229 research outputs found
Investigating the cost-effective energy efficiency practices with mitigated rebound: the case of energy intensive industries
The present study aims at finding a practical policy for reducing energy consumption in through simultaneous energy subsidy reduction and energy efficiency improvement. To be a practical solution, the efficiency practices should be chosen from feasible energy efficiency potentials. To mitigate the economy-wide rebound effect, energy price should be increased in accordance with efficiency enhancement.
The combination of a top-down dynamic general equilibrium model with a bottom-up efficiency improvement module is used to find the set of efficiency practices that should be realized in each period along with the required increase in energy prices. Choosing efficiency practices depends on their costs and on the available funds. The model is applied for the energy-intensive industries in Iran.
The model results show that over less than ten years, the energy efficiency of electrical and natural gas equipment in energy intensive industries of Iran can be increased by 12.7% and 18.1% respectively. The rebound effect starts with values above 80% and then falls below zero percent which indicates the success of the proposed policy in preventing the rebound effect. Results also demonstrate that the implementation of the policy realizes the 4% reduction in CO2 emissions by 2030 which is Iran's unconditional pledge
Supplier Knowledge Management For Supplier Development
Due to rapid and unpredictable changes in the business environment, nowadays organizations have to be innovative to survive in the marketplace. Many firms have applied knowledge management to reduce production costs, innovate new products, and attract customers and suppliers. Hence, firm's management has to maintain competitive advantage by providing inputs through a dynamic supplier network. Supplier development programs help businesses to identify collaborative suppliers. Therefore, Supplier Knowledge Management plays an important role for the firms to create switching costs and raise barriers to entry. In this paper, initially we define knowledge management, and supplier knowledge management, and then a conceptual framework is presented to enhance supplier performance. We will demonstrate how companies can benefit by adopting supplier knowledge management
Real-Time FPGA-Based Testbed for Evaluating Digital Predistortion in Fully Digital MIMO Transmitters
As one of the key enabling technologies of 5G networks, massive multiple-input, multiple-output (MIMO) transmitters use many transmit chains to ensure a very high data rate and acceptable signal quality. Realizing Massive MIMO not only includes increasing antenna count but also requires proportionally more power amplifiers (PAs). Digital predistortion (DPD) is a well-established signal processing method that mitigates the non-linearities of a PA when operated near saturation. Design tradeoffs must be carefully considered to reduce the system's overall power requirements given the high PA count in MIMO systems. This implies DPD power consumption for each transmission chain must be minimized. Apart from this, larger transmission bandwidths in next-generation networks require high hardware clock rates on the order of a few gigahertz. Current hardware can satisfy clock rates of up to hundreds of megahertz. Thus, there is a need for parallelized signal processing methods to meet bandwidth requirements.
This thesis investigates and addresses some challenges for deploying massive MIMO systems by designing and building a reconfigurable digital signal processing (DSP) testbed that allows for the implementation and validation of real-time DSP algorithms including DPD, for fully digital massive MIMO transceivers. This testbed allows transmission of up to 16 fully digital transmission chains at sub-6 GHz frequencies and supports up to 120 MHz of modulation bandwidths. Finally, a low-complexity and parallelized piecewise-linear (PWL) dual-input dual-output (DISO) DPD solution is proposed for linearizing MIMO transmitters. This DPD solution is realized with a commercially available field-programmable-gate-array (FPGA)
Determination of serum visfatin level in patients with Behcet disease, comparing with normal population
Background: Behcet’s disease is an inflammatory, systemic and chronic disorder with
unknown etiology affecting multiple systems of body (1). The cause is not clear but seems
to be multifactorial, including immune system dysfunction (humoral and cellular immune
defects), endothelial cell dysfunction and genetic predisposition (2). White adipose tissue
produces variety of proteins in the name of adipocytokines, with important roles in body
metabolism. One of these newly identified secreted adipocytokines is visfatin, which is
secreted by the visceral fat and its plasma level increases during the obesity. It has insulinmimetic
effects in metabolism of cultured cells and activates the insulin receptor (3). Visfatin
stimulates inflammatory cells like monocytes and can induces increasing circulating level
of IL-6 in mice. It have been considered as a new proinflammatory adipocytokine (4). Previous
studies have evaluated visfatin level in immunologic disorders like rheumatoid arthritis
and showed it was significantly higher in comparing to control subjects (4,5,6). There was
no evaluation in patients with behcet disease yet.
Objectives: We have evaluated visfatin level in patients with behcet disease finding inflammatory
role of that in pathogenesis and clinical manifestations of behcet disease.
