Greater Elevation Research Articles

Invasion and high-elevation acclimation of the red imported fire ant, Solenopsis invicta, in the southern Blue Ridge Escarpment region of North America.

The red imported fire ant (Solenopsis invicta) is a non-native invasive species that rapidly spread northward in the United States after its introduction from South America in the 1930s. Researchers predicted that the northward spread of this invasive ant would be limited by cold temperatures with increased latitude and greater elevation in the Blue Ridge Escarpment region of the United States. The presence of S. invicta at relatively high elevations north of their projected limits suggests greater cold tolerance than previously predicted; however, these populations might be ephemeral indications of strong dispersal abilities. In this study, we investigated potential physiological adaptations of S. invicta that would indicate acclimation to high elevation environments. We hypothesized that if S. invicta colonies can persist in colder climates than where they originated, we would find gradients in S. invicta worker cold tolerance along a montane elevational gradient. We also predicted that higher elevation S. invicta ants might incur greater physiological costs to persist in the colder climate, so we measured colony lipid content to assess health status. For comparison, we also collected physiological temperature tolerance data for the co-occurring dominant native woodland ant Aphaenogaster picea. We found that S. invicta occurring at higher elevations exhibited greater physiological tolerance for cold temperatures as compared to lower-elevation conspecifics-a cold tolerance pattern that paralleled of the native A. picea ants along the same gradient. Both S. invicta and A. picea similarly exhibited lower thermal tolerances for colder temperatures when moving up the elevational gradient, with A. picea consistently exhibiting a lower thermal tolerance overall. There was no change in S. invicta colony lipid content with elevation, suggesting that greater metabolic rates were not needed to sustain these ants at high elevations.

Changes in Blood Glucose Level After Steroid Injection for Musculoskeletal Pain in Patients With Diabetes.

ObjectiveTo investigate changes in blood glucose level after steroid injection in patients with type 2 diabetes mellitus (DM) and factors affecting those changes.MethodsWe retrospectively studied 51 patients with type 2 DM who underwent steroid injection for shoulder and back pain. Mean fasting blood sugar (FBS) levels for 7 days before steroid injection was used as the baseline blood glucose level, which was compared with FBS levels for 14 days after steroid injection. We compared the differences in blood glucose changes between HbA1c >7% and HbA1c ≤7% groups and those between insulin and non-insulin treated groups. Demographic data, injection site, and steroid dose were analyzed.ResultsCompared to baseline, blood glucose significantly (p=0.012) elevated 1 day after steroid injection but not 2 days after injection. In the HbA1c >7% and insulin groups, blood glucose was significantly increased 1 day after injection compared to that in the HbA1c ≤7% (p=0.011) and non-insulin (p=0.024) groups, respectively. Higher HbA1c level before injection was significantly (p=0.003) associated with the degree of blood glucose increase 1 day after injection. No significant differences were noted in the degree of blood glucose increase according to injection site or steroid dose.ConclusionHigher HbA1c level was associated with greater elevation in blood glucose 1 day after steroid injection. Careful monitoring of blood glucose is required on the first day after steroid injection in patients with poorly controlled DM.

Penetrating Traumatic Brain Injury Triggers Dysregulation of Cathepsin B Protein Levels Independent of Cysteine Protease Activity in Brain and Cerebral Spinal Fluid.

Cathepsin B (CatB), a lysosomal cysteine protease, is important to brain function and may have dual utility as a peripheral biomarker of moderate-severe traumatic brain injury (TBI). The present study determined levels of pro- and mature (mat) CatB protein as well as cysteine protease activity within the frontal cortex (FC; proximal injury site), hippocampus (HC; distal injury site), and cerebral spinal fluid (CSF) collected 1-7 days after craniotomy and penetrating ballistic-like brain injury (PBBI) in rats. Values were compared with naïve controls. Further, the utility of CatB protein as a translational biomarker was determined in CSF derived from patients with severe TBI. Craniotomy increased matCatB levels in the FC and HC, and led to elevation of HC activity at day 7. PBBI caused an even greater elevation in matCatB within the FC and HC within 3-7 days. After PBBI, cysteine protease activity peaked at 3 days in the FC and was elevated at 1 day and 7 days, but not 3 days, in the HC. In rat CSF, proCatB, matCatB, and cysteine protease activity peaked at 3 days after craniotomy and PBBI. Addition of CA-074, a CatB-specific inhibitor, confirmed that protease activity was due to active matCatB in rat brain tissues and CSF at all time-points. In patients, CatB protein was detectable from 6 h through 10 days after TBI. Notably, CatB levels were significantly higher in CSF collected within 3 days after TBI compared with non-TBI controls. Collectively, this work indicates that CatB and its cysteine protease activity may serve as collective molecular signatures of TBI progression that differentially vary within both proximal and distal brain regions. CatB and its protease activity may have utility as a surrogate, translational biomarker of acute-subacute TBI.

