Our trial was conducted to study the effects of formic acid(FA) and potassium di-formate(KDF) in broiler ration on performance, carcass traits, blood biochemical, intestinal microbial load, histological picture of int...Our trial was conducted to study the effects of formic acid(FA) and potassium di-formate(KDF) in broiler ration on performance, carcass traits, blood biochemical, intestinal microbial load, histological picture of intestine and immune parameters of broilers. In this study 360 one-day-old broiler chicks were divided to 3 groups with 3 replicates of 40 chicks each. The trial continued for 35 days. The control group was fed only basal diet(G1). Group 2(G2) were fed basal diet supplemented with FA(5 g/kg diet), and group 3(G3) received basal diet supplemented with KDF(5 g/kg diet). The results showed that both FA and KDF significantly increased body weight gain(BWG), dressing percentage of broilers and significantly decreased feed conversion ratio(FCR)(P < 0.05). The highest percent of breast and thigh was observed in G3. The improvement in villus height was observed in G2 and G3 compared with the control one, and the highest was in G3. The results evidence that the using of FA or KDF in broiler feeds have significant effects on performance, immune parameters, and gut health without having any significant effects on blood biochemical. However, KDF is more effective than FA as little amount of FA reaches the small intestine due to metabolism and absorption, whereas KDF permits a proportion of FA to pass through the fore-gut intact and enter the small intestinal tract. In addition, FA has a strong odor and corrosiveness to gastrointestinal tract which limits its use.展开更多
CDX2 is a nuclear homeobox transcription factor that belongs to the caudalrelated family of CDX homeobox genes. The gene encoding CDX2 is a nonclustered hexapeptide located on chromosome 13q12-13. Homeobox genes play ...CDX2 is a nuclear homeobox transcription factor that belongs to the caudalrelated family of CDX homeobox genes. The gene encoding CDX2 is a nonclustered hexapeptide located on chromosome 13q12-13. Homeobox genes play an essential role in the control of normal embryonic development. CDX2 is crucial for axial patterning of the alimentary tract during embryonic development and is involved in the processes of intestinal cell proliferation, differentiation, adhesion, and apoptosis. It is considered specif ic for enterocytes and has been used for the diagnosis of primary and metastatic colorectal adenocarcinoma. CDX2 expression has been reported to be organ specif ic and is normally expressed throughout embryonic and postnatal life within the nuclei of epithelial cells of the alimentary tract from the proximal duodenum to the distal rectum. In this review, the authors elaborate on the diagnostic utility of CDX2 in gastrointestinal tumors and other neoplasms with intestinal differentiation. Limitations with its use as the sole predictor of a gastrointestinal origin of metastatic carcinomas are also discussed.展开更多
Tumor necrosis factor-alpha (TNF-α) is an important cytokine in generating an immune response against infection with hepatitis C virus (HCV). The functions of TNF-α may be altered by single-nucleotide polymorphisms ...Tumor necrosis factor-alpha (TNF-α) is an important cytokine in generating an immune response against infection with hepatitis C virus (HCV). The functions of TNF-α may be altered by single-nucleotide polymorphisms (SNPs) in its gene structure. We hypothesized that SNPs in TNF-α may be important in determining the outcome of an HCV infection. To test this hypothesis, we investigated the role of the polymorphism -308G/A, which is located in the promoter region of the TNF-α gene, in the progression of HCV infection in Egyptian patients using a quantitative real-time polymerase chain reaction (qRT-PCR). The distribution of this polymorphism and its impact on the serum level of TNF-α was compared between 90 HCV-infected patients [45 with HCV-induced cirrhosis and 45 with HCV-related hepatocellular carcinoma (HCC)] and 45 healthy Egyptian volunteers without any history of liver disease. Our results showed that at the TNF-α -308 position, the G/G allele was most common (78.5% ) in the study population, with the G/A and A/A alleles occurring less frequently (13.3% and 8.1% , respectively). Frequencies of G/G, G/A, and A/A genotypes were 87%, 7%, and 6% in patients with liver cirrhosis and were 94% , 4% , and 2% in patients with HCC, respectively. Serum levels of TNF-α were significantly higher in HCV-infected patients than in healthy controls, indicating that the TNF-α -308 polymorphism does not influence the production of TNF-α. The serum level of TNF-α was positively correlated with HCV infection. Taken together, these findings suggest that the TNF-α -308 polymorphism may not be a host genetic factor associated with the severity of HCV infection, but may be an independent risk factor for HCC.展开更多
Sodium-glucose cotransporter-2 inhibitors (SGLT-2 inhibitors) have transformed diabetes management by targeting renal glucose reabsorption. Designed initially as antidiabetic agents, their ability to lower blood gluco...Sodium-glucose cotransporter-2 inhibitors (SGLT-2 inhibitors) have transformed diabetes management by targeting renal glucose reabsorption. Designed initially as antidiabetic agents, their ability to lower blood glucose levels independently of insulin is well-documented. Beyond glycemic control, emerging research has unveiled their profound cardiorenal benefits. By inhibiting SGLT-2 protein, these drugs enhance glucose excretion in urine, reducing blood glucose levels. This mechanism has translated into significant cardiovascular and renal protection, establishing SGLT-2 inhibitors as pivotal in managing not only diabetes but also cardiovascular and renal diseases. Recent studies have illuminated the broader therapeutic potential of SGLT-2 inhibitors beyond diabetes. Evidence indicates their efficacy in managing heart failure, chronic kidney disease (CKD), and cardiovascular complications in individuals with or without diabetes. This expanded therapeutic landscape has catalyzed a paradigm shift in SGLT-2 inhibitor use, positioning them as key agents in the cardiorenal metabolic continuum. Moreover, their role in the secondary prevention of cardiovascular events and slowing CKD progression in T2DM patients has garnered considerable attention. This consensus-based review aims to offer practical guidance in an algorithmic approach to primary care healthcare professionals to optimize SGLT-2 inhibitors utilization and maximize their benefits. The review seeks to empower clinicians to effectively manage patients who may benefit from SGLT-2 inhibitor therapy by addressing common initiation barriers and optimizing treatment strategies. Additionally, it aims to raise awareness among primary care physicians regarding the multifaceted benefits of these medications and overcome clinical inertia in their adoption into routine clinical practice.展开更多
