803 research outputs found
Cyanogenic Glycosides in Cassava
Cassava is a well-known cyanogenic plant, which contains the cyanogenic glycosides linamarin and lotaustralin, the former being the principal cyanogenic glycoside. The ability to detect and quantify cyanogenic glycosides, capable of generating cyanide, could contribute to prevention of acute and subacute cyanide poisoning from the consumption of improperly processed plants. Enzyme-linked immunosorbent assay (ELISA) can be used to detect and measure the amount of linamarin directly within the fresh cassava or cassava-related products with minimal sample preparation using antibodies as the key detector. However, there has been no antibody and ELISA developed for linamarin detection in foods, hence the need. The aim of the project was to generate polyclonal antibodies (pAbs) obtained by immunizing two New Zealand white rabbits with linamarin (hapten) conjugated to a carrier protein, bovine serum albumin (BSA) using cyanuric chloride as chemical linker to be used with the ELISA. Monoclonal antibodies (mAbs) development was attempted by immunizing four BALB/c mice with linamarin-CC-KLH and 3 BALB/c mice with linamarin-CC-BSA but failed to produce the desired antibodies. PAbs generated by both immunised rabbits were highly immunoreactive with antiserum titre of 1:100,000. The pAbs were able to establish positive inhibition assay towards free linamarin with high specificity and sensitivity (limit of detection of 0.0015 µg/ml and IC50 of 2.1 µg/ml). The optimised ELISA was able to determine the amount of linamarin in fresh cassava and processed products available in the UK market, ranging from 0.003 mg/kg to 43.08 mg/kg fresh and dry weight depending on the products. Levels of linamarin of some fresh cassava products are way beyond the safe limit of 10 mg/kg cyanide allowed in food, a potential health risk to consumers. In contrast, highly processed cassava products contained less than 1.0 mg/kg of linamarin, indicating the effectiveness of proper food processing and preparation in reducing the linamarin content in foods
Sorption kinetics of Zn (II) ion by thermally treated rice husk
Agricultural wastes such as orange peels, tea leave waste, rice husk and corn cobs have been widely studied as sorbents for heavy metal ion removal from various wastewaters. In order to understand their sorption mechanism, the adsorption kinetics is studied. This report describes the kinetics study of a thermally treated rice husk to adsorb Zn (II) ion from an aqueous solution. The adsorbent was obtained by heating the rice husk in a furnace at 500°C for two hours. Increase the contact period improved percentage of the removal of Zn (II) ion until an equilibrium was reached. The data obtained showed that the adsorption of Zn (II) ion by thermally treated rice husk obeyed pseudo-second order kinetics model, which is in agreement with chemisorption as the rate limiting mechanism
Repositioning of the global epicentre of non-optimal cholesterol
High blood cholesterol is typically considered a feature of wealthy western countries(1,2). However, dietary and behavioural determinants of blood cholesterol are changing rapidly throughout the world(3) and countries are using lipid-lowering medications at varying rates. These changes can have distinct effects on the levels of high-density lipoprotein (HDL) cholesterol and non-HDL cholesterol, which have different effects on human health(4,5). However, the trends of HDL and non-HDL cholesterol levels over time have not been previously reported in a global analysis. Here we pooled 1,127 population-based studies that measured blood lipids in 102.6 million individuals aged 18 years and older to estimate trends from 1980 to 2018 in mean total, non-HDL and HDL cholesterol levels for 200 countries. Globally, there was little change in total or non-HDL cholesterol from 1980 to 2018. This was a net effect of increases in low- and middle-income countries, especially in east and southeast Asia, and decreases in high-income western countries, especially those in northwestern Europe, and in central and eastern Europe. As a result, countries with the highest level of non-HDL cholesterol-which is a marker of cardiovascular riskchanged from those in western Europe such