Blunted Autophagy and Heat Shock Responses in Peripheral Blood Mononuclear Cells of Elderly Adults During Prolonged, Extreme‐Heat Exposure

With rising global temperatures and accompanying increases in the incidence and severity of extreme heat events, there are growing concerns about the impact of heat stress on human health. Increases in the activation of autophagy and the heat shock response are essential to cellular survival under stressful conditions, such as extreme heat. Accumulating evidence from various animal models suggests an age‐related decline in the autophagy and heat shock response pathways during heat stress; however, this has not yet been assessed in humans. We therefore sought to evaluate the hypothesis that the autophagy and heat shock response would be blunted in elderly compared to young adults following a prolonged heat exposure. To assess this hypothesis, peripheral blood mononuclear cells (PBMCs) were harvested from 10 young (23 [SD 3] years; 3 women) and 9 elderly adults (71 [SD 3] years; 2 women) prior to and following 9‐hours of resting exposure to extreme heat (40°C, ~15% relative humidity). Changes in microtubule associated protein 1 light chain 3 beta (LC3)‐II (indicative of autophagy) and heat shock protein 70 were analysed via Western blot, while their associated genes (LC3B and HSPA1A, respectively) were measured via quantitative reverse transcription polymerase chain reaction. All values were normalized to β‐actin and reported as fold changes relative to baseline. Core temperature (indexed by rectal temperature) was measured throughout the exposure. Data are presented as means and standard deviations (SD) and were compared between‐groups using unpaired (2 tailed) t‐tests (α=0.05). After 9‐h of heat exposure, the elevation in core temperature from baseline values were greater in the older (1.0°C [SD 0.3]) vs. young adults (0.6°C [SD 0.2]; p<0.01). Despite this, LC3‐II protein was lower in elderly (2.02 [SD 2.00]) when compared to young adults (4.45 [SD 5.93]; p=0.04). This was further revealed by a reduction in LC3B gene expression in elderly (1.39 [SD 0.39]) compared to young (2.57 [SD 3.78]; p=0.04) adults suggesting a blunting in the autophagic response during heat stress. In elderly, HSP70 protein and HSPA1A gene expression were both lower when compared to young (1.21 [SD 0.43] vs. 1.80 [SD 0.65]; p=0.02 and 1.58 [SD 1.64] vs. 2.88 [SD 4.29]; p=0.04, respectively) suggesting an age‐associated decline in the heat shock response. These preliminary findings demonstrate that despite greater elevations in core temperature, elderly adults experience blunting in both the autophagy and heat shock response during a prolonged extreme‐heat exposure.Support or Funding InformationCanadian Institutes of Health Research

Prospective study of the effects of sport-related concussion on serum kynurenine pathway metabolites

Reports of neurodegenerative and psychiatric disease in former athletes have increased public concern about the acute and chronic effects of sport-related concussions (SRC). The biological factors underlying individual differences in the psychiatric sequalae of SRC and their role in potential long-term negative outcomes have not been determined. One understudied biological consequence of the known inflammatory response to concussion is the activation of a key immunoregulatory pathway, the kynurenine pathway (KP). Activation of the KP produces several neuroactive metabolites that have been associated with psychiatric and neurodegenerative diseases. We tested the hypothesis that SRC results in an elevation of serum KP metabolites with neurotoxic properties (quinolinic acid [QuinA], 3-hydroxykynurenine [3HK]) together with a reduction in the neuroprotective metabolite kynurenic acid (KynA), and that these metabolites would predict post-concussion psychological symptoms. Additionally, because brain injury is thought to prime the immune system, a secondary goal was to test the hypothesis that athletes with acute SRC and a history of prior SRC would have elevated neurotoxic relative to neuroprotective KP metabolites compared to athletes that were concussed for the first time. High school and collegiate football players (N = 1136) were enrolled at a preseason baseline visit that included clinical testing and blood specimen collection. Athletes that suffered a SRC (N = 59) completed follow-up visits within 6-hours (early-acute), at 24–48 h (late-acute) and at 8, 15, and 45 days post-injury. Uninjured contact sport (CC; N = 54) and non-contact sport athletes completed similar visits and served as controls (NCC; N = 30). SRC athletes had significantly elevated psychological symptoms, assessed using the Brief Symptom Inventory-18 (BSI), acutely following injury relative to both control groups. There was a group-by-visit interaction on the ratio of KynA to 3HK in serum, a neuroprotective index, with elevated KynA/3HK in athletes with SRC at the early-acute visit relative to later visits. Importantly, athletes with greater elevation in this neuroprotective index at the early-acute visit reported fewer depressive symptoms at the late-acute visit. Finally, SRC athletes with prior concussion had significantly lower serum KynA/QuinA at all visits compared to SRC athletes with no prior concussion, an effect driven by elevated QuinA in SRC athletes with prior concussion. These results suggest that early-acute activation of the KynA branch of the KP may protect against the development of depressive symptoms following concussion. Furthermore, they highlight the potential of serum QuinA as a biomarker for repetitive head injury and provide insight into possible mechanisms linking prior concussion with subsequent injury.