AIM: To know the epidemiology and outcome of Crohn's disease at King Khalid University Hospital, Riyadh, Saudi Arabia and to compare the results from other world institutions.METHODS: A retrospective analysis of p...AIM: To know the epidemiology and outcome of Crohn's disease at King Khalid University Hospital, Riyadh, Saudi Arabia and to compare the results from other world institutions.METHODS: A retrospective analysis of patients seen for 20 years (between 1983 and 2002). Individual case records were reviewed with regard to history, clinical, findings from colonoscopy, biopsies, small bowel enema, computerized tomography scan, treatment and outcome.RESULTS: Seventy-seven patients with Crohn's disease were revisited, 13% presented the disease in the first 10 years and 87% over the last 10 years. Thirty-three patients (42.9%) were males and 44 (57.1%) were females. Age ranged from 11-70 years (mean of 25.3+11.3 years). Ninety-two (92%) were Saudi. The mean duration of symptoms was 26+34.7 mo. The mean annual incidence of the disease over the first 10 years was 0.32:100 000 and 1.66:100 000 over the last 10 years with a total mean annual incidence of 0.94:100 000 over the last 20 years. The chief clinical features included abdominal pain, diarrhea, weight loss,anorexia, rectal bleeding and palpable mass. Colonoscopic findings were abnormal in 58 patients (76%) showing mostly ulcerations and inflammation of the colon. Eighty nine percent of patients showed nonspecific inflammation with chronic inflammatory cells and half of these patients revealed the presence of granulomas and granulations on bowel biopsies. Similarly, 69 (89%) of small bowel enema results revealed ulcerations (49%), narrowing of the bowel lumen (42%), mucosal thickening (35%) and cobblestone appearance (35%). CT scan showed abnormality in 68 (88%) of patients with features of thickened loops (66%) and lymphadenopathy (37%). Seventy-eight percent of patients had small and large bowel disease, 16% had small bowel involvement and only 6% had colitis alone. Of the total 55 (71%) patients treated with steroids at some point in their disease history, a satisfactory response to therapy was seen in 28 patients (51%) while 27 (49%) showed recurrences of the conditio展开更多
Increasing plant density and improving N fertilizer rate along with the use of high density-tolerant genotypes would lead to maximizing maize(Zea mays L.) grain productivity per unit land area. The objective of this i...Increasing plant density and improving N fertilizer rate along with the use of high density-tolerant genotypes would lead to maximizing maize(Zea mays L.) grain productivity per unit land area. The objective of this investigation was to match the functions of optimum plant density and adequate nitrogen fertilizer application to produce the highest possible yields per unit area with the greatest maize genotype efficiency. Six maize inbred lines differing in tolerance to low N and high density(D) [three tolerant(T); L-17, L-18, L-53,and three sensitive(S); L-29, L-54, L-55] were chosen for diallel crosses. Parents and crosses were evaluated in the 2012 and 2013 seasons under three plant densities: low(47,600),medium(71,400), and high(95,200) plants ha-1and three N fertilization rates: low(no N addition), medium(285 kg N ha-1) and high(570 kg N ha-1). The T × T crosses were superior to the S × S and T × S crosses under the low N–high D environment in most studied traits across seasons. The relationships between the nine environments and grain yield per hectare(GYPH) showed near-linear regression functions for inbreds L54, L29, and L55 and hybrids L18 × L53 and L18 × L55 with the highest GYPH at a density of47,600 plants ha-1and N rate of 570 kg N ha-1and a curvilinear relationship for inbreds L17, L18, and L53 and the rest of the hybrids with the highest GYPH at a density of95,200 plants ha-1combined with an N rate of 570 kg N ha-1. Cross L17 × L54 gave the highest grain yield in this study under both high N–high-D(19.9 t ha-1) and medium N–high-D environments(17.6 t ha-1).展开更多
Objective:To look into the glucose tolerance test characteristics and determine complications in non-gestational diabetes pregnant subjects.Methods:From 2006 to 2009 all non-gestational diabetes mellitus(non-CDM)pregn...Objective:To look into the glucose tolerance test characteristics and determine complications in non-gestational diabetes pregnant subjects.Methods:From 2006 to 2009 all non-gestational diabetes mellitus(non-CDM)pregnant women who delivered macrosomia at the North Australia's Townsville Hospital were retrospectively reviewed by extracting data from clinical record.Glucose tolerance tests results were analysed in the light of an earlier diagnosis of non-GDM.Results:Ninety-one non-CDM mothers with macrosomia were studied and compared with 41normoglycemic subjects without macrosomia.Of the subjects with non-GDM macrosomia,45(49.4%)had normal SO g glucose challenge test(GCT)without further testing,another 8(8.8%)had abnormal GCT but normal 75 g oral glucose tolerance test(OGTT).A total of 4(4.4%)subjects had normal GCT and OGTT.Interestingly.14 out of 16(87.5%)subjects who were tested with OGTT owing to past history of macrosomia had normal results but delivered macrosomic babies.Only 12 subjects had both GCT and OGTT,the rest of the cohort had either of the two tests.Subjects with non-CDM macrosomia had higher frequency of neonatal hypoglycaemia 34%as compared to 10%in nonmacrosomic babies(P=0.003).Other feto-maternal complications were similar in both groups.Conclussions:No significant pattern of glucose tolerance characteristics was identified in nonGDM mothers with macrosomic babies.In spite of being normoglycemic significant neonatal hypoglycaemia was recorded in non-GDM macrosomic babies.Further prospective studies on a larger population are needed to verify our findings.展开更多
