17 research outputs found

    An Enhanced Approach of Image Steganographic Using Discrete Shearlet Transform and Secret Sharing

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                   في الآونة الأخيرة، جعل الإنترنت المستخدمين قادرين على نقل الوسائط الرقمية بطريقة أسهل. على الرغم من هذه السهولة للإنترنت، إلا أنه قد تؤدي إلى العديد من التهديدات التي تتعلق بسرية محتويات الوسائط المنقولة مثل مصادقة الوسائط والتحقق من تكاملها. لهذه الأسباب ، يتم استخدام أساليب إخفاء البيانات والتشفير لحماية محتويات الوسائط الرقمية. في هذه الورقة البحثية ، تم اقتراح طريقة معززة لإخفاء المعلومات بالصور مع التشفير المرئي. يتم تشفير الشعار السري (صورة ثنائية) بالحجم (128 × 128) عن طريق تطبيق التشفير البصري (2 out 2 share) لتوليد مشاركتين سريتين. أثناء عملية التضمين ، يتم تقسيم الصورة غطاء RGB بحجم (512 × 512) إلى ثلاث طبقات (الأحمر والأخضر والأزرق). يتم تحويل الطبقة الزرقاء باستخدام التحويل Shearlet المتقطع للحصول على معاملاتها. يتم تضمين المشاركة السرية الأولى في معاملات الطبقة الزرقاء المحولة للحصول على صورة الاخفاء. في عملية الاستخراج ، يتم استخراج المشاركة السرية الأولى من معاملات الطبقة الزرقاء لصورة الاخفاء وثم يتم تطبيق عملية XOR عليها مع المشاركة السرية الثانية لإنشاء الشعار السري الأصلي. وفقًا للنتائج التجريبية ، فإن الطريقة المقترحة قد حققت افضل نسبة من عدم الوضوح لصورة الاخفاء بقدرة الحمولة الصافية تساوي (1 bpp). أصبح الشعار السري أكثر أمانًا باستخدام التشفير المرئي (2 out 2 share)  والمشاركة السرية الثانية كمفتاح خاص ايضاً.  Recently, the internet has made the users able to transmit the digital media in the easiest manner. In spite of this facility of the internet, this may lead to several threats that are concerned with confidentiality of transferred media contents such as media authentication and integrity verification. For these reasons, data hiding methods and cryptography are used to protect the contents of digital media. In this paper, an enhanced method of image steganography combined with visual cryptography has been proposed. A secret logo (binary image) of size (128x128) is encrypted by applying (2 out 2 share) visual cryptography on it to generate two secret share. During the embedding process, a cover red, green, and blue (RGB) image of size (512x512) is divided into three layers (red, green and blue). The blue layer is transformed using Discrete Shearlet Transform (DST) to obtain its coefficients. The first secret share is embedded at the coefficients of transformed blue layer to obtain a stego image. At extraction process, the first secret share is extracted from the coefficients of blue layer of the stego image and XORed with the second secret share to generate the original secret logo. According to the experimental results, the proposed method is achieved better imperceptibility for the stego image with the payload capacity equal to (1 bpp). In addition, the secret logo becomes more secured using (2 out 2 share) visual cryptography and the second secret share as a private key

    Terrace Soil Suitability for Highway Construction: Case Study in Lesser Himalaya (CPEC Project E-35), North Pakistan

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    In this study, terrace soil investigation was carried out in project E-35 (phase-I) China-Pak Economic Corridor, Lesser Himalayas, North Pakistan. The methodology in current research is based on tests that include sieve analysis, plastic index, proctor, California Bearing Ratio, Los Angeles, sand equivalent and specific gravity. The results of these tests for different layers were compared with AASHTO and NHA specifications. The results show that the embankment, subgrade and subbase layers were composed of silt, sand and gravel, respectively while the aggregate base coarse was composed of sand, aggregate and less amount of fine clay material. The sieve analysis test shows that soil and aggregate base coarse has less clay with high silt, sandy material and index plastic to low plastic, which is appropriate for the construction. The California Bearing Ratio shows that the soil and aggregate base coarse have high load-bearing capacity. The Los Angeles abrasion reveal that the sub base and aggregate base coarse are resistive. The sand equivalent shows that aggregate base coarse has high sand material. The specific gravity illustrates that aggregate base coarse material is denser. The current study shows that terrace soil is suitable for the construction of the road in project E-35 (phase-I) China-Pak Economic Corridor