The Influence of Knickpoints on the Erosion in Songlin River Basin

Based on fieldwork and the longitudinal section obtained by ArcGIS, seven major knickpoints in Songlin River Basin are located. It is found that the regions with a great average elevation difference between ridge and valley suffer more from disasters such as collapse, landslides, and debris flows. Dimensionless number Vindex is used to quantitatively describe the cross-section of the Songlin River Valley. The Vindex coefficient is below 0 outside the upstream influence of knickpoint and in downstream of knickpoint and it is over 0 in the upstream of knickpoint and at the knickpoint. The overall change trend is “super V shape-U shape-super V shape”. The formation and development of knickpoints strongly influence the geomorphological characteristics of the Songlin River Basin. Due to the rising erosion base level of the upstream of knickpoint, sediment is deposited and the incision rate of riverbed decreases or it even stops down cutting. In this way, the average elevation difference between ridge and valley is tend to reduce, which lowers the energy that causes geological hazards and improves the stability of the upstream. The gradient of both riverbanks decreases, forming a flat and wide U-shaped river valley. Although the elevation difference between the river and the downstream watershed of the knickpoint remains constant, the current energy increases and the erosion is still severe, keeping the valley in a V shape.

Chapter 3 - Adaptations in autonomic nervous system regulation in normal and hypertensive pregnancy

There is an increase in basal sympathetic nerve activity (SNA) during normal pregnancy; this counteracts profound primary vasodilation. However, pregnancy also impairs baroreflex control of heart rate and SNA, contributing to increased mortality secondary to peripartum hemorrhage. Pregnancy-induced hypertensive disorders evoke even greater elevations in SNA, which likely contribute to the hypertension. Information concerning mechanisms is limited. In normal pregnancy, increased angiotensin II acts centrally to support elevated SNA. Hypothalamic sites, including the subfornical organ, paraventricular nucleus, and arcuate nucleus, are likely (but unproven) targets. Moreover, no definitive mechanisms for exaggerated sympathoexcitation in hypertensive pregnancy have been identified. In addition, normal pregnancy increases gamma aminobutyric acid inhibition of the rostral ventrolateral medulla (RVLM), a key brainstem site that transmits excitatory inputs to spinal sympathetic preganglionic neurons. Accumulated evidence supports a major role for locally increased production and actions of the neurosteroid allopregnanolone as one mechanism. A consequence is suppression of baroreflex function, but increased basal SNA indicates that excitatory influences predominate in the RVLM. However, many questions remain regarding other sites and factors that support increased SNA during normal pregnancy and, more importantly, the mechanisms underlying excessive sympathoexcitation in life-threatening hypertensive pregnancy disorders such as preeclampsia.