New fluorine substituted 6-(5’-fluoro-2’-triphenylphosphiniminophenyl) 3-thioxo-1,2,4-triazin-5 (2H, 4H) one (2) was obtained via Wittig’s reaction of the corresponding 6-(5’-fluoro-2’-amino-phenyl)-3-thioxo-1,2,...New fluorine substituted 6-(5’-fluoro-2’-triphenylphosphiniminophenyl) 3-thioxo-1,2,4-triazin-5 (2H, 4H) one (2) was obtained via Wittig’s reaction of the corresponding 6-(5’-fluoro-2’-amino-phenyl)-3-thioxo-1,2,4-triazinone (1). Behavior of compound 2 towards alkylating agents and/or oxidizing agents was studied were, N-hydroxyl (3), Mannich base (4,5), S-alkyl (6,7,8) and thiazolo [3,2-b][1,2,4] triazinones (10-14) and or 3-disulfide (18), 3-sulfonic acid 19 and 1,2,4-triazin-3,5-Dionne (20) derivatives obtained. Structures of the new products are established by elemental and spectral data. The new targets obtained screened as Molluscicidalagents against Biomophlaria Alexandrina snails responsible for Bilharziasis diseases, in compare with Baylucide as standard drug.展开更多
BACKGROUND A cure for Helicobacter pylori(H.pylori)remains a problem of global concern.The prevalence of antimicrobial resistance is widely rising and becoming a challenging issue worldwide.Optimizing sequential thera...BACKGROUND A cure for Helicobacter pylori(H.pylori)remains a problem of global concern.The prevalence of antimicrobial resistance is widely rising and becoming a challenging issue worldwide.Optimizing sequential therapy seems to be one of the most attractive strategies in terms of efficacy,tolerability and cost.The most common sequential therapy consists of a dual therapy[proton-pump inhibitors(PPIs)and amoxicillin]for the first period(5 to 7 d),followed by a triple therapy for the second period(PPI,clarithromycin and metronidazole).PPIs play a key role in maintaining a gastric pH at a level that allows an optimal efficacy of antibiotics,hence the idea of using new generation molecules.This open-label prospective study randomized 328 patients with confirmed H.pylori infection into three groups(1:1:1):The first group received quadruple therapy consisting of twice-daily(bid)omeprazole 20 mg,amoxicillin 1 g,clarith-romycin 500 mg and metronidazole 500 mg for 10 d(QT-10),the second group received a 14 d quadruple therapy following the same regimen(QT-14),and the third group received an optimized sequential therapy consisting of bid rabe-prazole 20 mg plus amoxicillin 1 g for 7 d,followed by bid rabeprazole 20 mg,clarithromycin 500 mg and metronidazole 500 mg for the next 7 d(OST-14).AEs were recorded throughout the study,and the H.pylori eradication rate was determined 4 to 6 wk after the end of treatment,using the 13C urea breath test.RESULTS In the intention-to-treat and per-protocol analysis,the eradication rate was higher in the OST-14 group compared to the QT-10 group:(93.5%,85.5%P=0.04)and(96.2%,89.5%P=0.03)respectively.However,there was no statist-ically significant difference in eradication rates between the OST-14 and QT-14 groups:(93.5%,91.8%P=0.34)and(96.2%,94.4%P=0.35),respectively.The overall incidence of AEs was significantly lower in the OST-14 group(P=0.01).Furthermore,OST-14 was the most cost-effective among the three groups.CONCLUSION The optimized 14-d sequential therapy is a safe and effective alt展开更多
There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to i...There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to identify the activity improvement and discover that Ni sites act as a host to attract Fe(Ⅲ)to form Fe(Ni)(Ⅲ)binary centres,which serve as the dynamic sites to promote OER activity and stability by cyclical formation of intermediates(Fe(Ⅲ)→Fe(Ni)(Ⅲ)→Fe(Ni)-OH→Fe(Ni)-O→Fe(Ni)OOH→Fe(Ⅲ))at the electrode/electrolyte interface to emit O_(2).Additionally,some ions(Co(Ⅱ),Ni(Ⅱ),and Cr(Ⅲ))can also be the active sites to catalyze the OER process on a variety of electrodes.The Fe(Ⅲ)-catalyzed overall water-splitting electrolyzer comprising bare Ni foam as the anode and Pt/Ni-Mo as the cathode demonstrates robust stability for 1600 h at 1000 mA cm^(-2)@~1.75 V.The results provide insights into the ioncatalyzed effects boosting OER performance.展开更多
Light detection and ranging(LiDAR)has contributed immensely to forest mapping and 3D tree modelling.From the perspective of data acquisition,the integration of LiDAR data from different platforms would enrich forest i...Light detection and ranging(LiDAR)has contributed immensely to forest mapping and 3D tree modelling.From the perspective of data acquisition,the integration of LiDAR data from different platforms would enrich forest information at the tree and plot levels.This research develops a general framework to integrate ground-based and UAV-LiDAR(ULS)data to better estimate tree parameters based on quantitative structure modelling(QSM).This is accomplished in three sequential steps.First,the ground-based/ULS LiDAR data were co-registered based on the local density peaks of the clustered canopy.Next,redundancy and noise were removed for the ground-based/ULS LiDAR data fusion.Finally,tree modeling and biophysical parameter retrieval were based on QSM.Experiments were performed for Backpack/Handheld/UAV-based multi-platform mobile LiDAR data of a subtropical forest,including poplar and dawn redwood species.Generally,ground-based/ULS LiDAR data fusion outperforms ground-based LiDAR with respect to tree parameter estimation compared to field data.The fusion-derived tree height,tree volume,and crown volume significantly improved by up to 9.01%,5.28%,and 18.61%,respectively,in terms of rRMSE.By contrast,the diameter at breast height(DBH)is the parameter that has the least benefits from fusion,and rRMSE remains approximately the same,because stems are already well sampled from ground data.Additionally,particularly for dense forests,the fusion-derived tree parameters were improved compared to those derived from ground-based LiDAR.Ground-based LiDAR can potentially be used to estimate tree parameters in low-stand-density forests,whereby the improvement owing to fusion is not significant.展开更多
目的模拟训练(simulation-based training,SBT)是一种有效的教育方法,广泛应用于包括肿瘤学在内的多种临床环境中。该文对肿瘤学中与SBT相关的研究进行了范围综述,全面了解SBT在提高医护人员技能方面的作用,从而提高护理质量和患者安全...目的模拟训练(simulation-based training,SBT)是一种有效的教育方法,广泛应用于包括肿瘤学在内的多种临床环境中。该文对肿瘤学中与SBT相关的研究进行了范围综述,全面了解SBT在提高医护人员技能方面的作用,从而提高护理质量和患者安全。方法根据Arksey和O’Malley提出的范围综述方法框架,在Medline、Scopus和Web of Science数据库中检索于2012年至2022年发表的,与SBT在提高肿瘤科医护人员技能方面的相关研究文献,仅纳入经过同行评审的英文或法语文献。由2名研究员独立进行文献的筛选、提取和分析。结果检索出1013篇文章,共纳入29篇文献。其中25篇文献侧重于非技术技能,如决策技能、沟通和团队合作技能以及认知能力;13篇文献侧重于技术技能。纳入文献研究结果表明,通过SBT项目,肿瘤科医护人员的技能得到了显著提高。其中14篇文献对SBT的应用进行了主观评估,9篇文献对其进行了客观评估,6篇文献采用了主观和客观相结合的评估方法。结论SBT是提高肿瘤科医护人员技能的有效方法,支持和推广SBT对提供高质量的医疗服务和确保患者安全至关重要。展开更多