Methods: We have evaluated 40 patients with Behcet’s disease fulfilled the International
Study Group Criteria for the Diagnosis of Behc¸et’s Disease (ISG) and 40 healthy subjects
from healthy candidates referring to behcet clinic of Shiraz medical university as a referral
center for these patients in south Iran. Both groups have been matched for age, body mass
index (BMI) and sex. Visfatin was checked in both groups using ELISA Kit.
Results: There were no significant difference between cases and controls in mean concentration
of visfatin level (P = 0.61). Difference in the visfatin level between patients with
active and inactive manifestations of Behcet’s disease approximated to the significant levels
(6.13 3.20 and 4.25 2.73, respectively; P = 0.07).
Conclusion: In view of our study, we have concluded that visfatin levels may affect the
clinical manifestations of BD maybe as a proinfalmmatory marker in pathogenesis and
active manifestations of Behcet’s disease although more cases should be included in future
works
2.20 Behcet’s disease and miscellaneous rheumatic conditions
Background: Behcet’s disease is an inflammatory, systemic and chronic disorder with
unknown etiology affecting multiple systems of body (1). The cause is not clear but seems
to be multifactorial, including immune system dysfunction (humoral and cellular immune
defects), endothelial cell dysfunction and genetic predisposition (2). White adipose tissue
produces variety of proteins in the name of adipocytokines, with important roles in body
metabolism. One of these newly identified secreted adipocytokines is visfatin, which is
secreted by the visceral fat and its plasma level increases during the obesity. It has insulinmimetic
effects in metabolism of cultured cells and activates the insulin receptor (3). Visfatin
stimulates inflammatory cells like monocytes and can induces increasing circulating level
of IL-6 in mice. It have been considered as a new proinflammatory adipocytokine (4). Previous
studies have evaluated visfatin level in immunologic disorders like rheumatoid arthritis
and showed it was significantly higher in comparing to control subjects (4,5,6). There was
no evaluation in patients with behcet disease yet.
Objectives: We have evaluated visfatin level in patients with behcet disease finding inflammatory
role of that in pathogenesis and clinical manifestations of behcet disease.
Methods: We have evaluated 40 patients with Behcet’s disease fulfilled the International
Study Group Criteria for the Diagnosis of Behc¸et’s Disease (ISG) and 40 healthy subjects
from healthy candidates referring to behcet clinic of Shiraz medical university as a referral
center for these patients in south Iran. Both groups have been matched for age, body mass
index (BMI) and sex. Visfatin was checked in both groups using ELISA Kit.
Results: There were no significant difference between cases and controls in mean concentration
of visfatin level (P = 0.61). Difference in the visfatin level between patients with
active and inactive manifestations of Behcet’s disease approximated to the significant levels
(6.13 3.20 and 4.25 2.73, respectively; P = 0.07).
Conclusion: In view of our study, we have concluded that visfatin levels may affect the
clinical manifestations of BD maybe as a proinfalmmatory marker in pathogenesis and
active manifestations of Behcet’s disease although more cases should be included in future
works
Comparison of three malnutrition screening tools prior to allogeneic hematopoietic stem-cell transplantation
BackgroundPrevious studies have shown that malnutrition before hematopoietic stem cell transplantation (HSCT) is associated with poor patient prognoses. There is inconsistency among studies on which nutritional status screening tool is appropriate for malnutrition diagnosis before allo-HSCT. The present study aimed to compare nutritional screening tools in patients with leukemia before allo-HSCT.MethodsAn observational, cross-sectional, and single-center study was conducted in Tehran, Iran. One hundred four adults allo-HSCT candidates aged 18-55 years with leukemia were selected sequentially. Malnutrition assessment was done using three tools, the Global Leadership Initiative on Malnutrition (GLIM), nutritional risk screening 2002 (NRS-2002) and European Society for Clinical Nutrition and Metabolism (ESPEN) criteria. The agreement between malnutrition assessment tools was evaluated with Cohen’s kappa.ResultsThe agreement between GLIM and NRS-2002 was perfect (κ = 0.817, p < 0.001), while the agreement between GLIM and ESPEN was fair (κ = 0.362, p < 0.001). The agreement between NRS-2002 and ESPEN was fair (κ = 0.262, p < 0.001). We also found a moderate agreement for all tools (κ = 0.489, p < 0.001).ConclusionNRS-2002 is an accepted tool for screening malnutrition in hospitalized patients. In the current study, the GLIM criterion perfectly agreed with the NRS-2002. Further studies in the HSCT setting are needed to introduce a valid tool