Topographic controls on ecosystem evapotranspiration and net primary productivity under climate warming in the Taihang Mountains, China

Topography is a key control of mountain ecosystems and the corresponding ecohydrological processes in mountain environments. This study examines the influence of topography on variations in mountain ecohydrology under climate warming in the Taihang Mountains in China. The BioGeochemicalCycles (BIOME–BGC) ecosystem model was modified and used to evaluate ecosystem evapotranspiration (ET) and net primary productivity (NPP) for deciduous broadleaf trees, shrubs and grass at different elevation gradients and examine the changes in these variables under a 3 °C–warming scenario with no precipitation changes. The results showed that the ET and NPP of deciduous broadleaf trees and shrubs increased with elevation below 1500 m and decreased with elevation above 1500 m. The NPP and ET of deciduous broadleaf trees and shrubs decreased in response to warming below 1500 m, and increased above 1500 m. For grass, the ET and NPP slightly decreased with greater elevation and increased under climate warming. Combined with the influence of precipitation on ET and NPP, the response to warming can be explained as follows: deciduous broadleaf trees are under water stress in low–middle elevation and under energy stress in high elevation. Shrubs were influenced by water conditions with an optimal precipitation of 600 mm at low–middle elevation and under energy stress in high elevation. Grass was under energy stress at all elevations. The results of this study are important for identifying topographic and climate change impacts on mountain ecosystem and can provide support for planning and management of future ecosystem restoration in the Taihang Mountains.

Vegetation change and its influence on runoff and sediment in different landform units, Wei River, China

China has been ranked first in its contribution to the newly increased green areas in the world since 2000. Because of the significant differences in natural and geographical conditions in China, the spatial variation of vegetation varies greatly. We selected the Wei River basin in the transition zone between the Qinling Mountains and the Loess Plateau as the research object. Based on MOD13Q1 normalized difference vegetation index (NDVI) data, the characteristics of and factors influencing vegetation restoration, and their effects on the process of runoff-sediment under various landform units (Loess Plateau, Guanzhong Plain and Qinling Mountain areas) were studied using statistical and trend analyses. Our results indicated that the NDVI in 68.02% of the total research area had significantly increased (p < 0.05), with the fastest vegetation restoration in the loess area. The Theil Sen slopes in the loess, mountain and plain areas were 0.0095/year, 0.0049/year and 0.0013/year, respectively, with significant differences among them (p < 0.05). In the loess area, vegetation restoration rate was slightly higher in the zone with an elevation of 1000–2500 m than 500–1000 m. The fastest vegetation restoration in the mountains was in mountainous areas at low altitude, and the rate tended to decrease with greater elevation. In addition, the fastest vegetation restoration in the loess and mountain regions was in areas with gentle slopes of 5–15°. The relationship between vegetation and precipitation was stronger in the mountains than in the loess area. The results also revealed that improvement in vegetation coverage of cultivated and grassland was the leading cause of vegetation restoration in loess and mountain areas, but urbanization was the main factor affecting vegetation degradation in the plain. In the context of vegetation restoration, change in precipitation was still the dominant factor affecting variation in runoff and sediment load. In the loess area, vegetation restoration has a greater impact on sediment load, while in the Qinling Mountains, vegetation restoration mainly affects runoff.

Exercise Thermoregulation with a Simulated Burn Injury: Impact of Air Temperature.

To evaluate whether the detrimental effect of a simulated burn injury on exercise thermoregulation is dependent on air temperature. On eight occasions, nine males cycled for 60 min at a fixed metabolic heat production (6 W·kg) in air temperatures of 40°C or 25°C with simulated burn injuries of 0% (Control), 20%, 40%, or 60% of total body surface area (TBSA). Burn injuries were simulated by covering the skin with an absorbent, vapor-impermeable material to impede evaporation from the covered areas. Core temperature was measured in the gastrointestinal tract via telemetric pill. In 40°C conditions, greater elevations in core temperature were observed with 40% and 60% TBSA simulated burn injuries versus Control (P < 0.01). However, at 25°C, core temperature responses were not different versus Control with 20%, 40%, and 60% TBSA simulated injuries (P = 0.97). The elevation in core temperature at the end of exercise was greater in the 40°C environment with 20%, 40%, and 60% TBSA simulated burn injuries (P ≤ 0.04). Simulated burn injuries ≥20% TBSA exacerbate core temperature responses in hot, but not temperate, air temperatures. These findings suggest that the U.S. Army's standard for inclusion of burned soldiers is appropriate for hot conditions, but could lead to the needless discharge of soldiers who could safely perform their duties in cooler training/operational settings.

Solar radiation and the validity of infrared tympanic temperature during exercise in the heat.