Inulin is a prebiotic dietary fiber that plays an integral role in producing functional dairy products with improved health benefits. Therefore, the objectives of this study are as follows: extract and purify inulin f...Inulin is a prebiotic dietary fiber that plays an integral role in producing functional dairy products with improved health benefits. Therefore, the objectives of this study are as follows: extract and purify inulin from chicory roots and globe artichoke roots;evaluate the physicochemical, functional properties and functional groups of the purified inulin;determine the functional properties of chicory roots inulin-maltodextrin and globe artichoke roots inulin-maltodextrin and compare it with that of the commercial inulin;examine the impact of various inulin on physiochemical, microstructural, textural, sensory characteristics and as prebiotic dietary fiber on probiotic bacteria’s viability of stirred bio-yogurt. The characteristics of the microstructure were investigated by scanning electron microscopy and, Fourier transforms infrared spectroscopy to detect the functional group. The resulting inulin exhibited a high yield and purity along with enhanced functional properties. Stirred bio-yogurt fortified with chicory roots inulin or globe artichoke roots inulin showed enhanced physicochemical, microstructural, microbiological, and overall sensorial acceptability followed by chicory roots inulin-maltodextrin or globe artichoke roots inulin-maltodextrin and the commercial inulin as compared to the control. Stirred bio-yogurt samples can offer various health benefits and wide applications as supplement of prebiotic dietary fiber in dairy industry.展开更多
运用太阳能热泵系统为草莓温室供暖,能有效提升草莓的产量和品质。为探究温室内立体栽培的供暖特性,以及相匹配的太阳能热泵系统的供暖系数(coefficient of performance,COP),该文设计并搭建了太阳能热泵阶梯式供暖系统。以"京藏香...运用太阳能热泵系统为草莓温室供暖,能有效提升草莓的产量和品质。为探究温室内立体栽培的供暖特性,以及相匹配的太阳能热泵系统的供暖系数(coefficient of performance,COP),该文设计并搭建了太阳能热泵阶梯式供暖系统。以"京藏香"草莓为试材,分析了距离地面0.5、1.0、1.5及2.0 m不同阶梯高度的空间温度,对比了阶梯式供暖的太阳能温室和未供暖的普通温室内的草莓品质及产量。结果表明,在北亚热带低纬高原山地季风气候地区,冬季采用太阳能热泵系统为温室供暖的COP值在3.02~5.15之间。在太阳能温室内种植的草莓产量是普通温室产量的1.56倍,可溶性固形物含量的平均值达10.5%。在太阳能热泵系统阶梯式供暖的温室中,距离地面1.0~1.5 m高度范围内的供暖效果较好,且放置于1.0 m阶梯上的草莓与其他高度的草莓相比,产量最高品质最优,其单果最大值为32.3 g,可溶性固形物含量为12.5%,因此,采用阶梯式供暖的温室中,距离地面1.0 m高度的温度更适宜草莓生长需求。展开更多
cyanoacrylate and a mixture of 72% chromated glycerinwith hypertonic glucose solution in management ofgastric varices.METHODS： Ninety patients with gastric varicespresented to Endoscopy Unit of Ain Shams UniversityHo...cyanoacrylate and a mixture of 72% chromated glycerinwith hypertonic glucose solution in management ofgastric varices.METHODS： Ninety patients with gastric varicespresented to Endoscopy Unit of Ain Shams UniversityHospital were included. They were randomly allocatedinto three groups; each group included 30 patients treatedwith intravariceal sclerosant injections in biweeklysessions till complete obturation of gastric varices;Group I （n-butyl-2-cyanoacrylate; Histoacryl？）, GroupII （iso-amyl-2-cyanoacrylate; Amcrylate？） and GroupIII （mixture of 72% chromated glycerin; Scleremo？with glucose solution 25%）. All the procedures wereperformed electively without active bleeding. Recruitedpatients were followed up for 3 mo.RESULTS： 26% of Scleremo group had bleeding duringpuncture vs 3.3% in each of the other two groups withsignificant difference, （P 〈 0.05）. None of Scleremogroup had needle obstruction vs 13.3% in each of theother two groups with no significant difference, （P 〉0.05）. Rebleeding occurred in 13.3% of Histoacryl andAmcrylate groups vs 0% in Scleremo group with nosignificant difference. The in hospital mortality was 6.6%in both Histoacryl and Amcrylate groups, while it was0% in Scleremo group with no significant difference. Inthe first and second sessions, the amount of Scleremoneeded for obturation was significantly high, while the amount of Histoacryl was significantly low. Scleremo was the less costly of the two treatments. CONCLUSION： All used sclerosant substances showed efficacy and success in management of gastric varices with no significant differences except in total amount,cost and bleeding during puncture.展开更多
Recently,inverted T-beams have been used in reinforced concrete(RC)bridges to support transverse precast stringers.Inverted T-beams,contrary to practice with conventional beams,are loaded on the flanges upper surface....Recently,inverted T-beams have been used in reinforced concrete(RC)bridges to support transverse precast stringers.Inverted T-beams,contrary to practice with conventional beams,are loaded on the flanges upper surface.This loading configuration causes hanger failure due to the generation of vertical tensile stresses near the bottom of the web.The key purpose of this study is to investigate the efficiency of vertical external prestressing stainless-steel bars in mitigating non-ductile hanger failure in reinforced concrete inverted T-beams.An experimental study on six inverted-T beams,including two un-strengthened specimens,was carried out.The study showed that the value of the prestressing level had a considerable impact on the performance of hanger mechanism in relation to crack pattern,ultimate loads,cracking behavior,load-deflection,strains,and ductility.The experimental results indicated that the suggested method for strengthening inverted T-beams had efficacy in reducing the seriousness of the non-ductile hanger failure and resulted in a strength increase of up to 53% when compared to that of the un-strengthened specimen.Additionally,two analytical models for estimating the hanger capacity and the average crack width of the strengthened RC inverted T-beams were proposed.The models that were proposed exhibited a high degree of agreement with the experimental results.展开更多
Edge detection is the process of determining where boundaries of objects fall within an image. So far, several standard operators-based methods have been widely used for edge detection. However, due to inherent qualit...Edge detection is the process of determining where boundaries of objects fall within an image. So far, several standard operators-based methods have been widely used for edge detection. However, due to inherent quality of images, these methods prove ineffective if they are applied without any preprocessing. In this paper, an image preprocessing approach has been adopted in order to get certain parameters that are useful to perform better edge detection with the standard operators-based edge detection methods. The proposed preprocessing approach involves computation of the histogram, finding out the total number of peaks and suppressing irrelevant peaks. From the intensity values corresponding to relevant peaks, threshold values are obtained. From these threshold values, optimal multilevel thresholds are calculated using the Otsu method, then multilevel image segmentation is carried out. Finally, a standard edge detection method can be applied to the resultant segmented image. Simulation results are presented to show that our preprocessed approach when used with a standard edge detection method enhances its performance. It has been also shown that applying wavelet edge detection method to the segmented images, generated through our preprocessing approach, yields the superior performance among other standard edge detection methods.展开更多