Influence of enamel matrix derivative on healing of root surfaces after bonding treatment and intentional replantation of vertically fractured roots
Background/Aim: The objectives of this study were to histopathologically evaluate cementum regeneration on root surfaces when an enamel matrix derivative (EMD) was used to bond a vertically fractured root and to evaluate the effectiveness of EMD in inhibiting root resorption. Material and methods: A total of 40 roots from 24 maxillary premolars in beagles were used. The root was vertically fractured using a chisel and mallet. Super-Bond was then used to bond the fractured root. In the experimental group, the root surface was treated with ethylenediaminetetraacetic acid and an EMD. The control group received no treatment. The root was then replanted in its original location. Histopathological observation and measurement using image-analyzing software were carried out after 8 weeks. Results: In the experimental group, shallow resorption cavities developed on the root planed surfaces with new acellular cementum appearing over them. In the control group, no new cementum was seen on the planed surfaces, and there was connective tissue joining the roots. In some of the samples, resorption and multinucleated giant cells were seen. The experimental group showed a significantly larger volume of cementum formation (P < 0.001), and the volume of root resorption was significantly smaller (P = 0.004). Conclusion: When bonding and replanting tooth roots after a vertical fracture, the application of EMD was effective in regenerating cementum on root surfaces from which periodontal ligament had been lost in the area around the fracture line and in reducing the incidence of root resorption
Metformin inhibits polyphosphate-induced hyper-permeability and inflammation
Circulating inflammatory factor inorganic polyphosphate (polyP) released from activated platelets could enhance factor XII and bradykinin resulted in increased capillary leakage and vascular permeability. PolyP induce inflammatory responses through mTOR pathway in endothelial cells, which is being reported in several diseases including atherosclerosis, thrombosis, sepsis, and cancer. Systems and molecular biology approaches were used to explore the regulatory role of the AMPK activator, metformin, on polyP-induced hyper-permeability in different organs in three different models of polyP-induced hyper-permeability including local, systemic shortand systemic long-term approaches in murine models. Our results showed that polyP disrupts endothelial barrier integrity in skin, liver, kidney, brain, heart, and lung in all three study models and metformin abrogates the disruptive effect of polyP. We also showed that activation of AMPK signaling pathway, regulation of oxidant/ anti-oxidant balance, as well as decrease in inflammatory cell infiltration constitute a set of molecular mechanisms through which metformin elicits it's protective responses against polyP-induced hyper-permeability. These results support the clinical values of AMPK activators including the FDA-approved metformin in attenuating vascular damage in polyP-associated inflammatory diseases.Peer reviewe
Adverse events in people taking macrolide antibiotics versus placebo for any indication
BACKGROUND: Macrolide antibiotics (macrolides) are among the most commonly prescribed antibiotics worldwide and are used for a wide range of infections. However, macrolides also expose people to the risk of adverse events. The current understanding of adverse events is mostly derived from observational studies, which are subject to bias because it is hard to distinguish events caused by antibiotics from events caused by the diseases being treated. Because adverse events are treatment-specific, rather than disease-specific, it is possible to increase the number of adverse events available for analysis by combining randomised controlled trials (RCTs) of the same treatment across different diseases. OBJECTIVES:To quantify the incidences of reported adverse events in people taking macrolide antibiotics compared to placebo for any indication.
SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which includes the Cochrane Acute Respiratory Infections Group Specialised Register (2018, Issue 4); MEDLINE (Ovid, from 1946 to 8 May 2018); Embase (from 2010 to 8 May 2018); CINAHL (from 1981 to 8 May 2018); LILACS (from 1982 to 8 May 2018); and Web of Science (from 1955 to 8 May 2018). We searched clinical trial registries for current and completed trials (9 May 2018) and checked the reference lists of included studies and of previous Cochrane Reviews on macrolides.
SELECTION CRITERIA: We included RCTs that compared a macrolide antibiotic to placebo for any indication. We included trials using any of the four most commonly used macrolide antibiotics: azithromycin, clarithromycin, erythromycin, or roxithromycin. Macrolides could be administered by any route. Concomitant medications were permitted provided they were equally available to both treatment and comparison groups.
