39 research outputs found
The Ecological Footprint Nowadays
This assessment refers to the ecological footprint which is a way to measure the impacts of human activities on Earth. It basically calculates the demand and consumption that measures the needs of a society, as well as the waste and greenhouse gases that generates daily in productive sea and fertile land areas. Moreover, it measures all the natural resources needed to support the material needs of a population or person through the technology, lifestyle and habits of each country. Subsequently we are going to examine the advantages and disadvantages of the phenomenon that human activities provoke and the ways to eliminate the caused problem. The world-average ecological footprint in 2013 was 2.8 global hectares per person and the average per country ranges from over 10 to under 1 global hectares per person. There is also a high variation within countries, based on individual lifestyle and economic possibilities that we also examine. Summarizing all those effects we are going to analyze open international data as far as the metabolism of the ecological footprint concerns in our word but especially in our country to form prospects for our planet the principles of life cycle assessments with the aid of statistics and charts
Glypican-1, phosphacan/receptor protein-tyrosine phosphatase-ζ/β and its ligand, tenascin-C, are expressed by neural stem cells and neural cells derived from embryonic stem cells
The heparan sulfate proteoglycan glypican-1, the chondroitin sulfate proteoglycan
phosphacan/RPTP (receptor protein-tyrosine
phosphatase)-ζ/β and the extracellular matrix protein
tenascin-C were all found to be expressed by neural stem cells and by neural
cells derived from them. Expression of proteoglycans and tenascin-C increased
after retinoic acid induction of SSEA1-positive ES (embryonic stem) cells to
nestin-positive neural stem cells, and after neural differentiation,
proteoglycans and tenascin-C are expressed by both neurons and astrocytes, where
they surround cell bodies and processes and in certain cases show distinctive
expression patterns. With the exception of tenascin-C (whose expression may
decrease somewhat), expression levels do not change noticeably during the
following 2 weeks in culture. The significant expression, by neural stem cells
and neurons and astrocytes derived from them, of two major heparan sulfate and
chondroitin sulfate proteoglycans of nervous tissue and of tenascin-C, a
high-affinity ligand of phosphacan/RPTP-ζ/β, indicates
that an understanding of their specific functional roles in stem cell
neurobiology will be important for the therapeutic application of this new
technology in facilitating nervous tissue repair and regeneration
Advances in tenascin-C biology
Tenascin-C is an extracellular matrix glycoprotein that is specifically and transiently expressed upon tissue injury. Upon tissue damage, tenascin-C plays a multitude of different roles that mediate both inflammatory and fibrotic processes to enable effective tissue repair. In the last decade, emerging evidence has demonstrated a vital role for tenascin-C in cardiac and arterial injury, tumor angiogenesis and metastasis, as well as in modulating stem cell behavior. Here we highlight the molecular mechanisms by which tenascin-C mediates these effects and discuss the implications of mis-regulated tenascin-C expression in driving disease pathology
Changes in renal function following administration of oral sodium phosphate or polyethylene glycol for colon cleansing before colonoscopy
Changes in renal function were compared in patients receiving oral sodium phosphate (NaP) for colon cleansing and those receiving large-volume polyethylene glycol (PEG) solution to determine whether oral NaP resulted in frequent renal damage that had gone clinically undetected. From 1995 to 2004, a cohort of consecutive patients who had serum creatinine (Cr) drawn immediately before colonoscopy and again after subsequent procedures three months to nine years later (almost 80% of patients between the first and fifth year) were identified. Chronic renal failure (CRF) was defined as an abnormal Cr at repeat measurement or an abnormal Cr clearance as estimated by the Cockroft-Gault equation at the time of repeat Cr measurement. Medications and medical comorbid conditions were recorded. Seven hundred sixty-seven patients (51% female and 49% male; 81% oral NaP and 19% PEG) with normal baseline Cr levels were identified through the endoscopy unit database at the Hotel Dieu Hospital, Queen’s University (Kingston, Ontario). Of these, 55 (7%) developed CRF. Forty-two (6.8%) patients receiving oral NaP developed renal failure compared with 13 patients (8.7%) receiving PEG (Fisher’s exact test; P=0.382), but the magnitude of CRF was small in each group (Cr level lower than 160 μmol/L). Using logistic regression analysis with the choice of preparation, medications and medical comorbid conditions as independent variables, only age and blood pressure were predictive of the development of renal failure (P=0.014 and P=0.001, respectively). Baseline Cr clearance was similiar in both the NaP and PEG groups and the absolute difference after colonoscopy did not differ. The present study concluded that the ingestion of oral NaP for colon cleansing before colonoscopy did not result in frequent renal damage that went clinically undetected
Nonsurgical Management of Severe Esophageal and Gastric Injury Following Alkali Ingestion
The ingestion of caustic substances may result in significant gastrointestinal injury. Endoscopy can play a major role in the initial evaluation and subsequent therapy of such injuries. The case of a 50-year-old man who ingested an alkaline floor stripper is described, including the endoscopic management of esophageal and pyloric strictures, with good functional results. The role of endoscopy, steroids and acid suppression in the management of such patients is also explored