By optimal sizing of a wind/photovoltaic hybrid renewable-energy(RE)system,trimming the surplus capacity to reduce the fluctuations in the electricity supplied to the grid,and using it to produce green hydrogen throug...By optimal sizing of a wind/photovoltaic hybrid renewable-energy(RE)system,trimming the surplus capacity to reduce the fluctuations in the electricity supplied to the grid,and using it to produce green hydrogen through electrolysis,a stable output with maximum possible capacity factor(CF)is generated to maintain the electricity grid stability.Simultaneously,the trimmed energy is used in a secondary conversion path that minimizes the weighted average cost of the energy generated from the entire plant.This surplus power-to-gas conversion allows the use of green hydrogen to produce electricity,methanol,or ammonia subject to the resource availability,site characteristics,and financial feasibility.Based on robust site selection criteria,the best performance is obtained at two sites:Ras Ghareb and Minya,achieving the lowest energy cost with some variance in their performance.For the Ras Ghareb site,the optimally sized RE plant provided the grid with a quasi-steady capacity of 423 MW with a CF of 80.04%and was capable of injecting 2965.8648 GWh throughout the year with the lowest cost of 2.4355¢/kWh.A surplus of 3.9%of the total energy produced from the plant was directed to produce 1922-ton H_(2)/year,achieving the lowest cost of hydrogen production of$1.9745/kg H_(2).For the other selected site,Minya,the clipped energy is used to produce 3330.47-ton H_(2)/year with an optimized lowest cost of$3.5268/kg H_(2).The difference in hydrogen costs was attributed to the number of full operating hours of the electrolyser in both sites.The cost is mainly affected by the electricity price and the electrolyser cost.With both tending to decrease,future forecasts show hydrogen cost reductions.展开更多
基金support of Dr. Azza M. Kamal, Biochemistry Dept, Animal Health Research Institute, Dokki 12618, Giza, Egypt
文摘Our trial was conducted to study the effects of formic acid(FA) and potassium di-formate(KDF) in broiler ration on performance, carcass traits, blood biochemical, intestinal microbial load, histological picture of intestine and immune parameters of broilers. In this study 360 one-day-old broiler chicks were divided to 3 groups with 3 replicates of 40 chicks each. The trial continued for 35 days. The control group was fed only basal diet(G1). Group 2(G2) were fed basal diet supplemented with FA(5 g/kg diet), and group 3(G3) received basal diet supplemented with KDF(5 g/kg diet). The results showed that both FA and KDF significantly increased body weight gain(BWG), dressing percentage of broilers and significantly decreased feed conversion ratio(FCR)(P < 0.05). The highest percent of breast and thigh was observed in G3. The improvement in villus height was observed in G2 and G3 compared with the control one, and the highest was in G3. The results evidence that the using of FA or KDF in broiler feeds have significant effects on performance, immune parameters, and gut health without having any significant effects on blood biochemical. However, KDF is more effective than FA as little amount of FA reaches the small intestine due to metabolism and absorption, whereas KDF permits a proportion of FA to pass through the fore-gut intact and enter the small intestinal tract. In addition, FA has a strong odor and corrosiveness to gastrointestinal tract which limits its use.
文摘CDX2 is a nuclear homeobox transcription factor that belongs to the caudalrelated family of CDX homeobox genes. The gene encoding CDX2 is a nonclustered hexapeptide located on chromosome 13q12-13. Homeobox genes play an essential role in the control of normal embryonic development. CDX2 is crucial for axial patterning of the alimentary tract during embryonic development and is involved in the processes of intestinal cell proliferation, differentiation, adhesion, and apoptosis. It is considered specif ic for enterocytes and has been used for the diagnosis of primary and metastatic colorectal adenocarcinoma. CDX2 expression has been reported to be organ specif ic and is normally expressed throughout embryonic and postnatal life within the nuclei of epithelial cells of the alimentary tract from the proximal duodenum to the distal rectum. In this review, the authors elaborate on the diagnostic utility of CDX2 in gastrointestinal tumors and other neoplasms with intestinal differentiation. Limitations with its use as the sole predictor of a gastrointestinal origin of metastatic carcinomas are also discussed.
文摘Tumor necrosis factor-alpha (TNF-α) is an important cytokine in generating an immune response against infection with hepatitis C virus (HCV). The functions of TNF-α may be altered by single-nucleotide polymorphisms (SNPs) in its gene structure. We hypothesized that SNPs in TNF-α may be important in determining the outcome of an HCV infection. To test this hypothesis, we investigated the role of the polymorphism -308G/A, which is located in the promoter region of the TNF-α gene, in the progression of HCV infection in Egyptian patients using a quantitative real-time polymerase chain reaction (qRT-PCR). The distribution of this polymorphism and its impact on the serum level of TNF-α was compared between 90 HCV-infected patients [45 with HCV-induced cirrhosis and 45 with HCV-related hepatocellular carcinoma (HCC)] and 45 healthy Egyptian volunteers without any history of liver disease. Our results showed that at the TNF-α -308 position, the G/G allele was most common (78.5% ) in the study population, with the G/A and A/A alleles occurring less frequently (13.3% and 8.1% , respectively). Frequencies of G/G, G/A, and A/A genotypes were 87%, 7%, and 6% in patients with liver cirrhosis and were 94% , 4% , and 2% in patients with HCC, respectively. Serum levels of TNF-α were significantly higher in HCV-infected patients than in healthy controls, indicating that the TNF-α -308 polymorphism does not influence the production of TNF-α. The serum level of TNF-α was positively correlated with HCV infection. Taken together, these findings suggest that the TNF-α -308 polymorphism may not be a host genetic factor associated with the severity of HCV infection, but may be an independent risk factor for HCC.