DATA COLLECTION AND ANALYSIS: Two review authors independently extracted and collected data. We assessed the risk of bias of all included studies and the quality of evidence for each outcome of interest. We analysed specific adverse events, deaths, and subsequent carriage of macrolide-resistant bacteria separately. The study participant was the unit of analysis for each adverse event. Any specific adverse events that occurred in 5% or more of any group were reported. We undertook a meta-analysis when three or more included studies reported a specific adverse event.
MAIN RESULTS: We included 183 studies with a total of 252,886 participants (range 40 to 190,238). The indications for macrolide antibiotics varied greatly, with most studies using macrolides for the treatment or prevention of either acute respiratory tract infections, cardiovascular diseases, chronic respiratory diseases, gastrointestinal conditions, or urogynaecological problems. Most trials were conducted in secondary care settings. Azithromycin and erythromycin were more commonly studied than clarithromycin and roxithromycin.Most studies (89%) reported some adverse events or at least stated that no adverse events were observed.Gastrointestinal adverse events were the most commonly reported type of adverse event. Compared to placebo, macrolides caused more diarrhoea (odds ratio (OR) 1.70, 95% confidence interval (CI) 1.34 to 2.16; low-quality evidence); more abdominal pain (OR 1.66, 95% CI 1.22 to 2.26; low-quality evidence); and more nausea (OR 1.61, 95% CI 1.37 to 1.90; moderate-quality evidence). Vomiting (OR 1.27, 95% CI 1.04 to 1.56; moderate-quality evidence) and gastrointestinal disorders not otherwise specified (NOS) (OR 2.16, 95% CI 1.56 to 3.00; moderate-quality evidence) were also reported more often in participants taking macrolides compared to placebo.The number of additional people (absolute difference in risk) who experienced adverse events from macrolides was: gastrointestinal disorders NOS 85/1000; diarrhoea 72/1000; abdominal pain 62/1000; nausea 47/1000; and vomiting 23/1000.The number needed to treat for an additional harmful outcome (NNTH) ranged from 12 (95% CI 8 to 23) for gastrointestinal disorders NOS to 17 (9 to 47) for abdominal pain; 19 (12 to 33) for diarrhoea; 19 (13 to 30) for nausea; and 45 (22 to 295) for vomiting.There was no clear consistent difference in gastrointestinal adverse events between different types of macrolides or route of administration.Taste disturbances were reported more often by participants taking macrolide antibiotics, although there were wide confidence intervals and moderate heterogeneity (OR 4.95, 95% CI 1.64 to 14.93; Iand#178; = 46%; low-quality evidence).Compared with participants taking placebo, those taking macrolides experienced hearing loss more often, however only four studies reported this outcome (OR 1.30, 95% CI 1.00 to 1.70; Iand#178; = 0%; low-quality evidence).We did not find any evidence that macrolides caused more cardiac disorders (OR 0.87, 95% CI 0.54 to 1.40; very low-quality evidence); hepatobiliary disorders (OR 1.04, 95% CI 0.27 to 4.09; very low-quality evidence); or changes in liver enzymes (OR 1.56, 95% CI 0.73 to 3.37; very low-quality evidence) compared to placebo.We did not find any evidence that appetite loss, dizziness, headache, respiratory symptoms, blood infections, skin and soft tissue infections, itching, or rashes were reported more often by participants treated with macrolides compared to placebo.Macrolides caused less cough (OR 0.57, 95% CI 0.40 to 0.80; moderate-quality evidence) and fewer respiratory tract infections (OR 0.70, 95% CI 0.62 to 0.80; moderate-quality evidence) compared to placebo, probably because these are not adverse events, but rather characteristics of the indications for the antibiotics. Less fever (OR 0.73, 95% 0.54 to 1.00; moderate-quality evidence) was also reported by participants taking macrolides compared to placebo, although these findings were non-significant.There was no increase in mortality in participants taking macrolides compared with placebo (OR 0.96, 95% 0.87 to 1.06; Iand#178; = 11%; low-quality evidence).Only 24 studies (13%) provided useful data on macrolide-resistant bacteria. Macrolide-resistant bacteria were more commonly identified among participants immediately after exposure to the antibiotic. However, differences in resistance thereafter were inconsistent.Pharmaceutical companies supplied the trial medication or funding, or both, for 91 trials.
AUTHORS' CONCLUSIONS: The macrolides as a group clearly increased rates of gastrointestinal adverse events. Most trials made at least some statement about adverse events, such as "none were observed". However, few trials clearly listed adverse events as outcomes, reported on the methods used for eliciting adverse events, or even detailed the numbers of people who experienced adverse events in both the intervention and placebo group. This was especially true for the adverse event of bacterial resistance.</p
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