We investigated the validity of infrared tympanic temperature (IR-Tty) during exercise in the heat with variations in solar radiation. Eight healthy males completed stationary cycling trials at 70% peak oxygen uptake until exhaustion in an environmental chamber maintained at 30°C with 50% relative humidity. Three solar radiation conditions, 0, 250 and 500W/m2, were tested using a ceiling-mounted solar simulator (metal-halide lamps) over a 3 × 2m irradiated area. IR-Tty and rectal temperature (Tre) were similar before and during exercise in each trial (P > 0.05). Spearman's rank correlation coefficient (rs) demonstrated very strong (250W/m2, rs = 0.87) and strong (0W/m2, rs = 0.73; 500W/m2, rs = 0.78) correlations between IR-Tty and Tre in all trials (P < 0.001). A Bland-Altman plot showed that mean differences (SD; 95% limits of agreement; root mean square error) between IR-Tty and Tre were - 0.11°C (0.46; - 1.00 to 0.78°C; 0.43 ± 0.16°C) in 0W/m2, - 0.13°C (0.32; - 0.77 to 0.50°C; 0.32 ± 0.10°C) in 250W/m2 and - 0.03°C (0.60; - 1.21 to 1.14°C; 0.46 ± 0.27°C) in 500W/m2. A positive correlation was found in 500W/m2 (rs = 0.51; P < 0.001) but not in 250W/m2 (rs = 0.04; P = 0.762) and 0W/m2 (rs = 0.04; P = 0.732), indicating a greater elevation in IR-Tty than Tre in 500W/m2. Percentage of target attainment within ± 0.3°C between IR-Tty and Tre was higher in 250W/m2 (100 ± 0%) than 0 (93 ± 7%) and 500 (90 ± 10%; P < 0.05) W/m2. IR-Tty is acceptable for core temperature monitoring during exercise in the heat when solar radiation is ≤ 500W/m2, and its accuracy increases when solar radiation is 250W/m2 under our study conditions.

Precise evaluation the effect of microwave irradiation on the properties of palm kernel oil biodiesel used in a diesel engine

Abstract Palm kernel oil (PKO) has an appropriate oil content which can be utilized for biodiesel production. Sparse studies have been performed on its ability as well as the produced biodiesel properties and performance in the diesel engine. Further, no study has been performed on the conversion of PKO via microwave irradiation and comparing the PKO biodiesel abilities combusted in diesel engines with those prepared by conventional methods. For this purpose, PKO was directly extracted from date palm fruits (Phoenix dactylifera) with microwave and conventional heating systems utilized for conversion of PKO to biodiesel. In addition to optimization of microwave-assisted transesterification reaction conditions, variations of temperature during each run were carefully monitored. The results revealed that palm kernel has 10 wt% of oil containing high unsaturated fatty acids and free fatty acid (FFA). The transesterification reaction was sharply accelerated by microwave power such that the reaction time diminished from 90 min for conventional method to 2.5 min. The results of temperature monitoring confirmed great elevation in the reaction temperature (over boiling point of methanol) with the rise of microwave power and methanol/oil ratio. Moreover, reduction of temperature occurred with more loading of catalyst due to greater formation of soap. Both high and low temperatures showed negative effects on the yield of transesterification reaction. The performance and emissions gas evaluation of the engine fueled by PKO biodiesel produced by microwave and conventional heating system indicated that the fuel produced by microwave irradiation can sharply reduce the CO and HC and insignificantly increase NOx in exhaust emission as compared to fuel produced by the conventional method. Also, higher amounts of microwave-assisted produced PKO biodiesel can be blended with net diesel fuel to use in diesel engines. The results suggested that microwave irradiation can considerably influence the phytochemical properties of biodiesel and improve its combustion profile in the diesel engine and exhaust gas emissions.

Obesity in acute alcoholic hepatitis increases morbidity and mortality.

BackgroundAlcohol and obesity synergise to increase the risk of liver-related mortality. We examined the influence of adiposity on clinical outcomes in alcoholic hepatitis (AH) and the underlying inflammatory crosstalk between adipose tissue (AT) and the liver.MethodsA cohort of 233 patients with AH from the UK and USA provided data to analyse the effects of obesity in AH. Body mass index was corrected for the severity of ascites, termed cBMI. Inflammatory and metabolic profiling was undertaken by proteome analysis of human serum samples. The effect of alcohol on adipose tissue and CXCL11 expression was studied in 3 T3-derived adipocytes and in mice using the high-fat diet-plus-binge ethanol model.FindingsObesity was common amongst patients with AH, seen in 19% of individuals. Obesity (HR 2.22, 95%CI 1.1–4.3, p = .022) and underweight (HR 2.38, 1.00–5.6, p = .049) were independently associated with mortality at 3 months. Proteome analysis demonstrated multiple metabolic and inflammatory factors differentially expressed in obese AH verse lean AH, with CXCL11 being the most elevated factor in obese AH. In vitro analysis of cultured adipocytes and in vivo analysis of mouse models showed that alcohol induced CXCL11 expression in AT, but not in liver.InterpretationObesity is common in AH and associated with a greater than two-fold increase in short-term mortality. Obese AH is associated with a different inflammatory phenotype, with the greatest elevation in CXCL11. These data confirm that adiposity is clinically important in acute alcohol-related liver disease and illustrate the adipose-liver inflammatory axis in AH.FundThis work was supported in part by an EASL Sheila Sherlock Physician Scientist Fellowship. The funder played no role in gathering or analysing data or writing the manuscript. This paper presents independent research supported by the NIHR Birmingham Biomedical Research Centre at the University Hospitals Birmingham NHS Foundation Trust and the University of Birmingham. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Urinary apolipoprotein AI in children with kidney disease

