Disease and Liver Disease: A Two-Way Street

In clinical practice, combined heart and liver dysfunctions coexist in the setting of the main heart and liver diseases because of complex cardiohepatic interactions. It is becoming increasingly crucial to identify these interactions between heart and liver in order to ensure an effective management of patients with heart or liver disease to provide an improvement in overall prognosis and therapy. In this review, we aim to summarize the cross-talk between heart and liver in the setting of the main pathologic conditions affecting these organs. Accordingly, we present the clinical manifestation, biochemical profiles, and histological findings of cardiogenic ischemic hepatitis and congestive hepatopathy due to acute and chronic heart failure, respectively. In addition, we discuss the main features of cardiac dysfunction in the setting of liver cirrhosis, nonalcoholic fatty liver disease, and those following liver transplantation

Deep seated gravitational slope deformation effects on Quaternary deposits in the Western Alps (NW Italy )

Deep-seated gravitational slope deformations (DSGSDs) are well-known to affect the landscape and the morphology of Alpine valleys. In contrast, little is known on their influence on Quaternary deposits. This paper, focused on the Western Italian Alps, aims to fill this gap. Eight case studies, identified after a long term field experience, are presented, representative of different geological settings. To fully define their distinctive features, such sites have been characterized using various methods: geological surveys, geophysics and geomatic techniques. DSGSD proved to influence the sediment deposition primarily with the continuous supply of centimetric/decimetric angular clasts. This have different consequences on sediments, depending on their features, in some cases deeply modifying their typical facies (i.e., glacial, colluvial and lacustrine sediments), whilst in other cases their influence is less evident (i.e., debris, avalanche and torrential deposits). This paper can be a useful tool when dealing with DSGSD-related deposits, helping avoid misinterpretations

Analytical solution of the coupled advection-diffusion and navier-stokes equation for air pollutant emission simulation

This work presents a model where the Navier-Stokes equation is coupled to the advection-diffusion equation. The decomposition method is applied to the two-dimensional non-stationary Navier-Stokes equation and Duhamel’s Principle is used to obtain a series approximation of the solution. The concentration is represented by the Gaussian dispersion model, assuming constant diffusion coefficients

Association of fat mass profile with natriuretic peptide receptor alpha in subcutaneous adipose tissue of medication-free healthy men: A cross-sectional study

Background: Atrial natriuretic peptide increases lipolysis in human adipocytes by binding to natriuretic peptide receptor-A (NPRA). The aim of the current study was to examine the associations of NPRA mRNA of subcutaneous adipose tissue with fat mass, fat-free mass, body mass index (BMI) and arterial blood pressure in medication-free healthy men. Method: Thirty-two volunteers [age (years): 36.06±7.36, BMI: 27.60±4.63 (kg/m2)] underwent assessments of body height/weight, % fat mass, fat-free mass (kg), blood pressure, and a subcutaneous adipose tissue biopsy via a surgical technique. Results: We found that NPRA mRNA was negatively associated with % fat mass (r=-0.40, R2=0.16, p=0.03) and BMI (r=-0.45, R2=0.20, p=0.01). Cohen’s f2 effect size analyses showed a small effect size between NPRA mRNA and BMI (f2=0.25). One-way analysis of variance with Bonferroni post-hoc tests showed a tendency for mean differences of NPRA mRNA across BMI categories (p=0.06). This was confirmed by Cohen’s d effect size analyses revealing a large effect size of NPRA mRNA between obese individuals (BMI≥30 kg/m2) and either normal weight (BMI=19-25 kg/m2; d=0.94) or overweight (BMI=25-30 kg/m2; d=1.12) individuals. Conclusions: NPRA mRNA is negatively associated with % fat mass and BMI in medication-free healthy men, suggesting a possible role of NPRA in the control of fat mass accumulatio