文摘Sodium-glucose cotransporter-2 inhibitors (SGLT-2 inhibitors) have transformed diabetes management by targeting renal glucose reabsorption. Designed initially as antidiabetic agents, their ability to lower blood glucose levels independently of insulin is well-documented. Beyond glycemic control, emerging research has unveiled their profound cardiorenal benefits. By inhibiting SGLT-2 protein, these drugs enhance glucose excretion in urine, reducing blood glucose levels. This mechanism has translated into significant cardiovascular and renal protection, establishing SGLT-2 inhibitors as pivotal in managing not only diabetes but also cardiovascular and renal diseases. Recent studies have illuminated the broader therapeutic potential of SGLT-2 inhibitors beyond diabetes. Evidence indicates their efficacy in managing heart failure, chronic kidney disease (CKD), and cardiovascular complications in individuals with or without diabetes. This expanded therapeutic landscape has catalyzed a paradigm shift in SGLT-2 inhibitor use, positioning them as key agents in the cardiorenal metabolic continuum. Moreover, their role in the secondary prevention of cardiovascular events and slowing CKD progression in T2DM patients has garnered considerable attention. This consensus-based review aims to offer practical guidance in an algorithmic approach to primary care healthcare professionals to optimize SGLT-2 inhibitors utilization and maximize their benefits. The review seeks to empower clinicians to effectively manage patients who may benefit from SGLT-2 inhibitor therapy by addressing common initiation barriers and optimizing treatment strategies. Additionally, it aims to raise awareness among primary care physicians regarding the multifaceted benefits of these medications and overcome clinical inertia in their adoption into routine clinical practice.
文摘AIM: To know the epidemiology and outcome of Crohn's disease at King Khalid University Hospital, Riyadh, Saudi Arabia and to compare the results from other world institutions.METHODS: A retrospective analysis of patients seen for 20 years (between 1983 and 2002). Individual case records were reviewed with regard to history, clinical, findings from colonoscopy, biopsies, small bowel enema, computerized tomography scan, treatment and outcome.RESULTS: Seventy-seven patients with Crohn's disease were revisited, 13% presented the disease in the first 10 years and 87% over the last 10 years. Thirty-three patients (42.9%) were males and 44 (57.1%) were females. Age ranged from 11-70 years (mean of 25.3+11.3 years). Ninety-two (92%) were Saudi. The mean duration of symptoms was 26+34.7 mo. The mean annual incidence of the disease over the first 10 years was 0.32:100 000 and 1.66:100 000 over the last 10 years with a total mean annual incidence of 0.94:100 000 over the last 20 years. The chief clinical features included abdominal pain, diarrhea, weight loss,anorexia, rectal bleeding and palpable mass. Colonoscopic findings were abnormal in 58 patients (76%) showing mostly ulcerations and inflammation of the colon. Eighty nine percent of patients showed nonspecific inflammation with chronic inflammatory cells and half of these patients revealed the presence of granulomas and granulations on bowel biopsies. Similarly, 69 (89%) of small bowel enema results revealed ulcerations (49%), narrowing of the bowel lumen (42%), mucosal thickening (35%) and cobblestone appearance (35%). CT scan showed abnormality in 68 (88%) of patients with features of thickened loops (66%) and lymphadenopathy (37%). Seventy-eight percent of patients had small and large bowel disease, 16% had small bowel involvement and only 6% had colitis alone. Of the total 55 (71%) patients treated with steroids at some point in their disease history, a satisfactory response to therapy was seen in 28 patients (51%) while 27 (49%) showed recurrences of the conditio
文摘Increasing plant density and improving N fertilizer rate along with the use of high density-tolerant genotypes would lead to maximizing maize(Zea mays L.) grain productivity per unit land area. The objective of this investigation was to match the functions of optimum plant density and adequate nitrogen fertilizer application to produce the highest possible yields per unit area with the greatest maize genotype efficiency. Six maize inbred lines differing in tolerance to low N and high density(D) [three tolerant(T); L-17, L-18, L-53,and three sensitive(S); L-29, L-54, L-55] were chosen for diallel crosses. Parents and crosses were evaluated in the 2012 and 2013 seasons under three plant densities: low(47,600),medium(71,400), and high(95,200) plants ha-1and three N fertilization rates: low(no N addition), medium(285 kg N ha-1) and high(570 kg N ha-1). The T × T crosses were superior to the S × S and T × S crosses under the low N–high D environment in most studied traits across seasons. The relationships between the nine environments and grain yield per hectare(GYPH) showed near-linear regression functions for inbreds L54, L29, and L55 and hybrids L18 × L53 and L18 × L55 with the highest GYPH at a density of47,600 plants ha-1and N rate of 570 kg N ha-1and a curvilinear relationship for inbreds L17, L18, and L53 and the rest of the hybrids with the highest GYPH at a density of95,200 plants ha-1combined with an N rate of 570 kg N ha-1. Cross L17 × L54 gave the highest grain yield in this study under both high N–high-D(19.9 t ha-1) and medium N–high-D environments(17.6 t ha-1).
基金Supported in part by funds from Australia's James Cook University research infrastructure block grant(Grant No.RIBG 09-2009)
文摘Objective:To look into the glucose tolerance test characteristics and determine complications in non-gestational diabetes pregnant subjects.Methods:From 2006 to 2009 all non-gestational diabetes mellitus(non-CDM)pregnant women who delivered macrosomia at the North Australia's Townsville Hospital were retrospectively reviewed by extracting data from clinical record.Glucose tolerance tests results were analysed in the light of an earlier diagnosis of non-GDM.Results:Ninety-one non-CDM mothers with macrosomia were studied and compared with 41normoglycemic subjects without macrosomia.Of the subjects with non-GDM macrosomia,45(49.4%)had normal SO g glucose challenge test(GCT)without further testing,another 8(8.8%)had abnormal GCT but normal 75 g oral glucose tolerance test(OGTT).A total of 4(4.4%)subjects had normal GCT and OGTT.Interestingly.14 out of 16(87.5%)subjects who were tested with OGTT owing to past history of macrosomia had normal results but delivered macrosomic babies.Only 12 subjects had both GCT and OGTT,the rest of the cohort had either of the two tests.Subjects with non-CDM macrosomia had higher frequency of neonatal hypoglycaemia 34%as compared to 10%in nonmacrosomic babies(P=0.003).Other feto-maternal complications were similar in both groups.Conclussions:No significant pattern of glucose tolerance characteristics was identified in nonGDM mothers with macrosomic babies.In spite of being normoglycemic significant neonatal hypoglycaemia was recorded in non-GDM macrosomic babies.Further prospective studies on a larger population are needed to verify our findings.