Although high-density lipoprotein (HDL) modulates many cell types in the cardiovascular system, little is known about HDL in the kidney. We assessed urinary excretion of apolipoprotein AI (apoAI), the main protein in HDL. We enrolled 228 children with various kidney disorders and 40 controls. Urinary apoAI, albumin, and other markers of kidney damage were measured using ELISA, apoAI isoforms with Western blot, and renal biopsies stained for apoAI. Patients followed in nephrology clinic had elevated urinary apoAI vs. controls (median 0.074μg/mg; interquartile range (IQR) 0.0160-0.560, vs. 0.019μg/mg; IQR 0.004-0.118, p < 0.001). Patients with tubulopathies, renal dysplasia/congenital anomalies of the kidney and urogenital tract, glomerulonephritis, and nephrotic syndrome (NS) in relapse had the greatest elevations (p ≤ 0.01). Patients with NS in remission, nephrolithiasis, polycystic kidney disease, transplant, or hypertension were not different from controls. Although all NS in relapse had higher apoAI excretion than in remission (0.159 vs. 0.0355μg/mg, p = 0.01), this was largely driven by patients with focal segmental glomerulosclerosis (FSGS). Many patients, especially with FSGS, had increased urinary apoAI isoforms. Biopsies from FSGS patients showed increased apoAI staining at proximal tubule brush border, compared to diffuse cytoplasmic distribution in minimal change disease. Children with kidney disease have variably increased urinary apoAI depending on underlying disease. Urine apoAI is particularly elevated in diseases affecting proximal tubules. Kidney disease is also associated with high molecular weight (HMW) apoAI isoforms in urine, especially FSGS. Whether abnormal urinary apoAI is a marker or contributor to renal disease awaits further study.

Matrix morphology and the particle dispersion in HDPE nanocomposites with enhanced wear resistance

Abstract High density polyethylene nanocomposites were prepared by melt mixing of varying type of nanopowders in the presence of vinyltrimethoxysilane (VTMS) coupling agent. Three spherical/irregular-shaped nanopowders, fumed Al2O3, γ-Al2O3, cubic titanium nitride (TiN) (1.5 vol-%), and high aspect ratio graphene oxide platelets (GO) (0.5 vol-%) were investigated in a high molecular weight HDPE matrix. Significant differences in the dispersion quality between the nanopowders were found by TEM and AFM. Degree of crystallinity of the nanocomposites (DSC/XRD) was consistently lower than in the neat HDPE polymer. The particularly well dispersed fumed Al2O3, γ-Al2O3 and GO nanopowders induced significant modification on the micromechanical properties of the HDPE. For the first time, great enhancement in the sliding wear performance, and an improvement in the abrasive wear performance was found in the high molecular weight HDPE nanocomposites. DSC analyses showed elevations in the glass transition temperatures and the peak melting temperatures of the nanocomposites. XRD peak splitting in the HDPE + GO and the HDPE + γ-Al2O3 nanocomposites suggest the emergence of a concurrent orthorhombic HDPE phase. Formation of new phases was also supported by DSC analyses showing broad and multimodal melting peaks. Scherrer analyses of XRD data showed slightly increased HDPE crystalline thicknesses in the range of 15–20 nm in the nanocomposites, which was in line with the TEM and AFM observations. The great elevation in the melting temperatures of the HDPE nanocomposites with fumed Al2O3 and γ-Al2O3 could not be attributed to the polymer lamellar thickness, but rather to the altered properties of the solid amorphous phase stemming for the nanopowder additives.