as Belgium, Finland, Greenland, Iceland, Norway, Sweden, Switzerland and Malta in 1980 to those in Asia and the Pacific, such as Tokelau, Malaysia, The Philippines and Thailand. In 2017, high non-HDL cholesterol was responsible for an estimated 3.9 million (95% credible interval 3.7 million-4.2 million) worldwide deaths, half of which occurred in east, southeast and south Asia. The global repositioning of lipid-related risk, with non-optimal cholesterol shifting from a distinct feature of high-income countries in northwestern Europe, north America and Australasia to one that affects countries in east and southeast Asia and Oceania should motivate the use of population-based policies and personal interventions to improve nutrition and enhance access to treatment throughout the world.Peer reviewe
A dual‐band voltage‐controlled oscillator in 0.13 <i><b>μ</b></i>m CMOS technology
PurposeThe purpose of this paper is to design and implement a fully integrated low‐phase noise and large tuning range dual‐band LC voltage‐controlled oscillator (VCO) in 0.13 μm complementary metal oxide semiconductor (CMOS) technology.Design/methodology/approachTwo parallel‐connected single‐band VCOs are designed to implement the proposed VCO. Adopting a simple and straight‐forward architecture, the dual‐band VCO is configured to operate at two frequency bands, which are from 1.48 GHz to 1.78 GHz and from 2.08 GHz to 2.45 GHz. A band selection circuit is designed to perform band selection process based on the controlling input signal.FindingsThe proposed VCO features phase noise of −104.7 dBc/Hz and −108.8 dBc/Hz at 1 MHz offset frequency for both low corner and high corner end of the low‐band operation. For high‐band operation, phase‐noise performance of −101.1 dBc/Hz and −110.4 dBc/Hz at 1 MHz offset frequency are achieved. The measured output power of the dual‐band VCO ranges from −8.4 dBm to −5.8 dBm and from −9.6 dBm to −8.0 dBm for low‐band and high‐band operation, respectively. It was also observed that the power differences between the fundamental spectrum and the nearby spurious tone range from −67.5 dBc to −47.7 dBc.Originality/valueThe paper is useful to both the academic and industrial fields since it promotes the concept of multi‐band or multi‐standard system which is currently in demand in the telecommunication industry.</jats:sec
Wpływ wstępnej obróbki na strukturę celulozy bakteryjnej z Nata de Coco (Acetobacter xylinum)
This paper presents a structural analysis of various methods to produce bacterial cellulose (BC) from Nata de Coco (Acetobacter xylinum). BC sheet, BC chem and BC mech powders were successfully prepared using oven drying, chemical and mechanical treatment. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM) were used to analyze the structure of prepared BC. The structure of bacterial cellulose was compared with the structure of commercial microcrystalline cellulose (MCC) and cotton fabric. The XRD results showed that the BC sheet sample had the highest degree of crystallinity (81.76%) compared to cotton cellulose (75.73%). The crystallite size of cotton was larger than the BC sheet, with the value of 6.83 ηm and 4.55 ηm, respectively. The peaks in the FTIR spectra of all BC were comparable to the commercial MCC and cotton fabrics. FESEM images showed that the prepared BC sheet, BC mech, and BC chem had an almost similar structure like commercial MCC and cotton fabric. It was concluded that simple preparation of BC could be implemented and used for further BC preparation as reinforcement in polymer composites, especially in food packaging.Niniejszy artykuł zawiera analizę struktury celulozy bakteryjnej (BC) wytworzonej z Nata de Coco (Acetobacter xylinum) różnymi metodami. Folia BC i proszki BC chem oraz BC mech zo -stały wytworzone poprzez suszenie w piecu, obróbkę chemiczną i mechaniczną. Do oceny struktury celulozy bakteryjnej stosowano dyfrakcję rentgenowską (XRD), spektroskopię Fouriera w podczerwieni (FTIR) i skaningową mikroskopię elektronową z emisją polową (FESEM). Strukturę celulozy bakteryjnej porównano ze strukturą handlowej celulozy mikrokrystalicznej (MCC) i tkaniny bawełnianej. Wyniki XRD wykazały, że najwyższy stopień krystaliczności miała próbka arkusza BC (81,76%) w porównaniu z celulozą bawełnianą (75,73%). Wielkość krystalitów bawełny była większa niż folii BC i wynosiła, odpowiednio, 6,83 ηm oraz 4,55 ηm. Piki widm FTIR wszystkich otrzymanych form celulozy bakteryjnej były porównywalne z komercyjnymi tkaninami bawełnianymi i z celulozy mikrokrystalicznej. Zdjęcia FESEM folii BC oraz proszków BC mech i BC chem również były podobne do komercyjnej MCC i tkaniny bawełnianej. Stwierdzono, że z wykorzystaniem prostych technik można otrzymać BC, która może być stosowana jako wzmocnienie w kompozytach polimerowych, w szczególności w opakowaniach do żywności