文摘New fluorine substituted 6-(5’-fluoro-2’-triphenylphosphiniminophenyl) 3-thioxo-1,2,4-triazin-5 (2H, 4H) one (2) was obtained via Wittig’s reaction of the corresponding 6-(5’-fluoro-2’-amino-phenyl)-3-thioxo-1,2,4-triazinone (1). Behavior of compound 2 towards alkylating agents and/or oxidizing agents was studied were, N-hydroxyl (3), Mannich base (4,5), S-alkyl (6,7,8) and thiazolo [3,2-b][1,2,4] triazinones (10-14) and or 3-disulfide (18), 3-sulfonic acid 19 and 1,2,4-triazin-3,5-Dionne (20) derivatives obtained. Structures of the new products are established by elemental and spectral data. The new targets obtained screened as Molluscicidalagents against Biomophlaria Alexandrina snails responsible for Bilharziasis diseases, in compare with Baylucide as standard drug.
文摘BACKGROUND A cure for Helicobacter pylori(H.pylori)remains a problem of global concern.The prevalence of antimicrobial resistance is widely rising and becoming a challenging issue worldwide.Optimizing sequential therapy seems to be one of the most attractive strategies in terms of efficacy,tolerability and cost.The most common sequential therapy consists of a dual therapy[proton-pump inhibitors(PPIs)and amoxicillin]for the first period(5 to 7 d),followed by a triple therapy for the second period(PPI,clarithromycin and metronidazole).PPIs play a key role in maintaining a gastric pH at a level that allows an optimal efficacy of antibiotics,hence the idea of using new generation molecules.This open-label prospective study randomized 328 patients with confirmed H.pylori infection into three groups(1:1:1):The first group received quadruple therapy consisting of twice-daily(bid)omeprazole 20 mg,amoxicillin 1 g,clarith-romycin 500 mg and metronidazole 500 mg for 10 d(QT-10),the second group received a 14 d quadruple therapy following the same regimen(QT-14),and the third group received an optimized sequential therapy consisting of bid rabe-prazole 20 mg plus amoxicillin 1 g for 7 d,followed by bid rabeprazole 20 mg,clarithromycin 500 mg and metronidazole 500 mg for the next 7 d(OST-14).AEs were recorded throughout the study,and the H.pylori eradication rate was determined 4 to 6 wk after the end of treatment,using the 13C urea breath test.RESULTS In the intention-to-treat and per-protocol analysis,the eradication rate was higher in the OST-14 group compared to the QT-10 group:(93.5%,85.5%P=0.04)and(96.2%,89.5%P=0.03)respectively.However,there was no statist-ically significant difference in eradication rates between the OST-14 and QT-14 groups:(93.5%,91.8%P=0.34)and(96.2%,94.4%P=0.35),respectively.The overall incidence of AEs was significantly lower in the OST-14 group(P=0.01).Furthermore,OST-14 was the most cost-effective among the three groups.CONCLUSION The optimized 14-d sequential therapy is a safe and effective alt
基金financially supported by the 2022 Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(STKJ202209077 and STKJ202209083)the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2019(GDUPS2019)the City University of Hong Kong Strategic Research Grant(SRG)(7005505)。
文摘There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to identify the activity improvement and discover that Ni sites act as a host to attract Fe(Ⅲ)to form Fe(Ni)(Ⅲ)binary centres,which serve as the dynamic sites to promote OER activity and stability by cyclical formation of intermediates(Fe(Ⅲ)→Fe(Ni)(Ⅲ)→Fe(Ni)-OH→Fe(Ni)-O→Fe(Ni)OOH→Fe(Ⅲ))at the electrode/electrolyte interface to emit O_(2).Additionally,some ions(Co(Ⅱ),Ni(Ⅱ),and Cr(Ⅲ))can also be the active sites to catalyze the OER process on a variety of electrodes.The Fe(Ⅲ)-catalyzed overall water-splitting electrolyzer comprising bare Ni foam as the anode and Pt/Ni-Mo as the cathode demonstrates robust stability for 1600 h at 1000 mA cm^(-2)@~1.75 V.The results provide insights into the ioncatalyzed effects boosting OER performance.
基金supported by the National Natural Science Foundation of China(Project No.42171361)the Research Grants Council of the Hong Kong Special Administrative Region,China,under Project PolyU 25211819the Hong Kong Polytechnic University under Projects 1-ZE8E and 1-ZVN6.
文摘Light detection and ranging(LiDAR)has contributed immensely to forest mapping and 3D tree modelling.From the perspective of data acquisition,the integration of LiDAR data from different platforms would enrich forest information at the tree and plot levels.This research develops a general framework to integrate ground-based and UAV-LiDAR(ULS)data to better estimate tree parameters based on quantitative structure modelling(QSM).This is accomplished in three sequential steps.First,the ground-based/ULS LiDAR data were co-registered based on the local density peaks of the clustered canopy.Next,redundancy and noise were removed for the ground-based/ULS LiDAR data fusion.Finally,tree modeling and biophysical parameter retrieval were based on QSM.Experiments were performed for Backpack/Handheld/UAV-based multi-platform mobile LiDAR data of a subtropical forest,including poplar and dawn redwood species.Generally,ground-based/ULS LiDAR data fusion outperforms ground-based LiDAR with respect to tree parameter estimation compared to field data.The fusion-derived tree height,tree volume,and crown volume significantly improved by up to 9.01%,5.28%,and 18.61%,respectively,in terms of rRMSE.By contrast,the diameter at breast height(DBH)is the parameter that has the least benefits from fusion,and rRMSE remains approximately the same,because stems are already well sampled from ground data.Additionally,particularly for dense forests,the fusion-derived tree parameters were improved compared to those derived from ground-based LiDAR.Ground-based LiDAR can potentially be used to estimate tree parameters in low-stand-density forests,whereby the improvement owing to fusion is not significant.