Real-time social stress response and subsequent alcohol use initiation among female adolescents.

Adolescents who are particularly sensitive to social stress may be vulnerable to earlier alcohol consumption and related problems. Although a small literature supports this contention, previous studies mostly relied on retrospective self-report. The current study used discrete-time survival analysis (DTSA) to test whether real-time social stress responding (via laboratory induction) and social anxiety symptoms predicted 12-month alcohol onset in an alcohol-naïve sample of young female adolescents. Anxiety elicited by the task was expected to predict greater and earlier rates of alcohol incidence, particularly among girls with higher levels of self-reported social anxiety symptoms. Participants were 104 community-recruited girls (ages 12-15 years) who completed a modified Trier Social Stress Test and questionnaires; follow-up calls were conducted at 3, 6, 9, and 12 months after the laboratory visit. Self-reported anxiety was assessed in response to the stressor following acclimation (baseline), instruction (anticipation), and speech (posttask). By 12 months, 30.8% of the sample had consumed a full alcoholic beverage. The DTSA revealed that girls with higher levels of social anxiety and greater elevations in anticipatory (but not posttask) anxiety compared to baseline had earlier alcohol initiation. This is the first study to examine the role of both laboratory-induced anxious responding and retrospective reports of social anxiety as prospective predictors of alcohol incidence. These preliminary findings suggest that adolescent girls who are more sensitive to social stress may be at risk for experimenting with alcohol earlier than their peers. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Impact of whole egg intake on blood pressure, lipids and lipoproteins in middle-aged and older population: A systematic review and meta-analysis of randomized controlled trials

Background and aimEffects of whole egg consumption on cardiovascular diseases (CVD) risk in the middle-aged and older population remain unclear due to inconsistent findings from observational and randomized controlled trials (RCTs). This meta-analysis aimed to assess the impacts of whole egg and egg category (whole eggs versus egg substitutes) intake quantity on CVD risk factors from systematically searched RCTs. Egg substitutes were hypothesized to have minimal effects of the blood lipid and lipoprotein profile as they are void of dietary cholesterol. Methods and resultsAs many as 434 studies identified from PubMed, Cochrane Library, CINAHL and Medline (Ovid) databases were screened and data were extracted from 8 selected RCTs. Quality of the selected studies were assessed and the overall effect sizes of weighted mean differences (WMD) were calculated using a random effects model. Non-differential effects in blood pressures, lipids and lipoproteins were observed when >4 whole eggs/week compared to ≤4 whole eggs/week were consumed. Intake of >4 whole eggs/week compared to equivalent amounts of egg substitutes caused greater elevations in blood total cholesterol (WMD: 0.198 mmol/L; 95% CIs: 0.056, 0.339), HDL cholesterol (WMD: 0.068 mmol/L; 95% CIs: 0.006, 0.130) and LDL cholesterol (WMD: 0.171 mmol/L; 95% CIs: 0.028, 0.315) but did not differentially affect triglycerides concentration. ConclusionOverall, the results support the notion that quantity of whole egg intake does not affect CVD risk factors and consuming egg substitutes may also be beneficial compared to whole eggs on lowering CVD risk in the middle-aged and older population.

Loss of NF-\u03baB p50 function synergistically augments microglial priming in the middle-aged brain

BackgroundWhile NF-κB p50 function is impaired in central nervous system disease, aging in non-CNS tissues, and response to reactive oxygen species, the role of NF-κB p50 in aging-associated microglial pro-inflammatory priming is poorly understood.MethodsMale NF-κB p50+/+ and NF-κB p50−/− mice at three different ages (1.5–3.0 month old, 8.0–11.0 month old, and 16.0–18.0 month old) were treated with LPS (5 mg/kg, IP) to trigger peripheral inflammation, where circulating cytokines, neuroinflammation, microglia morphology, and NF-κB p50/p65 function in brain tissue were determined 3 h later.ResultsPeripheral LPS injection in 9-month-old C57BL/6 mice resulted in lower NF-κB p50 DNA binding of nuclear extracts from the whole brain, when compared to 3-week-old C57BL/6 mice, revealing differences in LPS-induced NF-κB p50 activity in the brain across the mouse lifespan. To examine the consequences of loss NF-κB p50 function with aging, NF-κB p50+/+ and NF-κB p50−/− mice of three different age groups (1.5–3.0 month old, 8.0–11.0 month old, and 16.0–18.0 month old) were injected with LPS (5 mg/kg, IP). NF-κB p50−/− mice showed markedly elevated circulating, midbrain, and microglial TNFα when compared to NF-κB p50+/+ mice at all ages. Notably, the 16.0–18.0-month-old (middle aged) NF-κB p50−/− mice exhibited synergistically augmented LPS-induced serum and midbrain TNFα when compared to the younger (1.5–3.0 month old, young adult) NF-κB p50−/− mice. The 16.0–18.0-month-old LPS-treated NF-κB p50−/− mice also had the highest midbrain IL-1β expression, largest number of microglia with changes in morphology, and greatest elevation of pro-inflammatory factors in isolated adult microglia. Interestingly, aging NF-κB p50−/− mice exhibited decreased brain NF-κB p65 expression and activity.ConclusionsThese findings support that loss of NF-κB p50 function and aging in middle-aged mice may interact to excessively augment peripheral/microglial pro-inflammatory responses and point to a novel neuroinflammation signaling mechanism independent the NF-κB p50/p65 transcription factor in this process.

