33 research outputs found
A Net Energy Analysis of the Global Agriculture, Aquaculture, Fishing and Forestry System
The global agriculture, aquaculture, fishing and forestry (AAFF) energy system is subject to three unsustainable trends: (1) the approaching biophysical limits of AAFF; (2) the role of AAFF as a driver of environmental degradation; and (3) the long-term declining energy efficiency of AAFF due to growing dependence on fossil fuels. In response, we conduct a net energy analysis for the period 1971–2017 and review existing studies to investigate the global AAFF energy system and its vulnerability to the three unsustainable trends from an energetic perspective. We estimate the global AAFF system represents 27.9% of societies energy supply in 2017, with food energy representing 20.8% of societies total energy supply. We find that the net energy-return-on-investment (net EROI) of global AAFF increased from 2.87:1 in 1971 to 4.05:1 in 2017. We suggest that rising net EROI values are being fuelled in part by ‘depleting natures accumulated energy stocks’. We also find that the net energy balance of AAFF increased by 130% in this period, with at the same time a decrease in both the proportion of rural residents and also the proportion of the total population working in AAFF—which decreased from 19.8 to 10.3%. However, this comes at the cost of growing fossil fuel dependency which increased from 43.6 to 62.2%. Given the increasing probability of near-term fossil fuel scarcity, the growing impacts of climate change and environmental degradation, and the approaching biophysical limits of global AAFF, ‘Odum’s hoax’ is likely soon to be revealed
Targeting RNS/caveolin-1/MMP signaling cascades to protect against cerebral ischemia-reperfusion injuries: potential application for drug discovery
Reactive nitrogen species (RNS) play important roles in mediating cerebral ischemia-reperfusion injury. RNS activate multiple signaling pathways and participate in different cellular events in cerebral ischemia-reperfusion injury. Recent studies have indicated that caveolin-1 and matrix metalloproteinase (MMP) are important signaling molecules in the pathological process of ischemic brain injury. During cerebral ischemia-reperfusion, the production of nitric oxide (NO) and peroxynitrite (ONOO-), two representative RNS, down-regulates the expression of caveolin-1 (Cav-1) and, in turn, further activates nitric oxide synthase (NOS) to promote RNS generation. The increased RNS further induce MMP activation and mediate disruption of the blood-brain barrier (BBB), aggravating the brain damage in cerebral ischemia-reperfusion injury. Therefore, the feedback interaction among RNS/Cav-1/MMPs provides an amplified mechanism for aggravating ischemic brain damage during cerebral ischemia-reperfusion injury. Targeting the RNS/Cav-1/MMP pathway could be a promising therapeutic strategy for protecting against cerebral ischemia-reperfusion injury. In this mini-review article, we highlight the important role of the RNS/Cav-1/MMP signaling cascades in ischemic stroke injury and review the current progress of studies seeking therapeutic compounds targeting the RNS/Cav-1/MMP signaling cascades to attenuate cerebral ischemia-reperfusion injury. Several representative natural compounds, including calycosin-7-O-β-D-glucoside, baicalin, Momordica charantia polysaccharide (MCP), chlorogenic acid, lutein and lycopene, have shown potential for targeting the RNS/Cav-1/MMP signaling pathway to protect the brain in ischemic stroke. Therefore, the RNS/Cav-1/MMP pathway is an important therapeutic target in ischemic stroke treatment.published_or_final_versio
Usefulness of transhepatic portal catheterization in the treatment of insulinomas.
Twenty-four per cent of beta-cell tumours require more than one operation to control the hypoglycaemic syndrome. Almost all of them are small insulinomas undetectable by palpation of the pancreas. Arteriography is too insensitive to detect non-palpable tumours. Transhepatic catheterization of the splenic and portal veins (TPC) can detect the position at which there is an abrupt increase in insulin level indicating the site of the tumour. Routine use of TPC allowed us to locate all 9 insulinomas in which this technique was employed, whereas of 15 patients not studied by TPC only 12 tumours were located at first operation, 2 of which were found by blind resection of the tail of the pancreas. We believe that routine application of TPC to all cases of suspected insulinoma would reduce the incidence of surgical failures, unsuccessful blind resections and lengthy trials of medical therapy before laparotomy
Soy allergy is not common in atopic children: a multicenter study
The aim of the present study was to evaluate the prevalence of soy allergy (positive skin test and positive challenge test) in a large cohort of atopic children, many of them soy fed early in life for several months. In order to investigate the prevalence of soy allergy, two groups of children were enrolled into the study. The first group comprised a cohort of 505 children with personal history suggestive of food allergy. The second group included 243 children born of atopic parents, who had been soy protein formula fed for the first six months of life for the prevention of cow's milk allergy and who had been prospectively followed up, from birth to 5 years. As regards the prevalence of soy allergy in the cohort of children suffering from allergic disease: 31/505 children (6%) had positive skin prick test to soy, however only six of the 31 children with positive skin prick test to soy had positive challenge test to soy. With regard to the prevalence of soy allergy in the children who had been soy protein formula fed in the first six months of life (second group): 14/243 children (6%) had positive skin prick test to soy, but the double blind placebo control oral food challenge to soy was positive in only one of these 14 children. In conclusion documented soy allergy is not common in atopic children
Discovery and Optimization of a Series of 2-Aryl-4-Amino-5-(3',4',5'-trimethoxybenzoyl)Thiazoles as Novel Anticancer Agents.
A new series of tubulin polymerization inhibitors based on the 2-aryl/heteroaryl-4-amino-5-(3',4',5'-trimethoxybenzoyl)thiazole scaffold was synthesized and evaluated for growth inhibition activity on a panel of cancer cell lines, cell cycle effects, and in vivo potency. Structure-activity relationships were elucidated with various substitutions at the 2-position of the thiazole skeleton. Hydrophobic moieties, such as phenyl and 3-thienyl, were well tolerated at this position, and variation of the phenyl substituents had remarkable effects on potency. The most active compound (3b) induced apoptosis through the mitochondrial pathway with activation of caspase-3. We also showed that it has potential antivascular activity since it reduced in vitro endothelial cell migration and disrupted capillary-like tube formation at noncytotoxic concentrations. Furthermore, compound 3b significantly reduced the growth of the HT-29 xenograft in a nude mouse model, suggesting that 3b is a promising new antimitotic agent with clinical potential