文摘目的模拟训练(simulation-based training,SBT)是一种有效的教育方法,广泛应用于包括肿瘤学在内的多种临床环境中。该文对肿瘤学中与SBT相关的研究进行了范围综述,全面了解SBT在提高医护人员技能方面的作用,从而提高护理质量和患者安全。方法根据Arksey和O’Malley提出的范围综述方法框架,在Medline、Scopus和Web of Science数据库中检索于2012年至2022年发表的,与SBT在提高肿瘤科医护人员技能方面的相关研究文献,仅纳入经过同行评审的英文或法语文献。由2名研究员独立进行文献的筛选、提取和分析。结果检索出1013篇文章,共纳入29篇文献。其中25篇文献侧重于非技术技能,如决策技能、沟通和团队合作技能以及认知能力;13篇文献侧重于技术技能。纳入文献研究结果表明,通过SBT项目,肿瘤科医护人员的技能得到了显著提高。其中14篇文献对SBT的应用进行了主观评估,9篇文献对其进行了客观评估,6篇文献采用了主观和客观相结合的评估方法。结论SBT是提高肿瘤科医护人员技能的有效方法,支持和推广SBT对提供高质量的医疗服务和确保患者安全至关重要。
文摘Inulin is a prebiotic dietary fiber that plays an integral role in producing functional dairy products with improved health benefits. Therefore, the objectives of this study are as follows: extract and purify inulin from chicory roots and globe artichoke roots;evaluate the physicochemical, functional properties and functional groups of the purified inulin;determine the functional properties of chicory roots inulin-maltodextrin and globe artichoke roots inulin-maltodextrin and compare it with that of the commercial inulin;examine the impact of various inulin on physiochemical, microstructural, textural, sensory characteristics and as prebiotic dietary fiber on probiotic bacteria’s viability of stirred bio-yogurt. The characteristics of the microstructure were investigated by scanning electron microscopy and, Fourier transforms infrared spectroscopy to detect the functional group. The resulting inulin exhibited a high yield and purity along with enhanced functional properties. Stirred bio-yogurt fortified with chicory roots inulin or globe artichoke roots inulin showed enhanced physicochemical, microstructural, microbiological, and overall sensorial acceptability followed by chicory roots inulin-maltodextrin or globe artichoke roots inulin-maltodextrin and the commercial inulin as compared to the control. Stirred bio-yogurt samples can offer various health benefits and wide applications as supplement of prebiotic dietary fiber in dairy industry.
文摘cyanoacrylate and a mixture of 72% chromated glycerinwith hypertonic glucose solution in management ofgastric varices.METHODS： Ninety patients with gastric varicespresented to Endoscopy Unit of Ain Shams UniversityHospital were included. They were randomly allocatedinto three groups; each group included 30 patients treatedwith intravariceal sclerosant injections in biweeklysessions till complete obturation of gastric varices;Group I （n-butyl-2-cyanoacrylate; Histoacryl？）, GroupII （iso-amyl-2-cyanoacrylate; Amcrylate？） and GroupIII （mixture of 72% chromated glycerin; Scleremo？with glucose solution 25%）. All the procedures wereperformed electively without active bleeding. Recruitedpatients were followed up for 3 mo.RESULTS： 26% of Scleremo group had bleeding duringpuncture vs 3.3% in each of the other two groups withsignificant difference, （P 〈 0.05）. None of Scleremogroup had needle obstruction vs 13.3% in each of theother two groups with no significant difference, （P 〉0.05）. Rebleeding occurred in 13.3% of Histoacryl andAmcrylate groups vs 0% in Scleremo group with nosignificant difference. The in hospital mortality was 6.6%in both Histoacryl and Amcrylate groups, while it was0% in Scleremo group with no significant difference. Inthe first and second sessions, the amount of Scleremoneeded for obturation was significantly high, while the amount of Histoacryl was significantly low. Scleremo was the less costly of the two treatments. CONCLUSION： All used sclerosant substances showed efficacy and success in management of gastric varices with no significant differences except in total amount,cost and bleeding during puncture.
文摘Recently,inverted T-beams have been used in reinforced concrete(RC)bridges to support transverse precast stringers.Inverted T-beams,contrary to practice with conventional beams,are loaded on the flanges upper surface.This loading configuration causes hanger failure due to the generation of vertical tensile stresses near the bottom of the web.The key purpose of this study is to investigate the efficiency of vertical external prestressing stainless-steel bars in mitigating non-ductile hanger failure in reinforced concrete inverted T-beams.An experimental study on six inverted-T beams,including two un-strengthened specimens,was carried out.The study showed that the value of the prestressing level had a considerable impact on the performance of hanger mechanism in relation to crack pattern,ultimate loads,cracking behavior,load-deflection,strains,and ductility.The experimental results indicated that the suggested method for strengthening inverted T-beams had efficacy in reducing the seriousness of the non-ductile hanger failure and resulted in a strength increase of up to 53% when compared to that of the un-strengthened specimen.Additionally,two analytical models for estimating the hanger capacity and the average crack width of the strengthened RC inverted T-beams were proposed.The models that were proposed exhibited a high degree of agreement with the experimental results.
文摘Edge detection is the process of determining where boundaries of objects fall within an image. So far, several standard operators-based methods have been widely used for edge detection. However, due to inherent quality of images, these methods prove ineffective if they are applied without any preprocessing. In this paper, an image preprocessing approach has been adopted in order to get certain parameters that are useful to perform better edge detection with the standard operators-based edge detection methods. The proposed preprocessing approach involves computation of the histogram, finding out the total number of peaks and suppressing irrelevant peaks. From the intensity values corresponding to relevant peaks, threshold values are obtained. From these threshold values, optimal multilevel thresholds are calculated using the Otsu method, then multilevel image segmentation is carried out. Finally, a standard edge detection method can be applied to the resultant segmented image. Simulation results are presented to show that our preprocessed approach when used with a standard edge detection method enhances its performance. It has been also shown that applying wavelet edge detection method to the segmented images, generated through our preprocessing approach, yields the superior performance among other standard edge detection methods.
文摘By optimal sizing of a wind/photovoltaic hybrid renewable-energy(RE)system,trimming the surplus capacity to reduce the fluctuations in the electricity supplied to the grid,and using it to produce green hydrogen through electrolysis,a stable output with maximum possible capacity factor(CF)is generated to maintain the electricity grid stability.Simultaneously,the trimmed energy is used in a secondary conversion path that minimizes the weighted average cost of the energy generated from the entire plant.This surplus power-to-gas conversion allows the use of green hydrogen to produce electricity,methanol,or ammonia subject to the resource availability,site characteristics,and financial feasibility.Based on robust site selection criteria,the best performance is obtained at two sites:Ras Ghareb and Minya,achieving the lowest energy cost with some variance in their performance.For the Ras Ghareb site,the optimally sized RE plant provided the grid with a quasi-steady capacity of 423 MW with a CF of 80.04%and was capable of injecting 2965.8648 GWh throughout the year with the lowest cost of 2.4355¢/kWh.A surplus of 3.9%of the total energy produced from the plant was directed to produce 1922-ton H_(2)/year,achieving the lowest cost of hydrogen production of$1.9745/kg H_(2).For the other selected site,Minya,the clipped energy is used to produce 3330.47-ton H_(2)/year with an optimized lowest cost of$3.5268/kg H_(2).The difference in hydrogen costs was attributed to the number of full operating hours of the electrolyser in both sites.The cost is mainly affected by the electricity price and the electrolyser cost.With both tending to decrease,future forecasts show hydrogen cost reductions.