    Highly Selective Syngas/H2 Production via Partial Oxidation of CH4 Using (Ni, Co and Ni–Co)/ZrO2–Al2O3 Catalysts: Influence of Calcination Temperature

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    In this study, Ni, Co and Ni–Co catalysts supported on binary oxide ZrO2–Al2O3 were synthesized by sol-gel method and characterized by means of various analytical techniques such as XRD, BET, TPR, TPD, TGA, SEM, and TEM. This catalytic system was then tested for syngas respective H2 production via partial oxidation of methane at 700 °C and 800 °C. The influence of calcination temperatures was studied and their impact on catalytic activity and stability was evaluated. It was observed that increasing the calcination temperature from 550 °C to 800 °C and addition of ZrO2 to Al2O3 enhances Ni metal-support interaction. This increases the catalytic activity and sintering resistance. Furthermore, ZrO2 provides higher oxygen storage capacity and stronger Lewis basicity which contributed to coke suppression, eventually leading to a more stable catalyst. It was also observed that, contrary to bimetallic catalysts, monometallic catalysts exhibit higher activity with higher calcination temperature. At the same time, Co and Ni–Co-based catalysts exhibit higher activity than Ni-based catalysts which was not expected. The Co-based catalyst calcined at 800 °C demonstrated excellent stability over 24 h on stream. In general, all catalysts demonstrated high CH4 conversion and exceptionally high selectivity to H2 (~98%) at 700 °C

    Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial

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    Background: Tranexamic acid reduces surgical bleeding and reduces death due to bleeding in patients with trauma. Meta-analyses of small trials show that tranexamic acid might decrease deaths from gastrointestinal bleeding. We aimed to assess the effects of tranexamic acid in patients with gastrointestinal bleeding. Methods: We did an international, multicentre, randomised, placebo-controlled trial in 164 hospitals in 15 countries. Patients were enrolled if the responsible clinician was uncertain whether to use tranexamic acid, were aged above the minimum age considered an adult in their country (either aged 16 years and older or aged 18 years and older), and had significant (defined as at risk of bleeding to death) upper or lower gastrointestinal bleeding. Patients were randomly assigned by selection of a numbered treatment pack from a box containing eight packs that were identical apart from the pack number. Patients received either a loading dose of 1 g tranexamic acid, which was added to 100 mL infusion bag of 0·9% sodium chloride and infused by slow intravenous injection over 10 min, followed by a maintenance dose of 3 g tranexamic acid added to 1 L of any isotonic intravenous solution and infused at 125 mg/h for 24 h, or placebo (sodium chloride 0·9%). Patients, caregivers, and those assessing outcomes were masked to allocation. The primary outcome was death due to bleeding within 5 days of randomisation; analysis excluded patients who received neither dose of the allocated treatment and those for whom outcome data on death were unavailable. This trial was registered with Current Controlled Trials, ISRCTN11225767, and ClinicalTrials.gov, NCT01658124. Findings: Between July 4, 2013, and June 21, 2019, we randomly allocated 12 009 patients to receive tranexamic acid (5994, 49·9%) or matching placebo (6015, 50·1%), of whom 11 952 (99·5%) received the first dose of the allocated treatment. Death due to bleeding within 5 days of randomisation occurred in 222 (4%) of 5956 patients in the tranexamic acid group and in 226 (4%) of 5981 patients in the placebo group (risk ratio [RR] 0·99, 95% CI 0·82–1·18). Arterial thromboembolic events (myocardial infarction or stroke) were similar in the tranexamic acid group and placebo group (42 [0·7%] of 5952 vs 46 [0·8%] of 5977; 0·92; 0·60 to 1·39). Venous thromboembolic events (deep vein thrombosis or pulmonary embolism) were higher in tranexamic acid group than in the placebo group (48 [0·8%] of 5952 vs 26 [0·4%] of 5977; RR 1·85; 95% CI 1·15 to 2·98). Interpretation: We found that tranexamic acid did not reduce death from gastrointestinal bleeding. On the basis of our results, tranexamic acid should not be used for the treatment of gastrointestinal bleeding outside the context of a randomised trial

    Abstracts from the 3rd International Genomic Medicine Conference (3rd IGMC 2015)