Obesity Increases Morbidity and Mortality in Alcoholic Hepatitis

Background: Alcohol and obesity synergise to increase the risk of liver-related mortality. We examined the influence of adiposity on clinical outcomes in alcoholic hepatitis (AH) and the underlying inflammatory crosstalk between adipose tissue (AT) and the liver. Methods: A cohort of patients with AH from the UK and USA provided data to analyse the effects of obesity in AH. Body mass index was corrected for the severity of ascites, termed cBMI. Inflammatory and metabolic profiling was undertaken by proteome analysis of human serum samples. The effect of alcohol on adipose tissue and CXCL11 expression was studied in 3T3-derived adipocytes and in mice using the high-fat diet-plus-binge ethanol model. Findings: Obesity was common amongst patients with AH, seen in 19% of individuals. cBMI correlated with volume AT (r2= 0.623, p<0.001), but not with volume of muscle (r2=0.03, p=0.215). Obesity (HR 2.22, 95%CI 1.1-4.3, p=0.022) and underweight (HR 2.38, 1.00-5.6, p=0.049) were independently associated with mortality at 3 months. Proteome analysis demonstrated multiple metabolic and inflammatory factors differentially expressed in obese AH verse lean AH, with CXCL11 being the most elevated factor in obese AH. In vitro analysis of cultured adipocytes and in vivo analysis of mouse models confirmed that alcohol induces CXCL11 expression in AT but not in liver. Interpretation: Obesity is common in AH and associated with a greater than two-fold increase in short-term mortality. Obese AH is associated with a different inflammatory phenotype, with the greatest elevation in CXCL11. These data confirm that adiposity is clinically important in acute alcohol-related liver disease and illustrate the adipose-liver inflammatory axis in AH. Funding: This work was supported in part by an EASL Sheila Sherlock Physician Scientist Fellowship. The funder played no role in gathering or analysing data or writing the manuscript. Declaration of Interest: No authors have any conflicts of interest to declare. Ethical Approval: The collection of samples was approved by research ethics committee (reference 06/Q27108/11).

Primary Sclerosing Cholangitis: A Concise Review of Diagnosis and Management.

Primary sclerosing cholangitis is a rare, chronic cholestatic liver disease characterized by progressive idiopathic stricturing of the biliary system, typically leading to cirrhosis, end-stage liver disease, and colonic or hepatobiliary malignancy. Its presentation is often that of asymptomatic alkaline phosphatase elevation. When symptoms are present, they typically include fatigue, pruritus, or jaundice. The diagnosis can be confirmed via cholangiography, either magnetic resonance cholangiography (MRCP) or endoscopic retrograde cholangiography if the former is inconclusive. The clinical course is marked by progressive liver disease leading to cirrhosis with its attendant complications of portal hypertension, often including recurrent episodes of cholangitis. Greater elevation in alkaline phosphatase or liver stiffness is associated with worse clinical outcomes. Management includes endoscopic treatment of symptomatic biliary strictures and evaluation of dominant strictures as no adequate medical treatment is available. Multiple medical therapies are under evaluation. Ultimately, liver transplantation may be necessary for management of decompensated cirrhosis or disabling symptoms. There is also a markedly increased risk of cancer, notably including cholangiocarcinoma and gallbladder and colorectal cancers (particularly in patients with colitis). Cancer screening can be done with semi-annual liver imaging (MRCP or ultrasound) and colonoscopy every 1-2years in those with colitis.