Pre-treatment effect on the structure of bacterial cellulose from Nata de Coco (Acetobacter xylinum)
This paper presents a structural analysis of various methods to produce bacterial cellulose (BC) from Nata de Coco (Acetobacter xyllinum). BC sheet, BC chem and BC mech powder were successfully prepared using oven drying, chemical and mechanical treatment. The X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM) were used to analyze the structure of prepared BC. The structure of bacterial cellulose was compared with the structure of commercial microcrystalline cellulose (MCC) and cotton fabric. The XRD results showed that the BC sheet sample had the highest degree of crystallinity (81.76%) compared to cotton cellulose (75.73%). The crystallite size of cotton was larger than the BC sheet, with the value of 6.83 ηm and 4.55 ηm, respectively. The peaks in the FTIR spectra of all BC were comparable to the commercial MCC and cotton fabrics. FESEM images showed that the prepared BC sheet, BC mech, and BC chem had an almost similar structure like commercial MCC and cotton fabric. It was concluded that simple preparation of BC could be implemented and used for further BC preparation as reinforcement in polymer composites, especially in food packaging.</jats:p
International Nosocomial Infection Control Consortium report, data summary of 50 countries for 2010-2015: Device-associated module
•We report INICC device-associated module data of 50 countries from 2010-2015.•We collected prospective data from 861,284 patients in 703 ICUs for 3,506,562 days.•DA-HAI rates and bacterial resistance were higher in the INICC ICUs than in CDC-NHSN's.•Device utilization ratio in the INICC ICUs was similar to CDC-NHSN's.
Background: We report the results of International Nosocomial Infection Control Consortium (INICC) surveillance study from January 2010-December 2015 in 703 intensive care units (ICUs) in Latin America, Europe, Eastern Mediterranean, Southeast Asia, and Western Pacific.
Methods: During the 6-year study period, using Centers for Disease Control and Prevention National Healthcare Safety Network (CDC-NHSN) definitions for device-associated health care-associated infection (DA-HAI), we collected prospective data from 861,284 patients hospitalized in INICC hospital ICUs for an aggregate of 3,506,562 days.
Results: Although device use in INICC ICUs was similar to that reported from CDC-NHSN ICUs, DA-HAI rates were higher in the INICC ICUs: in the INICC medical-surgical ICUs, the pooled rate of central line-associated bloodstream infection, 4.1 per 1,000 central line-days, was nearly 5-fold higher than the 0.8 per 1,000 central line-days reported from comparable US ICUs, the overall rate of ventilator-associated pneumonia was also higher, 13.1 versus 0.9 per 1,000 ventilator-days, as was the rate of catheter-associated urinary tract infection, 5.07 versus 1.7 per 1,000 catheter-days. From blood cultures samples, frequencies of resistance of Pseudomonas isolates to amikacin (29.87% vs 10%) and to imipenem (44.3% vs 26.1%), and of Klebsiella pneumoniae isolates to ceftazidime (73.2% vs 28.8%) and to imipenem (43.27% vs 12.8%) were also higher in the INICC ICUs compared with CDC-NHSN ICUs.
Conclusions: Although DA-HAIs in INICC ICU patients continue to be higher than the rates reported in CDC-NSHN ICUs representing the developed world, we have observed a significant trend toward the reduction of DA-HAI rates in INICC ICUs as shown in each international report. It is INICC's main goal to continue facilitating education, training, and basic and cost-effective tools and resources, such as standardized forms and an online platform, to tackle this problem effectively and systematically
- …