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    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Highly Selective Syngas/H2 Production via Partial Oxidation of CH4 Using (Ni, Co and Ni–Co)/ZrO2–Al2O3 Catalysts: Influence of Calcination Temperature

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    In this study, Ni, Co and Ni–Co catalysts supported on binary oxide ZrO2–Al2O3 were synthesized by sol-gel method and characterized by means of various analytical techniques such as XRD, BET, TPR, TPD, TGA, SEM, and TEM. This catalytic system was then tested for syngas respective H2 production via partial oxidation of methane at 700 °C and 800 °C. The influence of calcination temperatures was studied and their impact on catalytic activity and stability was evaluated. It was observed that increasing the calcination temperature from 550 °C to 800 °C and addition of ZrO2 to Al2O3 enhances Ni metal-support interaction. This increases the catalytic activity and sintering resistance. Furthermore, ZrO2 provides higher oxygen storage capacity and stronger Lewis basicity which contributed to coke suppression, eventually leading to a more stable catalyst. It was also observed that, contrary to bimetallic catalysts, monometallic catalysts exhibit higher activity with higher calcination temperature. At the same time, Co and Ni–Co-based catalysts exhibit higher activity than Ni-based catalysts which was not expected. The Co-based catalyst calcined at 800 °C demonstrated excellent stability over 24 h on stream. In general, all catalysts demonstrated high CH4 conversion and exceptionally high selectivity to H2 (~98%) at 700 °C

    Catalytic Behaviour of Ce-Doped Ni Systems Supported on Stabilized Zirconia under Dry Reforming Conditions

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    Ni supported on bare and modified ZrO2 samples were synthesized using the incipient wet impregnation method. The t-ZrO2 phase was stabilized by incorporation of La2O3 into ZrO2. Moreover, the influence of CeO2-doping on the physico-chemical and catalytic properties under CO2 reforming conditions was probed. The characterization data of the investigated catalysts were obtained by using XRD, CO2/H2-TPD, BET, TPR, TPO, TGA, XPS and TEM characterization techniques. In the pristine Ni/Zr catalyst, the t-ZrO2 phase transformed into the monoclinic phase. However, upon support modification by La2O3, significant effects on the physicochemical properties were observed due to the monoclinic-to-tetragonal ZrO2 phase transformation also affecting the catalytic activity. As a result, superior activity on the La2O3 modified Ni/Zr catalyst was achieved, while no relevant change in the surface properties and activity of the catalysts was detected after doping by CeO2. The peculiar behavior of the Ni/La-ZrO2 sample was related to higher dispersion of the active phase, with a more pronounced stabilization of the t-ZrO2 phase

    Workplace violence against healthcare workers during the COVID‐19 pandemic in Sudan: A cross‐sectional study

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    Abstract Background Workplace violence (WPV) against healthcare workers (HCWs) is a growing global issue. During the coronavirus diseases‐2019 (COVID‐19) pandemic, violent attacks on HCWs have been documented worldwide. This study aimed to investigate the magnitude and pattern of WPV among HCWs in Sudan during the COVID‐19 pandemic. Methods A web‐based cross‐sectional study of WPV was conducted among registered medical and health workers (pharmacists, physicians, dentists, nurses, laboratory technicians, and administrative and paramedical staff) during the COVID‐19 pandemic in Sudan. Data were collected from August to December 2021 using a self‐administered questionnaire distributed through social media platforms. Results A total of 792 HCWs returned the online questionnaire. The mean age was 33.5 ± 8.6 years, where more than half were females (54.9%) and working during the day shift (58.8%). During the COVID‐19 pandemic, three out of every four participants (78.3%) reported experiencing violence, with 65.8 % experiencing it more than three times. The common types of violence experienced were verbal (91.6%), physical (50.0%), and sexual abuse (11.0%). The emergency department reported the highest number of violent incidents (46.9%). Half of these violent events were not reported (50.3%), primarily due to a lack of a reporting system. The demographic factors that were significantly associated with exposure to violence were participants’ occupation (p < 0.001), age (p = 0.001), marital status (p = 0.002), and years of working experience (p = 0.020). Conclusion WPV was rampant among the HCWs in Sudan during the COVID‐19 pandemic. The current findings are presented to draw the attention of policy leaders and stakeholders in Sudan to this alarming problem prompting the pressing need for policy and system interventions
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